I started my project with a 3.1 TGP engine and found a bent rod, I then started a search for a 3.4 DOHC engine, but have now finally settled on the 3500 LX9 engine that purchased only for the forged crank to stroke my DOHC, the DOHC deal I had fell through so here is what I have settled on… a stroked 3500 turbo engine.

For those of you know me, I appreciate all the advice and help over the past year you have given and sometimes had to force feed me. It has not fallen on deaf ears!

I will be documenting the entire build with lots of pics and cheesy story lines and hope you guys will tune in.

So here it is…

I have been hard at the math behind stroking my 3500, I have found several pieces of information that need to be accounted for…

The advertized 5.9 length rod for the 3500 is actually 5.827"

The piston sets slightly (.020) above the deck, this number is represented in the 3500 as -.020 in speaking with the Diamond piston guy I discovered that when a Piston Deck Clearance is represented in negative numbers (-.020) it means how far above the deck the piston is not how low it is in the hole.

This exercise is to see how much extra stroke and how long of a rod I can use, make no mistake I plan to squeeze as much as possible out of this engine as I can without crossing the magic 1.70 rod to stroke ratio, not exceeding this number will ensure that piston will not wear too quickly among other problems that come with falling below 1.70 rod/stroke ratio.

The first place I can get extra room is the piston, but there is no advertized PCH here is the math I used to come up the PCH for a stock 3500 LX9 engine…

(1/2 stroke + rod length + desired piston deck clearance) - block deck height = required piston compression height.

½ Stroke
Stroke 84mm or 3.3070036440000003” Divided x 2 = 42mm or 1.6535”

½ Stroke = 1.6535” or 42mm

Rod Length = 5.827” or 148.0058mm

Piston Deck Clearance = -.020” or .508mm

S 1.6535” + RL 5.827” + PDC -.020” = 7.4605” or 189.49669999999997mm

Block Deck Height = 8.818676384” or 224mm

BDC 8.818676384” Minus S+RL+PDC 7.4605” = 1.358176384”

Piston compression Height = 1.358176384” or 4.4976801536mm

The PCH for a turbo piston according to most piston manufactures should not fall below 1.250 PCH, this ensures that the ring package is robust enough for a turbo application.

With this we subtract the 1.250 from our stock 1.358176384 PCH

= .108176384” or .7476801535999997mm

.108176384” is how much shorter the custom piston will be vs the stock piston, the extra can now be used for a longer rod or more stroke.



Custom pistons 88$ a piece at Diamond Piston

The second place to get more material is from the 3500 stock crank, the rod journals are 2.249. These journals can be offset ground for more stroke or to dial in a particular rod length, reducing the journal to one of several popular SBC sizes 2.1, 2.0 or Honda rod journal sizes of 1.880 and 1.850 will give us some more stroke, for this exercise I will be using the 1.885 just to see how far I can push the envelope.

1.850” minus 2.249” = 0.399” or 10.1346mm



If we add the extra from the custom piston .108176384” and the extra gained from grinding the crank .399” we come up with a total of 0.507176384”

Total available material = .507176384” or 12.882280153599998mm

Now the trick is to find a rod and stroke combination that will fit inside of our available material = .507176384” or 12.882280153599998mm

If we start with a 6.2 inch rod which is .3” longer than stock, convert .3” to mm and we get = 7.619999999999999mm

Subtract the .3” or 7.619999999999999mm for the 6.2” rod from our TAM of 12.882280153599998mm we still have 5.262280153599999mm left over.

Before we commit to the 6.2 rod we need to make sure the rod to stroke ratio is acceptable, stock stroke is 84mm if we add 5mm of stroke from our left over TAM of 5.262280153599999mm we can get a rod stroke ratio.

To get the Rod/Stroke Ratio we convert 6.2 into mm = 157.48 we then divide our stroke into the rod length and get a RSR of 1.7694382022471910112359550561798
This number should not fall below 1.70, so we see the RSR for the 6.2” rod is an easily acceptable 1.76

This leaves us with only .262280153599999mm or 0.010325731234572338”
This is a little over .010 or 10 thousandths spare material (not much)

These numbers are purely conjecture until I pull the engine down (hopefully this weekend) to take actual the measurements.

If this all works out a 5mm increase in stroke and 40 over on the bore I come up with bore 95mm and a stroke of 89mm bumping displacement 3.8 liters in a nicely over square package with some serious dwell time added from 6.2 rods

Add a turbo and 10 lbs of boost and it should make some real HP, all this should make for a long lasting durable package that your little sister could drive to school as long as she keeps below 3000 RPM

You say “Scoob it sounds expensive” not really when you consider what you will get for the price.

