OK, please don't flame me for this, but I plan on going carbureted when I do my 3400 engine swap. The only option is to use some ported iron heads, but I would like to take advantage of the aluminium heads.

Has anyone fabricated a carbureted manifold for the aluminium heads, or any ideas on how this could be done? I'm thinking the lower manifold could be adapted, but I'm not sure.

By the way, I do not really want to discuss the benefits of fuel injection, etc. I've been over the subject 100 times, so it's beating a dead horse at this point.

Thanks!

Not that I am aware of. Shouldn't be too hard, use the stock lower intake manifold and build an upper plenum and use a couple Weber DCOE's. I know there are a few ITB intakes for the early 3100's floating around, not sure how easy it would be to convert them to a carb set up, though; might also look into that...

[This message has been edited by topher_time (edited 01-12-2010).]

*SIGH*

I guarantee that no one on this forum has done anything like that... You could try asking at 60DegreeV6.com but I don't think that you'll have any luck there either...

Iron heads and an S-10 manifold are probably going to be your only friend on this one...

I have an Edelbrock 4 barrel intake coming off mine some time in the spring. I am putting on an Offenhauser on the new build.

The standard carb'd intakes are made for the iron heads unfortunately. However, our friend Oreif did 234 hp on a pushrod 3.4. It seems to me that if you can make the iron heads work, you can still get some go power.

Arn

Yeah, I know you can make some power with the iron heads, but from what I've read, the aluminium heads still flow better and it would save the time to port them, plus 20 pounds or so. I looked all over 60degreev6 and I've checked out wot-tech. No one is really into carbs but me, I guess. What can I say, I'm a simple man.

Hey Mike, there are a few guys on the forum that are carb guys. Not too many v6 guys, mostly sbc guys, but we are here.

Sure the aluminum heads flow better, but, not that much better. Like I said, Oreif got 234 hp on his 3.4 and I don't think he hit the max that is do-able.

Stay with it.

Arn

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http://www.tcemotorsports.c...view&id=15&Itemid=28

Check out the one at the bottom of the page. If you could find 2 weber 3 barrels you might be in business. Would need alot of tuning though.

quote Originally posted by Arns85GT: Sure the aluminum heads flow better, but, not that much better.

Feel free not to back that one up...

quote Originally posted by carbon: Feel free not to back that one up...

yea, ima agree with that, i think you need to double check some numbers, the gen3 heads destroy even the best ported irons from what ive seen...

My 1990 Cavalier was an aluminum head 3.1 rated at 140 hp. My 1985 Fiero is rated at 140 hp.

I don't dispute that the aluminum heads flow better, but better is relative. A ported set of iron heads will flow around 340 cfm with the stock cam and higher lift valves.

Switching to the aluminum head is going to give you how much more? Moreover there are no carb intakes made for the aluminum heads. We know that a carb'd 3.4 can do approx 234 hp. That would be much more with boost. The aluminum head guys are getting about the same. The bigger difference is the DOHC which is clearly way ahead.

Arn

[This message has been edited by Arns85GT (edited 01-13-2010).]

i wanna do a carb'd 3800 xD

quote Originally posted by Arns85GT: My 1990 Cavalier was an aluminum head 3.1 rated at 140 hp. My 1985 Fiero is rated at 140 hp. I don't dispute that the aluminum heads flow better, but better is relative. A ported set of iron heads will flow around 340 cfm with the stock cam and higher lift valves. Switching to the aluminum head is going to give you how much more? Moreover there are no carb intakes made for the aluminum heads. We know that a carb'd 3.4 can do approx 234 hp. That would be much more with boost. The aluminum head guys are getting about the same. The bigger difference is the DOHC which is clearly way ahead. Arn

The 3.1L is first design, at 140 hp, 180 lb/ft, the 3100 is rated at 175 hp and 195 lb/ft, that's a big difference, I'm not sure how much the newer head design contributes to that but it out performs the stock 3.4L from the camaro and firebird with their 160 hp 180 lb/ft and .3 additional litres. There's no comparison that I've seen at least in terms of power output when the same modifications are performed on the iron head vs. aluminum head engines. 200+ hp on a 3100 is only a cam change and good exhaust system away. I would be looking for a way to keep the aluminum heads with a carb. The iron head motor isn't close when it comes to boost either.

http://www.60degreev6.com/c...0d40156a4869727ecf2b

[This message has been edited by Joseph Upson (edited 01-13-2010).]

