quote Originally posted by unboundmo: Also... I'm curious... aren't your side panel scoops functional?.. the reason I ask is that I have modded side scoops (both sides of the car) and I mounted a B&M oil cooler with a temperature controlled fan sitting on the passenger side under the battery box in the well area. 8x8 x1-1/2 with fan inches deep, I think. fit like a glove with some little space left over.. the oil filter may fit as well... it works so well!.. why the trunk?.. I had to fab a bracket but no big deal..

I agree, the side scoops are perfect places to put an oil cooler. And if your battery is relocated up front, it opens up a perfect place for an oil cooler or intercooler, as well.

That said, I'm interested in seeing how Rei decides to mount his oil cooler.

quote Originally posted by Blacktree: I agree, the side scoops are perfect places to put an oil cooler. And if your battery is relocated up front, it opens up a perfect place for an oil cooler or intercooler, as well. That said, I'm interested in seeing how Rei decides to mount his oil cooler.

Well I'm saving the side scoops for something else but the oil cooler will be replaced with a bigger unit that will have its own fan. The trunk part will be an open space and a rear diffuser will take its place.
I'm working on making the entire underside of the car flat bottomed. And the side scoops along with two big NACA ducts in the under plate will be responsible for bringing cool air to the engine compartment.

I wanted to share my cooler just for kicks.....



I get the oil from a sandwich I bought from, I think, Paul's Plumbing.. It's billet aluminum.. I have a large viton o-ring on the block side including a bushing threaded spacer that came with it



Some naked pics.... :| ... And with a homemade bracket to hold it in place..





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.....and then,what i like to call...., the black hole :0 ... Lol




With the wheel well installed, it creates an excellent cavity to cup that air.

--->

Some fan faqs------

The cooler's fan turns on at 185 and shuts off at 175, keeping it at a good optimum temperature I think... The fan even continues cooling for 30 seconds after the car turns off..

[This message has been edited by unboundmo (edited 11-30-2017).]

quote Originally posted by unboundmo: .....and then,what i like to call...., the black hole :0 ... Lol

That's awesome!

quote Originally posted by unboundmo:

Where did you get these from and how much were they?

quote Originally posted by mender: Where did you get these from and how much were they?

I actually made them.. sorry.... and they were FREE!.... we'll sort of.. minus my time and fiberglass stuff on top of the original starter panel scoops-- cost way back..around- a little under $400with shipping, I think. -- they're not available to buy anymore that I know of.. at least as a production run. I think the original molds are in Germany somewhere.. before that, was Australia --- AUS Stage II Scoops)

There was a lot of fab work for me.. originally, I had the stage II scoops .. then due to friends having them also, but with the door trim that went with it as a kit.. I wanted to go into a different direction to be original. I refiberglassed the mold to follow the lines of the original GT trim..... then made the scoops to insert..

I don't want to jack this thread though..

I'm really interested in La Fiera's 3.4L hittin 250hp!

[This message has been edited by unboundmo (edited 12-01-2017).]

If I remember right mine is a Mr Gasket adapter. It works pretty good!

quote If I remember right mine is a Mr Gasket adapter. It works pretty good!

Right!...I saw this a couple pages back.. clean😎... gave me some ideas.. (hope you don't mind).. seriously though; I was like, duh!... I love how everything is just up, out of the way.. especially if I ever get to my dreams..... a belt driven/mounted in the A/C area Supercharger 😜

Nice and hidden from the top side..

[This message has been edited by unboundmo (edited 12-01-2017).]

quote Originally posted by unboundmo: Right!...I saw this a couple pages back.. clean😎... gave me some ideas.. (hope you don't mind).. seriously though; I was like, duh!... I love how everything is just up, out of the way.. especially if I ever get to my dreams..... a belt driven/mounted in the A/C area Supercharger 😜 Nice and hidden from the top side..

What engine you got in your car? It looks pretty clean and like mine everything is wrapped on heat shield!

quote Originally posted by La fiera: What engine you got in your car? It looks pretty clean and like mine everything is wrapped on heat shield!

The 88's were pretty well equipted with shields and wraps.. I've re wrapped the harness when I had the engine out once before... although, around the exhaust piping (topside), the 88 came with this NASA molded/spot weld/ ugly thing.. I changed it out to have the 87 heat shields. I don't have the blower, though, for the coil so I've taken other percautions to help with that. The lower shield under the firewall side exhaust manifold is stock 88... ...and I "have" to say it's a 2.8L... Cali laws 😏

quote Originally posted by unboundmo: ...and I "have" to say it's a 2.8L... Cali laws 😏

Nothing wrong with the 2.8. I don't know if yo know but before my 3.4 I had a wicked 2.8. Check this out:

https://youtu.be/dayXz0arXZ0

In action

https://youtu.be/apPx7Tu3Q9E?t=4m47s

[This message has been edited by La fiera (edited 12-02-2017).]

quote Originally posted by La fiera: Nothing wrong with the 2.8. I don't know if yo know but before my 3.4 I had a wicked 2.8. Check this out: https://youtu.be/dayXz0arXZ0 In action https://youtu.be/apPx7Tu3Q9E?t=4m47s

I really like the crackle sounds..especially in the supernatural video.. the warm up... were you running a muffler at the time?.. and is it with a catalytic?