Diamond Custom pistons = 88$ a piece or 524$ for 6

Crank offset grind = 250$

Used NASCAR Carrillo rods ebay 250$ (lots available)



Narrow SBC rods 75$

Total 1099$

1099$ for a completely forged custom rotating assembly that’s insanely cheap try to set up a SBC for that cost.

Wish me luck, pics and hard numbers to come very soon.

Correction:

The second place to get more material is from the 3500 stock crank, the rod journals are 2.249. These journals can be offset ground for more stroke or to dial in a particular rod length, reducing the journal to one of several popular SBC sizes 2.1, 2.0 or Honda rod journal sizes of 1.880 and 1.850 will give us some more stroke, for this exercise I will be using the 1.885 just to see how far I can push the envelope.

For this exercise I will be using 1.850 not 1.885

I know it's your build and I too have done things just for the sake of doing them but, just use the 3900 and install a 3400 cam. It has 9.8 compression, more displacement and better heads. I really don't see any beneifit to what you are doing. Good luck though.

Thanks for the vote of confidence and criticism, and yes you are right the 3900 is one sexy engine, it shares a bore size with the LS1 (good aftermarket piston selection), has oil squirt for all six pistons, a larger displacement and makes very respectable HP and torque numbers, these are the things I like.

On the other side of the coin the 3900 intake is far from a performance item, not that there is no merit to the idea, but it is designed for economy and a 250 HP not 350 HP engine, while you can open the manifold for better flow you can not increase the valve mechanism size and you will be hard pressed to convince me that an obstruction in the intake will make for better flow numbers.
I am also not interested in the extra weight of VVT components I will not be using robbing the engine of horsepower.

Some of the pros of the 3500 are that bigger is not always better (smaller engines turn up quicker) I already have it, there’s no VVT and has a standard style manifold that can easily be modified.

I look at it as a learning experience as well as good fun. The custom nature of projects like this become a part of you as you learn, invest time and put your hard earned cash into them.

Almost anyone can bolt on some aftermarket parts and make some HP, how long the engine will last and how far it can be pushed is something else all together.
There is a reason Hotrod engine builders get paid a ridiculously amounts of money, it’s not what they do it’s what they know from lots of experience that you pay for.

“There are many like it but this one is mine”
Full Metal Jacket

Thanks for the interest

quote Originally posted by Scoobysruvenge: The second place to get more material is from the 3500 stock crank, the rod journals are 2.249. These journals can be offset ground for more stroke or to dial in a particular rod length, reducing the journal to one of several popular SBC sizes 2.1, 2.0 or Honda rod journal sizes of 1.880 and 1.850 will give us some more stroke, for this exercise I will be using the 1.885 just to see how far I can push the envelope.

Isn't that going to make the crank weak?

The short answer is yes, however 60D engines traditionally use a 2” journal on their cast cranks and have been pushed to over 400 hp with out fail, the 3500 crank is a forging and is a far superior piece vs the cast cranks.
I also asked my machinist about this and his answer was he had no worries at grinding the crank down to 2” and pointed out the 60D crank has no Siamese journals to weaken the overall design like many other cranks and stated he would have no second thoughts grinding it to Honda journal size as long as the engine was kept below 7000RPM, of course he makes no guarantees just as any other speed shop.
He also pointed out that most people aren’t even aware that 60D engines have dominated the California and mid west desert racing scene for years and has supplied some serious HP for off road vehicles in that racing community for years with great success.

One thing is for sure we are going to find out soon enough, thanks for your interest.

quote Originally posted by Scoobysruvenge: Thanks for the vote of confidence and criticism, and yes you are right the 3900 is one sexy engine, it shares a bore size with the LS1 (good aftermarket piston selection), has oil squirt for all six pistons, a larger displacement and makes very respectable HP and torque numbers, these are the things I like. On the other side of the coin the 3900 intake is far from a performance item, not that there is no merit to the idea, but it is designed for economy and a 250 HP not 350 HP engine, while you can open the manifold for better flow you can not increase the valve mechanism size and you will be hard pressed to convince me that an obstruction in the intake will make for better flow numbers. I am also not interested in the extra weight of VVT components I will not be using robbing the engine of horsepower. Some of the pros of the 3500 are that bigger is not always better (smaller engines turn up quicker) I already have it, there’s no VVT and has a standard style manifold that can easily be modified. I look at it as a learning experience as well as good fun. The custom nature of projects like this become a part of you as you learn, invest time and put your hard earned cash into them. Almost anyone can bolt on some aftermarket parts and make some HP, how long the engine will last and how far it can be pushed is something else all together. There is a reason Hotrod engine builders get paid a ridiculously amounts of money, it’s not what they do it’s what they know from lots of experience that you pay for. “There are many like it but this one is mine” Full Metal Jacket Thanks for the interest

This whole thing is rediculous. First of all, I'm honestly trying to help. Not talk down about you or your swap. Both the 3500 and 3900 came from commuter cars, not race cars so there goes that arguement. There is no restriction in the intake. The variable intake, if that is what you are talking about simply opens and closes making a short/long runner setup but each bank is still grouped together. As far as you having a 3500 already, that's true but a low mile 3900 is still cheaper than all your machine work. I doubt you'll be using the stock cam in the 3500 so that cost balances with the exception of cam spacers to use a 3400 cam in a 3900 and delete the vvt. If you want to do it the hard way, I'm cool with that, just trying to help. The one upside to the 3500 that I can see is it would be easier to run obd2. Do you plan on running obd2?