Give me a day or two, I think I have a catalog around here somewhere that sold lower intakes for carbed 3.4 engines with the aluminum heads.

Anytime you consider adding a carb on an engine that originally came with a DIS you will have a problem. Even if it were possible to just make up a manifold and bolt the carb on how do you intend to run the igniton system? You can't use distributors on these engnes.

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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, 3.4" Pulley, N* TB, LS1 MAF, Flotech Exhaust Autolite 104's Custom CAI 4T65eHD w. custom axles, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

I too would be interested in this, as doing a 3.1 swap with a carb would be very easy into an 84.

quote Originally posted by Dennis LaGrua: Anytime you consider adding a carb on an engine that originally came with a DIS you will have a problem. Even if it were possible to just make up a manifold and bolt the carb on how do you intend to run the igniton system? You can't use distributors on these engnes.

If the stock intake system is being eliminated chances are the replacement parts will already be designed to accomodate the distributor. A taller distributor is about all that's necessary for the 3400 and 3100 in order for the base to clear the #5 runner from what I recall when I considered attempting to use a distributor on a complete engine years ago. The 3500 and up are near impossible to do this on because of the increased runner size overhanging the distributor plug. I doubt a carb manifold for the aluminum heads exists though, I'm sure we'd of heard about it before now.

quote Originally posted by Dennis LaGrua: Anytime you consider adding a carb on an engine that originally came with a DIS you will have a problem. Even if it were possible to just make up a manifold and bolt the carb on how do you intend to run the igniton system? You can't use distributors on these engnes.

You can always keep the stock ECM and all its sensors control the ignition, while relying on the carb for fuel.

quote Originally posted by Dennis LaGrua: Anytime you consider adding a carb on an engine that originally came with a DIS you will have a problem. Even if it were possible to just make up a manifold and bolt the carb on how do you intend to run the igniton system? You can't use distributors on these engines.

You can. I used a 3400 roller-cam block in my GT.

Unless they have changed this in the newer 3400's - the camshaft still has the gear that drives the distributor - it also drives the oil pump. The 3400 has a block off plate that bolts in place of the distributor. It has the bottom end of the distributor shaft with drive gear (that connects to oil pump shaft). Just use a distributor off an older carb'd (non-computer controlled) 2.8 S10/Camaro engine. I'm not sure if there would be any interference with the head though.

His problem will still be getting a carb manifold for the aluminum heads because they don't exist.
May have to build one. http://www.popularhotroddin...manifolds/index.html

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World of Wheels Winners
My 3.4L S/C 87 GT
& Super Duty 4 Indy #163

[This message has been edited by fierosound (edited 01-13-2010).]

If you check out fierosound's motor, you'll see that these blocks do in fact have a provision for a distributor, it's the manifold that gets in the way. Also, when I researched the history of the 60* v6, I read that the new aluminium heads were built to support 270+ horsepower. Unfortunately, gm couldn't make a transaxle to support that power, so the engines were never made that powerful by gm. I think with a carb and aftermarket roller cam with aluminium heads, that 270 hp is a doable number, hence my interest in a carbed manifold. The problem is that I can't fabricate for **** and I have to rely on someone else's skills or ideas. That's why we're here, right?

Thanks everyone!

Edit - Hey fierosound, we must have been typing about the same time - I'm just slow. Thanks for the link!

[This message has been edited by BigMike (edited 01-13-2010).]

quote Originally posted by BigMike: I read that the new aluminium heads were built to support 270+ horsepower. Unfortunately, gm couldn't make a transaxle to support that power, so the engines were never made that powerful by gm.