Definitely cammed!.. is that a 272 or 260 range? Did you have the full roller rockers too like I saw on the 3.4L?.. interchangeable to both engines of course... curious if the 272 lift was able to mesh with the 1.6 ratio?.. if that's what you have.. I've read that it's too extreme).. I like the 1.6L with the 260 myself.......

What fuel pump are you running?.. mine just went out--AGAIN.. number 2 from Walbro-junk 255. Does yours not reach the full pressure on the 1st turn of the key?.. speaking the supernatural video.. I noticed you turned off and on again the switch

.... you stripped your interior for weight also.. I wonder what the technical weight difference is?....

I love our cars.. cool little racecar for its class.... and yes, this is my go-cart too 😬... just sayin

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So what's next in your plans with this 3.4L??.... and the rest of the car

[This message has been edited by unboundmo (edited 12-03-2017).]

The 260 and 272 cams are smaller than the one my 2.8. The 260 is 204int/216ext duration @.050 and the 272 is 216int/228ext duration @ .050.
The cam on my was 230 @ .050 with .512 lift on 1.6 roller tip rockers. But the heads on the 2.8 as well as the 3.4 are machined to take adventage of the plethora of valve springs of the Small Block Chevy. You must use good springs with big cams

[This message has been edited by La fiera (edited 12-03-2017).]

quote Originally posted by La fiera: I was using the stock fuel pump and noticed it had a hard time keeping up with the AFR so I upgraded to a 340GLH. After installment I had to re adjust the fuel pressure. Now the gauge on the regulator is steady, before it was bouncing up and down and the AFR's are steady.

Did someone check the pressure during a WOT run on a dyno?

quote Originally posted by pmbrunelle: Did someone check the pressure during a WOT run on a dyno?

The dyno runs were very erratic without any changes on the software. I could keep my eyes glued to the AFRs and it would oscillate way out of proportion. And yes, I also had someone look at the fuel pressure regulator gauge and he said it bounced so bad he couldn't keep up with it. After the pump was replaced the AFR's and gauge pressure are steady. I don't take chances when I'm on the dyno so I always run dynos on 112 octane in case something goes wrong. I didn't do that with the previous build and it twisted a rod. After that I always run 112. After everything checks out good then I go to 93 octane. My compression is 10.8:1

[This message has been edited by La fiera (edited 12-03-2017).]

quote Originally posted by La fiera: The dyno runs were very erratic without any changes on the software. I could keep my eyes glued to the AFRs and it would oscillate way out of proportion. And yes, I also had someone look at the fuel pressure regulator gauge and he said it bounced so bad he couldn't keep up with it. After the pump was replaced the AFR's and gauge pressure are steady. I don't take chances when I'm on the dyno so I always run dynos on 112 octane in case something goes wrong. I didn't do that with the previous build and it twisted a rod. After that I always run 112. After everything checks out good then I go to 93 octane. My compression is 10.8:1

Am I wrong that when talking about octane ---- 87 - 112.... the higher the number, the more delayed in explosion?... not sure if my Dad was right but he always said the higher, the more junk is in the gas to delay the explosion.... so it would be a timing thing to fine tune a certain octane to a certain timing for maximum efficiency?... higher octane, the less advance the timing?

I run 91 with my built Fiero - set at 10*.. but I use 87 for my stock jEEP.. stock ecm setting.. whatever that is

****Can someone explain this?---- no guessing!****

https://www.bellperformance...oline-Octane-Ratings

Octane explained

quote Originally posted by unboundmo: Am I wrong that when talking about octane ---- 87 - 112.... the higher the number, the more delayed in explosion?... not sure if my Dad was right but he always said the higher, the more junk is in the gas to delay the explosion.... so it would be a timing thing to fine tune a certain octane to a certain timing for maximum efficiency?... higher octane, the less advance the timing? I run 91 with my built Fiero - set at 10*.. but I use 87 for my stock jEEP.. stock ecm setting.. whatever that is ****Can someone explain this?---- no guessing!****

Higher octane doesn't change the burn speed, it raises the fuel's auto-ignition point. That means it takes more temp/pressure to light off the mixture without an outside source (spark usually).

Proper timing is set for the engine's characteristics, not the fuel's. Run what the engine wants, both in timing and octane.

I see SBC rods in your future.

Did you blow the motor already? How many miles you get out of it?

quote Originally posted by Daryl M: https://www.bellperformance...oline-Octane-Ratings Octane explained

This is great.. thanks Daryl.. and mender

----does anyone know if there is a guide / chart somewhere that shows what compression is for what range of octane?.. sorry La Fiera for interrupting your thread... some good advise though!

Anyway, My Fiero is running 9.25:1 compression -- Ross pistons

Edit to say----- I guess my Dad had it right, in a way.. I was wrong when I started talking about timing..

[This message has been edited by unboundmo (edited 12-04-2017).]

quote Originally posted by turbo 3800: Did you blow the motor already? How many miles you get out of it?