Thanks for trying to save me some work and some cash and again the 3900 would be a good choice for a Fiero swap and yes both engines are not race engines, I appreciate you helping me with my point.
The 3900 intake has less potential to be modified as a street/strip performance manifold due to very nature of its design.
I appreciate your enthusiasm, but the VVT intake is indeed restrictive. I have included some pics from PFF member Joe Upson who probably knows more about these engines here at PFF than most. Take a look.





Any time air must change direction flow is interrupted without exception, as the mechanism moves the air is moved to a shorter or longer tract thus changing directions the mechanism achieves this by being in the way of the air coming from the throttle body thus restrictive.

In addition the mechanism can not be modified to flow more air without increasing its size of the mechanism (no such after market available) or one could go through a lot of time and money and make one I guess, but whay pay for restriction.

The mechanism makes for a good economy car intake but if you really want HP get one that has no such restrictions and can be modified to handle the increased flow free of obstructions. People spend thousands of dollars to flow intakes to achieve the least amount of restriction as possible.

I also included one of Joe’s pics of the VVT phaser and camshaft.



I was unaware that the 3400 cam would be a bolt in thanks, but I will be using the stock 3500 profile or something very close in a billet and it should work very well with the turbo.

Getting rid of the VVT is a no brainer.

The cam is obviously heavier note the girth of the end of the cam that bolts the phaser to and look at the weight of the phaser I’m sure its measured in pounds not grams.

As far as stroke bore and configurations go engines can share the exact same displacement and perform completely different depending on whether the is an over or under square engine and how much over or under square the engine is changes the dynamic of the engine an example of this would be the chevy 350 put in every thing from a Corvette to a pick up truck.

So for me the 3500 is a better choice, but not everyone sees it my way obviously.

Thanks for your interest.

Ok, but the intake valve isn't a restriction. The air comes into the throttle body and hits a divider that seperates the front and rear banks. when open, the banks have a shorter runner length. when closed, they have a longer runner but are still grouped together. The airflow never changes direction. Good luck with the swap.

Just something to think about. I don't know if this would be a problem or not. But with the longer stroke, would you be pulling the piston out the bottom or close to it. I know if you stroke a duke much you have to use longer rods to avoid this problem. Just something to check.

------------------

85 GT 3.4
14.9 @ 90 1.9 60' Old TH125/3.06
Unknown New 4T60/3.42

quote Originally posted by Lilchief: Just something to think about. I don't know if this would be a problem or not. But with the longer stroke, would you be pulling the piston out the bottom or close to it. I know if you stroke a duke much you have to use longer rods to avoid this problem. Just something to check.

x2. The lack of cheap longer rods is what's keeping my 3.625" stroke Duke from completion.

I had not considered the piston coming out of the bore at the bottom of the block (until now)

The shorter custom piston will give back .7mm of the proposed 5.08mm of stroke increase. This leaves the custom piston 4.33mm deeper in the hole than the stock piston.

I should have the 3500 torn down and ready for measurement this week. I will let you know what I come up with, Joe Upson may already be privy to this information. Joe????????

The piston may need to be notched and the block clearanced to make room for the longer as well.

I was also worried about there being enough clearance in the pan, but I think I should be OK.
The smaller journal rod I will be using should not end up any deeper in the pan than the stock piece and may even be a little shallower as I am reducing the journal size to get more stroke not adding material.

How will it affect the windage tray is another question that needs to be answered, but as with the pan clearance I think I will be OK here as well.

Thanks for the extra pair of eyes, I’ll let you know what I come up with when I get some hard numbers..

Welcome the newest member of the family, I got this Cobra Mustang blower with 16,000 miles for 350 $ shipped to Virginia and should be on its way via snail mail as we speak. (5-7 days)



Mmmm Blower…

Yes that’s right a blown 60 Degree V6, after looking at turbo set ups and all the plumbing that’s needed I have decided to go supercharged with my engine.

With the bore and stroke I will be using I should be able to get 275 HP easy if not 300, if we add the blower to that number we get a 40% increase in HP, for 275 that comes up to be 385 HP and for 300 it is 420 HP.