Except one, 270 hp HO 2006 Pontiac G6 GXP 6 spd 3900 SEMA show car. ZO6 valve springs, reground camshaft, cat back exhaust and a little cylinder head massage. I wonder what the ram air hood added to that.

It may have been limited to 270 hp by the dualmass flywheel and emissions.

It's ashame they never took it to the production line.

http://www.automobile.com/2...how-car-concept.html

http://www.60degreev6.com/f...wimage.php?i=296&c=5

[This message has been edited by Joseph Upson (edited 01-13-2010).]

That's pretty sweet. It's a shame GM had to can Pontiac. Just about the time they got it right....hey, sounds like the story of the Fiero, doesn"t it?

So, is custom sheetmetal the only way to go, or could the stock lower manifold be modified? Any Opinions? How about composite?

quote Originally posted by BigMike: That's pretty sweet. It's a shame GM had to can Pontiac. Just about the time they got it right....hey, sounds like the story of the Fiero, doesn"t it? So, is custom sheetmetal the only way to go, or could the stock lower manifold be modified? Any Opinions? How about composite?

The most practical way to go about it would be individual weber carbs mounted to the lower intake runner ports, and an after market DIS ignition system, I think MSD is one of the manufactures for that. The problem with building a custom intake is the OE intake manifold design comprising part of what should be the cylinder head to complete the valve cover seal. Perhaps if you cut the manifold just beyond the valve cover seal and welded tubing from that point to a central location for a carb and filled in all of the gaps to seal the engine you could get away with it.

Isn't the 3.9 a little different from the 3400? I think so, but I'm not sure. Part of the goal here is to use a distributor, so going with a DIS defeats the purpose. Probably why this hasn't been done.

quote Originally posted by BigMike: Isn't the 3.9 a little different from the 3400? I think so, but I'm not sure. Part of the goal here is to use a distributor, so going with a DIS defeats the purpose. Probably why this hasn't been done.

It's a little larger but what you see is basically the same hurdle. Unlike the iron head motor, the lower intake does not centrally locate all of the ports. So you'll have to get very creative even after you manage to adapt a distributor to optimize the ports for even fuel distribution.

quote Originally posted by BigMike: By the way, I do not really want to discuss the benefits of fuel injection, etc. I've been over the subject 100 times, so it's beating a dead horse at this point.

You must be one of those hairy dudes in the Gieco commercials?

Sorry, couldn't resist the jab. But seriously, the $$ spent fabricating a one-off carburetor intake would buy a really nice aftermarket fuel injection system. I know it's not what you want, but that's the facts of life. Just curious, why are you so against it?

That's a reasonable question. I'm not really AGAINST anything per se, I just prefer to build a carbureted setup. The reason is simple, literally. Carburetors are simple, and the wiring and tuning are within my personal capabilities. I prefer not to worry about re-pinning, chip tuning, and programming. I want a project that I'm comfortable maintaining and working on.

Let me just say that I believe modern computer controlled fuel injection is superior to carburetion for cold starts, tuning, and fuel economy, but this car is a hobby for me and my first priority is enjoying it. I prefer to work on a simpler machine that I can understand and tune without a computer.

I promise I'm not a cave man, but my specialty isn't mechanics. I just want to enjoy the car hobby on my terms. Let me say again, I'm in no way against modern controls, I just want to build a carbureted car.

I'd also suggest looking into an Ecotec. There are intakes available to run a pair of Weber side drafts. I've ridden in a Caterham/Super 7 with a carbed Ecotec, and lately I've been thinking of dropping my idea of a ITB 1UZ-FE (Lexus V8) for a carbed Ecotec in my 84. Engine ran smooth, pulled hard, and sounded great. It retained the DIS by a seperate module to control spark timing off the flywheel. Very minimal wiring and should be fairly easy to drop into a Fiero. I'll have to find the website, but it puts it close to hp wise as the 3400/3500, just doesn't have the low end torque, and with the availability of aftermarket parts, should be able to pull some good numbers out of it. The engines and transmissions are also cheap, reliable, as easy to come by. Might be easier to get working than a carbed 3x00.