Those are some pretty sick HP numbers aye, should be fun.

I started with a lot of research on roots style blowers, specifically the M90 and M112 Eaton blowers and settled on the M112.

I used an M112 engineering schematic of the blower to set up the following scenario..

The flange bolt holes they measure 8.7” x 15.0” the blower from bottom of flange to top of blower is 5.36” tall.



I spent most of yesterday evening measuring and brain storming on how to implement this on my 3500 engine and can see it will definitely work.

Here is the general plan…

Measuring the 3500 intake from the throttle body side we see a total height of exactly 3”



I need a flat place to weld my mounting plate so I will need to trim the radius of the top of the intake down to the level of the bolt holes that hold the upper intake.



This removes exactly one inch from the stock 3500 intake leaving a flat level surface to mount the blower.



If we looked at the intake from the top you would now see a roughly 9 x 12 inch hole looking directly down into the intake.



The next step is to cut the throttle body neck off and weld a blank in its place as we will now mount the throttle body to the blower.



The next step is to weld an adaptor plate to the top of the intake.



The plate will actually be no wider on the short side of the intake, but it will need to be longer on the back and front sides. The plate will measure 10 ½ x 15 ½ and will need to hangover by 1 ½ inches on each end.



The factory Cobra intercooler mounts on the smaller flange inside the blower as seen below. This smaller flange measures 5 x 11 inches.



There is 1 inch to the bottom center of the intake and 1 ½ inches of recess in the blower for the intercooler to tuck up into.
This gives us 2.5 inches for the intercooler, this is not enough I need 21.5 inches worth of intercooler to cool 400 HP, 9 x 9 x 3 ½ or any configuration that comes up to 21.5 inches of cooler will do the job, for example 8 x 10 x 3 ½ or 6 x 12 x 3 ½ and so on.

With only 2 ½ inches of room between the Blower and the upper intakes lowest point makes it hard to put a 3 ½ inch cooler in only 2 ½ inches of space, fortunately for me I still have to weld an adaptor plate on.

If the adaptor plate is made 2” thick this gives me 4 ½ inches, the extra inch will be necessary so the cooler is not slammed to the bottom of the intake.



The question now is can I get 21.5” of intercooler is the space I have created?
The removal of the radius at the top of the intake has left us with a hole roughly 11 x 9.



Using a 3 ½ deep core we get 11 x 9 x 3 ½ giving us 24.5 inches of total cooler. This exceeds the 21.5” needed for 400 HP. All is well.



If all my numbers come out clean I should looking at an assembly 6 ½ inches taller than the naturally aspirated intake height of my 3500 engine.

Blower 5 ½ inches added = +5.5

Adaptor plate added = +2.0

Upper intake 1 removed = - 1.0

Total added height 6.5 inches.

This is what I have so far, I should have the blower next week and will wait to continue with the increase in stroke and bore until I finish using the engine to dummy up the blower.

Thanks for the interest.

I did some looking and it seems that aluminum plate can be had at a reasonable price on Ebay. I called a couple of local metal suppliers and hit the floor when they all gave me a price for a 15” x 11 x 2 ½ piece of aluminum plate.. all over 200$ smackers!

So I looked around on Ebay and found many examples of plate for a much more reasonable price.



Now that’s more like it.

quote Originally posted by Scoobysruvenge: I did some looking and it seems that aluminum plate can be had at a reasonable price on Ebay. I called a couple of local metal suppliers and hit the floor when they all gave me a price for a 15” x 11 x 2 ½ piece of aluminum plate.. all over 200$ smackers! So I looked around on Ebay and found many examples of plate for a much more reasonable price. Now that’s more like it.

Nice price indeed. How much do you think it would cost to mill it down into something you could actually work with, rhetorical question. McMaster-Carr can get you much, much closer to exactly what you need although a bit more expensive but not unreasonable. They also list different alloys in the event you want something stronger.

When are you going to stop with all this "Desktop Performance" and actually build something? The ideas are great but it would be nice to see your non keyboard related handy work for a change. No sarcasm intended.

[This message has been edited by Joseph Upson (edited 02-04-2010).]

We have a mill and a lathe in the shop so getting the plate to size won’t be a problem, as far as the doing some work it should be getting started as soon as I have the blower in hand.

Yes, I do a lot of keyboard racing, but this is not wasted time, it is money saved and mistakes avoided the way I see it.

I started this project with an 88 Formula and planned to use a 3.1 TGP turbo engine I purchased for this project, not being very familiar with the 60D engines I got started last year.

I joined PFF after purchasing the car and the engine and was learning a lot from the members here on this site about the later generations of the 60D being a better platform to begin a project with, but it was too late I already bought the TGP 3.1.

Soon after I found a bent rod in the engine and decided to abandon the TGP 3.1 and select a better engine to start with per some of the PFF member’s advice.

I started looking for a new donor engine I honed in on the 3.4 DOHC engine as a good prospect with its free flowing heads.

While waiting for a low mile 96/97 DOHC engine to fall into my lap I began looking into a forged crank for it and found that the 3500 LX9 had a forged crank but the journals were 2.249 not 2”.

Armed with this information I decided to pick up a 3500 LX9 from my local wrecking yard to acquire a crank while I waited for a DOHC donor.
I got a 42,000 miler for less than 200$ (What a steal) to cannibalize for the crank.

With 3500 engine in hand, I soon found a 1996 car with a 3.4 DOHC engine with less than 100K and a busted transmission with maintenance records, the only catch was I would have to wait until December (3 months) and Christmas break to get it as the owner was away at school.

When December came I went to pick the car up and upon starting the car the unmistakable sound of a knocking rod could be heard, so there went the 3.4 DOHC I had been waiting for.

While waiting for the 3.4 DOHC car I spent a lot of time researching different engines, I had already made my mind up no matter what 60D engine I selected the forged 3500 crank was going in it and since I had to turn the crank down to 2” I might as well get some stroke out of it.

After the DOHC fell through I decided to go with an LX9 3500 (which I already had) the choice was simple for several reasons, I already had the 3500 was probably the best one though.

So there it was January 3 months wasted on the DOHC and I had now decided to go with the 3500 stroked and bored.

I began looking at the turbo plumbing and the limited space I had when my local machinist suggested a blower might make for more room and less heat than the turbo.

After a month of homework on Eaton blowers I found them affordable, dependable, prolific and effective. I settled on a M112 off of a 03/04 Cobra as the unit that met my needs the best.

So here I am a year later ready to get started on my project, but knowing I was going go with the blower I decided to wait to pull the engine down to take the actual measurements for the rod, piston and crank stroke job until I get the blower mounted on it.

I need the engine to set up the exact blower location, I’m also sure I will need some pulley mods to make it all work, besides there’s no way I could have that blower laying around looking at me like the GEICO money mascot without playing with it.

So here is the short answer I will be in the garage the day the blower arrives to get started with this, it should be here the middle of next week.

In addition, all this armchair racing is necessary unless you are going to waste a lot of money learning as you go or by paying someone to figure it out for you.
I have also learned a lot here at PFF while I have patiently waited for everything to fall into place.

Thanks PFF members

Thanks for your interest Joe, and by the way I’m sick of waiting myself, but that’s about to change next week.

It was Thursday and the scuttlebutt going around was that we were going to get hit with another snow storm for the coming weekend and might it be here as early as Friday night.
My family and I were glued to the tube waiting for local forecast. My daughter sat in front of the fire waxing her sled and dreaming of sleeping in. My wife had stocked the cabinets for dooms day and armed herself with a stack of feel good movies and a box of tissues for the pending storm.
I had my own plans and they did not include the insanity going on at my house. I had been plotting all week catching all the honey dos that fell on the inside of the house, filled the generator and checked the transfer switch… it was all in place, it looked like I going to get some shop time.
The weatherman began to speak and my daughter broke into her snow dance for good luck, my wife froze in place with a half eaten bon bon in hand as the report was delivered… Snow 4 – 6 inches starting early Friday morning… The celebration went into the night.
When I woke in the morning, I hurried to work and put my half day in and headed to the shop to get started.

I began by rolling the 3500 out, getting some tools and taking a few measurements for the pending intake reduction surgery… The patient was ready.



I removed the intake.



Inspected it for damage or obvious irregularity and found none.



Removing the throttle neck and plate were next as they are no longer needed.



Knowing were some supports casted inside intake I carefully used a cutoff wheel and a sawzawl to out line the top of the intake.



I then removed half of the top to get a good look at what not to cut.



This revealed the throttle throat extending into the intake about 4 inches with 3 cast legs above to support the top of the intake.



Cutting two of the support legs and taping the top with a plastic hammer I removed the rest of the cutout.



I rough cut the throttle body tunnel and supports out of the intake.



Now that I had the intake cleaned out it was time to mark it and trim it down as close as possible so I would not need to make so many passes with the mill.
The idea here is to cut the intake down to the mounting bosses so that I have a flat level surface to mount the blower plate.



Using the sawzawl I removed the rest of the excess material. You can see I tried to get down as close to the bosses as I could without removing too much. The sawsawl is no scalpel you know.



A few quick measurements…







A quick clean up…



A test fit of the manifold shows the blower plate will hang over 1.5 inches on each end, the other side is perfect and will be flush with the side of the intake.



As I was finishing all of the prep work my bro was setting up the mill the remove the rest of the excess material to provide a machined level surface to mount the blower plate.