[This message has been edited by topher_time (edited 01-14-2010).]

quote Originally posted by topher_time: I'd also suggest looking into an Ecotec. There are intakes available to run a pair of Weber side drafts. I've ridden in a Caterham/Super 7 with a carbed Ecotec, and lately I've been thinking of dropping my idea of a ITB 1UZ-FE (Lexus V8) for a carbed Ecotec in my 84. Engine ran smooth, pulled hard, and sounded great. It retained the DIS by a seperate module to control spark timing off the flywheel. Very minimal wiring and should be fairly easy to drop into a Fiero. I'll have to find the website, but it puts it close to hp wise as the 3400/3500, just doesn't have the low end torque, and with the availability of aftermarket parts, should be able to pull some good numbers out of it. The engines and transmissions are also cheap, reliable, as easy to come by. Might be easier to get working than a carbed 3x00.

Torque is a word that is higly under used when discussing performance. It took me a while and then some experience to realize that torque is what makes driving the car fun (for me), not revving the engine up to 6 grand alone. I learned the hard way after swapping in a turbo sunbird 1.8L. It ran nice but the torque compared to the V6 wasn't enough, so although we speak more often in horsepower terms, what most of us are really after is the feel of acceleration and that requires torque. I'm going to have a second camshaft reground for the turbo 3900 because I had the first cam ground for more top end without considering that the cam was already rated for peak power at 6000 rpm stock. At the fully retarded position which was slightly off being installed straight up (has about -4 deg retard at that point) I barely had enough vacuum power to brake with moderate driving and the initial few moments into acceleration from a stop the car didn't feel any faster than the low compression turbo 3100 with iron heads that it replaced.

It's hard to get a grip on planning for higher torque numbers than hp for performance because we've been conditioned to think hp. It all depends on your driving habits but in a daily driver I bet the feel of more torque would win over hp because as I've stated before, by the time you start to appreciate the additional hp you're probably traveling way too fast, unless you're on a track.

quote Originally posted by Joseph Upson: It's hard to get a grip on planning for higher torque numbers than hp for performance because we've been conditioned to think hp. It all depends on your driving habits but in a daily driver I bet the feel of more torque would win over hp because as I've stated before, by the time you start to appreciate the additional hp you're probably traveling way too fast, unless you're on a track.

+1

It also helps to look at the HP curve's rate of change across different RPM ranges. This rate of change gives a good reference to the torque that the engine is producing... if it is ramping up quite quickly then torque will be high in that area and accleration will be quick... you can also have slowly increasing HP numbers and have poor accleration due to decreasing torque, if HP is dropping off, then you're S-O-L torque wise.

This is why I hate the 4 cyl w/ 200HP vs 6 cyl w/ 200HP debate. The GM 3500 V6 is making 200HP at 5200RPM and the Honda Civic SI I4 is making 200HP at 7800RPM. The I4 needs that higher RPM to make that power because it has less torque(139@6100 vs. 215@4500) to work with. Its all about the area unde the curve. Ecotec motors are usally tuned to deliver balanced torqe stock with both HP and TQ within the 140 range for the 2.2, but I would be wary of any engine that lists something like 200HP with only a 130TQ peak for a daily driver/cruiser, might be fun at the track, but 200HP/220TQ is always going to be more fun around town...

Yes I know the torque is abbreviated to lb. ft. not TQ.

[This message has been edited by carbon (edited 01-14-2010).]

Correct me if I'm wrong, but since torque and horsepower are related, when you make more hp, you also make more lb ft., right? The key is to make more horsepower at the SAME rpm so that the torque peak is not moved. So, if an engine can make 270 hp at 5000 rpm vs 220 hp at 5000 rpm, the torque should also be higher at the same rpm, right?