A quick set up of the intake on the table revealed a cast boss that needed to be removed before we could set the intake level on the table.



You can see that a very minor amount of material needed to be removed for the intake to set flush. I performed this with a die grinder and a flat file.



With the intake now level and secure we were ready to get started.



We measured all the bosses, found the lowest one, milled an extra .020 off it and set the quill gauge accordingly.



This would be the finished level of the intake for the blower plate.



The milling process began, we could get .035 a pass with a good finish, so it was going to take a little time.



After the first pass all the sawsawl rough cut was gone and we set in on taking it the rest of the way down.



Finished intake milled to correct depth.



Time to get rid of the supports and mill some of the leftover TB tube out so the hand finishing of these areas will take as little effort as possible.









With the intake machined down to a finished height of 1 ¾ of an inch and all the excess material I could remove with the mill from the inside I was out of time.



I will leave the intake on the mill to index the bolt holes so the pattern can be transferred to the blower plate with out ant further measurements on the mill.

I will post the rest as it happens, I still need to de-bur every thing and blend the milled surfaces inside the intake to finish this. Shouldn’t take long.

After waiting over a week for the Money Order sent last Wednesday, it cleared the bank and my supercharger was shipped today.

I started assembling some of the aluminum necessary to make this happen, using the upper I cut is out due to flow and height issues.

Here is how it will go…



This view is from the driver’s side of the engine, rather than mounting the intercooler below I will set a remote cooler next to the intake where the throttle body used to be.

This will be achieved by building a plenum below the blower to push the air out to the intercooler. The ducts on the side will return the cool air back to the lower intake ports.

I started picking up material to do the job yesterday, here is what I have so far…

This will be cut in half and trimmed to two pieces of 1 x 3 x 15 for the lower blocks.



The box tubing will be cut down to 1 ½ and used as the return ducts to the lower intake seen on the left and right of the discharge area.\ in the diagram above.



The 5020 was selected because it can be easily molded and will be used for the base plate.



The short of it…



Thanks for looking, I will be posting pics and information as I get the parts and assemble them.

quote Originally posted by Scoobysruvenge: I finally found the actual compression height of the 3500 factory pistons and it is 1.1, far from the 1.250 I need for a forced induction piston package.

You better check that again, the 3500 and 3900 differ by bore diameter dimension wise, my piston compression height is 1.304". The actual rod lengths are different in some cases as GM installed both 5.827" and 5.9" rods in the 3900 but that doesn't account for the missing compression distance from what you have listed.

http://60degreev6.com/forum...lk-3500-style-t39445

Why not stay with stock rods? Short of poor tuning (detonation) or hydrolock, I can't see you having too much of a problem, whereas mixing in aftermarket stuff for an application it wasn't intended for opens the door for error.

quote Originally posted by KurtAKX: Why not stay with stock rods? Short of poor tuning (detonation) or hydrolock, I can't see you having too much of a problem, whereas mixing in aftermarket stuff for an application it wasn't intended for opens the door for error.

Not possible for him to use the stock rods with an offset crankshaft grind unless he has it welded up first and that would cost a fortune. It's not that complicated as long as the machinist knows what he's doing. Small block rods are the choice upgrade from my understanding. My concern would be a rod journal less than 2.00" in diameter on a stroke greater than 3.31"

It is hard to argue with a guy with piston in hand, I got my information from GM factory piston manufacture manual. It shows 1.1” only for 2004 – 2005 non vvt 3500 v6.

This information could be wrong… but after hearing the number it made sense given the 3500’s low deck height of 8.818

I will be pulling the crank soon and will let you know what I measure, is your engine a 2006 or 04 – 05?

Let’s do the math in reverse using the 8.818 deck height…
I am using a 5.7” rod a 3.5” stroke (divide x 2) = 1.75

Add 5.7 + 1.75 and you get 7.45

Now subtract 7.45 from 8.818 and you get the height of my custom piston or compression height = 1.368

So no matter I’m ok with the 5.7 long rods.

Let’s do the 3500 numbers from the 60D site…
Rod 5.9 + ½ stroke (3.307 / 2) 1.653 = 7.553 – Deck height 8.818 = 1.265 compression height.

Let’s do your numbers at 5.827 Rod length.

Rod 5.827 + ½ Stroke 1.653 = 7.48 – Deck height 8.818 = 1.338

Those don’t add up to 1.304 unless your piston is out of the hole 34 thousandths (.034)
I could see .020 out of the hole but not .034
The Factory GM numbers above don’t add up to 1.1 either so I will trust my math.

Anyway, if I have missed something let me know, thanks for extra eyes Joe

06 is the cutoff year for non VVT 3500 production. The VVT 3500 has a 3" stroke. I'm sure stock isn't 1.1" compression height on any of the engines. I don't recall the pistons protruding above the deck on the 3900 but I'm certain about the compression height because I compared it to the replacement pistons which have a compression height of 1.314.

As far as the deck is concerned,
8.818 - (1.304 + 5.827 + 3.31/2) = .032 below the deck not above.

A 5.9" rod would put the piston above the deck, who knows what the true specs of the engines are and whether or not the different rod lengths are the result of some engines being flex fuel compatible.

quote Originally posted by Joseph Upson: Not possible for him to use the stock rods with an offset crankshaft grind unless he has it welded up first and that would cost a fortune. It's not that complicated as long as the machinist knows what he's doing. Small block rods are the choice upgrade from my understanding. My concern would be a rod journal less than 2.00" in diameter on a stroke greater than 3.31"

That's right I forgot he was insisting on stroking it.

Edit to say that sounded really bad. I meant increasing the magnitude of piston displacement in the bore.

[This message has been edited by KurtAKX (edited 02-12-2010).]

Yes Kurt, I plan to stroke the engine from 84mm to 89mm.
The concern for a small journal and excess stroke is not one that bothers me for several reasons.
Small Chevy guys run 1000 HP on 1.850 journals with 6.2 rods or longer at full throttle for 500 miles strait at much higher RPMs with a Siamese journal crank.

The 60D cranks all have a separate journal for each rod, not shared like the SBC style cranks.

I plan on a close to stock RPM range 6500 or below, it is RPM that kills a crank and rod.

The Oliver rods are over 100 grams lighter and after they are narrowed they will be even lighter.

As far as the stock rods are concerned, one of my TGP rods was bent on a my relatively low mile motor, so I don’t have a lot of faith in the stock rods however misguided I may be.

Besides guys where’s your hot rod spirit, unless you make it or modify it your really just bolting some parts on.

Desperate for fuel for my funk engine I decided to call around the local metal shops to see what kind of drops they might have on the cheap.

Local company BMG had some drops for me to look through, so I made the pilgrimage to BME to see what they had.



I scored a piece of 3 x 3 OD x 1/8 box tube 36 ¼ long, had it cut in half and walked out only 8$ light (not too shabby)



I went back to the shop with my new find to test some of the configurations I’ve been working on.



With boxes in hand I set them on the block to get a look at how all this was going to work.



The 3” box fit nicely against the stock fuel rails.



There were going to be some issues with the stock fuel rail that will need to be changed… Pressure check valve relocation and some tube changes will be needed, but should be very minor.





A coolant hose will also need to be relocated. This should prove easy as well, for now a rubber mallet has made room for the box to mount flush.



After cutting the stock plenum bolts and turning them into temporary studs, I drilled some holes and mounted the boxes.



From the other side.



With the boxes in place I cut a piece of the 2 ½ ID tube 16” long and then cut it in half .



I then clamped the two halves together to take a quick measurement for the belly of the beast. (Perfect)



Now for the test fit between the plenums.



Notice, I have placed these at an angle to reduce the blower plenum Cu



Another shot.



From the back.



All clamped up.



Now I must wait for the blower to arrive, it will need to be moved back or forwards to line up the pulley.

Should be here this week sometime along with the rest of the aluminum.

1) I'm digging the IC routing so far. I hope your TIG skills are able to keep up with your imagination. Also, is this really gonna clear the decklid?

2) I just looked back through some of your original thread. Its funny how your build thread is for something completely different than it started out as. Reminds me of the larva-cocoon-moth phase change thing.
a. TGP Motor turbo
b. DOHC motor turbo
c. 3x00 pushrod S/C

I guess you're not incapable of changing your mind.

Kurt,

Thanks, my tig skills aren’t bad but my bro is better so I will let him cut the beads on the intake.

The final height of the in take, no matter what configuration I use will be no taller than 3.5” the stock intake was 3” so I am picking ½” the blower is 5.7” tall. This gives me at most a 6.3” rise from the stock intake.

If we look at some pics from Lilchief and his TGP build we can see something very close to the height of my 3500 engine.





It looks to be 2 – 4” of room to the roof of the deck lid, so I figure my blower will set up 2 - 4” above the deck lid, easily fitting under a small scoop. I also plan to low mount the alternator on this engine.

If I had bought a M112 blower off a Range Rover I could have reduced 6.3” to 3.3” above the stock intake height as it blows from the back already but the cost would have been more than double what I paid for the Cobra blower.

I have been working on some different configurations using power point to mock them up so I have some idea how much and what size metal I will need.

There are a lot of variables here and I want to minimize the design to keep it compact. Here is the configuration I am looking at right now.



I was having trouble sourcing Air to Liquid intercoolers with a 1.5” inlet/outlet that are not custom made. So I will be using a single 3” outlet to the intercooler.