I'm definitely no expert here, but that's how I understand it. I definitely want torque, this is a street car.

quote Originally posted by BigMike: Correct me if I'm wrong, but since torque and horsepower are related, when you make more hp, you also make more lb ft., right? The key is to make more horsepower at the SAME rpm so that the torque peak is not moved. So, if an engine can make 270 hp at 5000 rpm vs 220 hp at 5000 rpm, the torque should also be higher at the same rpm, right? I'm definitely no expert here, but that's how I understand it. I definitely want torque, this is a street car.

Everyone talks about making more HP but that is just a function of TQ and RPM, so it is possible to increase horsepower and decrease torque as long as RPM increases enough to offset the loss of torque... This is why you can make 200HP with only 130TQ if you spin the motor fast enough... if you are making 50 more horsepower at the same RPM then you have to be making more torque at that RPM as well...

HP=(TQ X RPM)/5250

Algebra FTMFW!

[This message has been edited by carbon (edited 01-14-2010).]

quote Originally posted by BigMike: Correct me if I'm wrong, but since torque and horsepower are related, when you make more hp, you also make more lb ft., right? The key is to make more horsepower at the SAME rpm so that the torque peak is not moved. So, if an engine can make 270 hp at 5000 rpm vs 220 hp at 5000 rpm, the torque should also be higher at the same rpm, right? I'm definitely no expert here, but that's how I understand it. I definitely want torque, this is a street car.

Actually it is the other way around. Torque is the engines power. Horsepower is the engines power over time.
A dyno measures the engines torque over time to calculate it's horsepower.

As for head flows and such. The original Gen II 60* V-6's had aluminum heads. Stock the heads flowed slightly better than a stock Iron head. The Gen III 60* V-6 aluminum heads flow stock what the H.O. cast iron heads flow mildly ported. A full port/polish on an iron head will have more flow than the stock Gen III aluminum head.

Here are some numbers to consider:
Stock Iron Head: 280 cfm max. (used on X-body and S-series trucks with carb)
H.O. Iron Head: 350 cfm max (this is the head used on Fiero's and 3.1L/3.4L with iron heads.)
Stock Gen II aluminum head: 370 cfm
Stock Gen III aluminum head: 390 cfm
Stock Gen III "Ram Air" aluminum head: 405 cfm.

My H.O. iron heads after porting and polishing: 420 cfm. (actually tested on a flow bench)
Engine output based on chassis dyno results: 232hp / 249 ft/lbs torque.

Falconer Racing Iron head: 450 cfm (estimated, could not locate the actual bench test results)
Used on a twin-turbo Firebird and hit 330 rwhp on a dyno. (260hp in street trim)

RHS's Gen III Ram Air head: 465 cfm (bench tested)
On their Grand Am race car with a 3400 ram air engine with 280 hp.


While the aluminum heads do offer a little better flow, Utilizing that slight increase in flow with the available intakes and cams becomes very difficult due to very limited parts available.
There are actually more parts available for the iron headed engines to maximize the power than the aluminum headed engines. (talking normally aspirated not forced induction)
GM does make an aluminum "Bow-Tie" 60* V-6 racing block which is 47 lbs lighter than the stock iron block if you are looking for weight reduction.

Personally if you are building a 60* V-6 with a carb, The iron heads would be the better choice as there isn't that much more gain (flow wise) going to aluminum heads on a normally aspirated engine.
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Happiness isn't around the corner...
Happiness IS the corner.
ZZ4 Powered !!

[This message has been edited by Oreif (edited 01-14-2010).]

I dunno man... I would have to see the specs behind those flow numbers as they look nothing like what I have seen in other resources(high)... not saying they are wrong.

Also, the RHS race prepped 3400 is at 280HP? This guy with a cam, port and polish and with a stock bottom end on a 3500 is putting out almost that much WHP out of his garage.

quote Originally posted by Oreif: While the aluminum heads do offer a little better flow, Utilizing that slight increase in flow with the available intakes and cams becomes very difficult due to very limited parts available. There are actually more parts available for the iron headed engines to maximize the power than the aluminum headed engines. (talking normally aspirated not forced induction) GM does make an aluminum "Bow-Tie" 60* V-6 racing block which is 47 lbs lighter than the stock iron block if you are looking for weight reduction. Personally if you are building a 60* V-6 with a carb, The iron heads would be the better choice as there isn't that much more gain (flow wise) going to aluminum heads on a normally aspirated engine.