You can see I would like to run water or maybe even a thin oil through the cavities in the intake to cool the charge some before it reaches the intercooler, although I’m not sure which would work best ?????????

Plenum size was also a major concern and drove the design from the beginning, I used Corky Bell’s rule of thumb.

Per Corky Bell plenum should be engine 50% to 70% of the engine size or several times a single cylinders volume.

3.8/ 231 Cu @ 50% = 115.5 Cu @ 60% = 138.6 @ 70% = 161.7

3.8 / 231 Cu 1 Cyl Vol = 38.5 x3 =115.5 x3.5 =134.7 x4.0 =154.0 x4.5 =173.2

As you can see figuring both plenums I am well into the 60% range and should be able to move enough air without restriction.

Thanks for your interest

When you are through changing, you are through.
~Bruce Barton

quote Originally posted by Scoobysruvenge: In my mind the horseshoe configuration is the best choice, it will keep the velocity up with its smaller 96 Cu size and has almost 25% more surface area around the water jacket.

I don't think blower exit is a place its important to "velocity up". You're not using air inertia to aid cylinder filling in this scenario here, feeding an intercooler.

After a lot of conjecture and planning I began to cut some metal.

I’ve been putting this off as long as possible so that any changes in design wouldn’t cost me any expensive metal.

With that said it was time to start fabing up some of the parts… I started by chocking up one of the halves I had already cut in the vice to quarter it.



Now that I had some quarters to work with it was time to start fitting it together.



With my trusty vice grips I clamped the pieces together to see how well it all fit together.



Not bad for a hack job with a sawzawl I will have to file in a few places to get it to fit super tight for the weld job, but it will be very minor.





It was time to fit this piece into the puzzle.



Dropped between the boxes for a loose fit.



Loosening the nuts on my boxes and a quick squeeze for a tight fit.



Not too shabby for a starter kit.



Next step was to cut some more halves so a quick score with the chain cutter and I had a nice strait line to follow.



A couple of chops with the portaban and we have our two halves.





A quick of test fit to see how it will all look.



Now the 3x3 box wall needs to be removed to complete the plenums.



Unfortunately it was time to clean up and head home for supper, after all it was fried chicken night.

With all my things put up I looked back one last time and tuned out the lights, until next time.



Thanks for tuning in.

Loving this build thread! its great to see some original engineering taking shape!

+ for you!

Gandalf,

Thanks for the vote of confidence. I crunched a lot of numbers, read a lot of printed material and bugged a lot of people to hopefully get it right.

Thanks for tuning in.

After a long two week wait my blower finally arrived, I can now get some real world measurements.



A search last week for the trunk key turned up nothing. I now believe I had given the trunk key mistakenly to the guy who bought the GT parts car so I went and got my spare key.

I pulled the cover and chucked up my new trunk key in my cordless drill, a quick bore of the cylinder and the twist of a large flathead and I was In.



The first thing I wanted to know is how much room do I really have to the deck lid?

I measured the stock Fiero intakes… 10” Tall… My 3500 intakes measure 9”… an inch saved.

Now the question was how much room between the deck lid and the stock intake?

I half way crushed a pop can (no free advertisement here) and set it on top of the intake.



I closed the deck lid several times until I felt no extra resistance and came up with 2 ¾”, so lets call it a safe at 2 ½ inches.



This gives me 3 ½ inches of room between the 3500 plenum and the deck lid.



I am not using the 3500 plenum, so this gives me a total of 6 ½ inches to work with.



After measuring the blower it is indeed 5.7” tall but the throttle intake plate puts the blower height at 6 ½ inches, exactly how much room I have between the deck lid and the lower intake.

So if my custom manifold measured 3 ½ inches tall, the blower would set 3 ½” above the deck lid. This would fit easily under a small scoop.





All is not well though sports fans…

The crank pulley/balancer sits directly below one of the vent grills, if the blower sets above to deck lid then the pulley shaft will be above as well interfering with the grill where there is no hood scoop.



So now I have to re-think this… I have several solutions…

I could mount the blower down low on the trunk side of the engine, rough measurements show that this quite doable and not so tight. This eliminate the need for a scoop.

I also have an idea on how to slam the blower to the lower intake.

Make no mistake the blower will fit, but it looks like I am going to have to work at packaging a little first.


Some of you may have heard me post about my bro’s Mustang and the Megasquirt he is using for the fuel system.
It’s in the shop for a few leaks… 20 pounds of boost has a way of finding the tiniest of leaks, after these are fixed he is going to throw another 5 pounds to it.



Did I mention that the Megasquit was easy to tune and works awesome, after seeing it in action there is no way I would waste my time trying to get the stock stuff to work.