Except for the iron heads being the best choice with a carb, I'm with carbon on this one Oreif.

Just as with the area under the curve for power and torque, the same goes for head flow. The total flow numbers look good however, it's the comparison in tenths of an inch lift that will tell a clearer picture. If the aluminum head is flowing at its max rate at a lower valve lift that's another plus. It's sort of like the 2L 4 cyl making 200 hp vs. the 3.5L V6 making 200 hp. Looks impressive until you find out the 2 L has to spin over 7000 rpm to get there. Of course we have no aluminum head carbuerated engine for reference so this is mostly speculation. However, I did point out earlier that the 3100 produces more power and torque than the 3.4L and that says an awful lot for an engine with .3 less litres.

Another characteristic I've noticed is that the aluminum head engines respond a lot better to boost than the iron heads particularly in stock condition. I've seen a number of documented aluminum head motors producing greater than 300 hp at the wheels on 10 psi or less.

As for more parts being available for the iron head motor, maybe once upon a time, I highly doubt it anymore. Take a look around WOT-TECH on the 60 degree forum and I believe you will change your mind. There are items pending that are not posted yet, full roller rockers, single and double roller timing chain set, etc. The multilayer steel headgaskets are available also in several different thicknesses.

For aluminum head flow numbers click on an engine size and select "heads' . The VVT 3900 and 3500 heads flow even more however they are not in as common a use yet to try and improve upon them if it is even necessary;
http://wot-tech.com/shop/35...er-heads/cat_71.html

[This message has been edited by Joseph Upson (edited 01-14-2010).]

Yeah, those flow numbers look fishy to me too. My AFR 190 small block V8 heads only flow 260cfm on the intake at 0.500" lift with a 1.6" valve.

Speaking of which, why are you locked into the V6-60 engine base? If you want carbureted simplicity, it doesn't get any more simple than a small block V8. There is TONS of aftermarket support, and it is probably cheaper than rebuilding the V6 and getting a custom intake made. Around here you can get a good running 350 for less than $1000 complete with all the accessories. Add $1000 for a basic V8Archie kit and you have most everything you need to do the swap. Electric water pump, larger radiator, etc, etc can usually be found pretty cheap used or at a swap meet.

The primary reason I've shied away from the smallblock swap is price. You get the basic kit for $1000, but there are a lot of odds and ends to get as well. I also dont really want to cut the fender on the car.

The primary reason I lean toward a 60 degree engine is, again, simplicity. It basically bolts in. If I go with the iron heads, an edelbrock intake and carb, and a distributor from an s10, it's an easy swap.

I could probably still be talked into the sbc swap, since there is so much help on this forum, though. It's hard to beat the power of a v8...

That's what I did and on a tired engine I got 132 hp at the wheels. The newly rebuilt and modified engine will be alot more.

However, I am keeping the 8.9:1 compression so I can use regular gas. I've had high compression engines before and I just don't feel I need to have one again. BTW, you might keep your eye open on Ebay for an Offenhauser intake for the carb. They are few, but do work better.

Arn

quote Originally posted by carbon: I dunno man... I would have to see the specs behind those flow numbers as they look nothing like what I have seen in other resources(high)... not saying they are wrong. Also, the RHS race prepped 3400 is at 280HP? This guy with a cam, port and polish and with a stock bottom end on a 3500 is putting out almost that much WHP out of his garage.

Typically the head flow data is shown per head, Those numbers above are the total for both heads at max lift.

The HVE 60* V-6's are an entirely different head design as they incorporate V.V.T. technology. The 3400 in a Grand Am is just a regular pushrod 60* V-6. You cannot compare a 3400 out of a Grand Am to the newer 3500 engines. The ONLY thing they share is the 60* vee of the cylinders.

[This message has been edited by Oreif (edited 01-14-2010).]