No, the first time It bent a rod and I was just driving it normal. I checked the timing table and it was way too advance I made sure I checked everyting and the timing I sincerely forgot!
When I got home I can hear the rod noise! Not even 50 miles
So I took it out and put new rods and crank. Also re adjusted the timing table and is all good now.

quote Originally posted by unboundmo: 112 octane with this chart is way up there in compression.. just a little overkill?.. where does one even purchase the additive to make it that octane? ..... >---rocket fuel-----> Per the chart and your compression.. I don't see any less than 100 octane to be safe?.. no knocking.. not sure if 93 will be okay?

I built an iron head 4.3 with 9.9:1 compression and a stock cam (very mild) for my Astro that I ran on 87 octane all the time. It doesn't hurt that I'm at 3000 feet altitude but no problem down at sea level either.

It depends on the engine. With good prep and good combustion chamber design etc 11:1 is doable, whereas with a poor design (my old '54 Chev 235 for example) the max compression on 87 would be around 9:1.

It gets pretty involved when exploring the fringes and the consequences can be dire, so run a bit more octane than you think it needs until you've thoroughly tested your combo.

[This message has been edited by mender (edited 12-05-2017).]

quote Originally posted by La fiera:

So quick question...---- I guess I've been the question guy lately😐.. Hey!-- bump to the top!

Anyway, what size primaries did you go with here?...... I thought I read somewhere that you were working on them at the time? Are these the new? For the other Y-section picture you posted, that was the old? I can't quite figure how that fits to this header?... long headers a ***** on the firewall side I bet?

and the 3to1 collector.. is that a 2-1/2" out?... after this section, did you route the same as stock for the rest of the pipe?...

any pictures ? ..... what muffler is that in the supernatural vid?.. might as well ask that one too... just get it out of the way --- hollowed out goodness to my ears..... I'm getting to think that mine is too mellow now.. but not like I'll atempt to make another system anytime soon.

quote Originally posted by unboundmo: So quick question...---- I guess I've been the question guy lately😐.. Hey!-- bump to the top! Anyway, what size primaries did you go with here?...... I thought I read somewhere that you were working on them at the time? Are these the new? For the other Y-section picture you posted, that was the old? I can't quite figure how that fits to this header?... long headers a ***** on the firewall side I bet? and the 3to1 collector.. is that a 2-1/2" out?... after this section, did you route the same as stock for the rest of the pipe?... any pictures ? ..... what muffler is that in the supernatural vid?.. might as well ask that one too... just get it out of the way --- hollowed out goodness to my ears..... I'm getting to think that mine is too mellow now.. but not like I'll atempt to make another system anytime soon.

Primaries are 1.5 inches, collectors are 2.24 inches go down to meet a 3 inch pipe, no muffler.


This shot is so you can see the Y pipe installed. Its pretty far from the distributor to avoid cooking the ICM. Also if you look at the header on the trunk side you'll see it covered by a shield, I have the same shield on the firewall and I still have plenty of space from the firewall.


It also gives me plenty of space to work around the trans cables and transmission. The clutch hydraulic cylinder is below it with plenty of clearance. I can take the cylinder very easy with the Y pipe in place


Here is the exit, a 3 inch pipe oval at the tip.

I never had any problems with it, my only complaint is that is a bit heavy because the gauge of the steel is thick.
I have the colletors that attach to the Y pipe on a bracket bolted to the transmission that way the headers don't hold the weight of the Y pipe.
The 3 inch pipe that serves as the final piece is also attached to the engine at the head, no exhaust part is held at the chassis. "If" the engine moves the entire exhaust system moves with it. The next Y pipe will be similar but it will be exiting on the drivers side made out of thin chromoly steel, so it'll be shorter and much lighter.

It is my understanding that changes in valve and ignition timing can allow for lower octane fuel to be used. It isn't just compression ratio that determines the octane requirements. Is this correct?

quote Originally posted by Daryl M: It is my understanding that changes in valve and ignition timing can allow for lower octane fuel to be used. It isn't just compression ratio that determines the octane requirements. Is this correct?

You are right. With a motor that has a lot of compression you can install a large camshaft and it will bleed off a bunch of compression and at the same time you can retard the timing to run lower octane with a high compression motor. I use those compression vs octane charts just for reference.

quote Originally posted by Daryl M: It is my understanding that changes in valve and ignition timing can allow for lower octane fuel to be used. It isn't just compression ratio that determines the octane requirements. Is this correct?

Correct. To be more specific, the engine runs on dynamic compression. Dynamic compression is basically the static compression modified by the valve timing. So for example, a camshaft with lots of duration will reduce the dynamic compression significantly. This is why it's recommended to increase the static compression with a high-performance camshaft. Because you don't want the dynamic compression to get too low.

As a general rule, more dynamic compression requires a higher octane rating. And vice versa. Although cylinder head design can affect this, as well. For example, aluminum cylinder heads tend to run cooler than iron heads. So you can use a little more compression, or a lower octane rating, or a combination of the two.

[edit to replace the word "overlap" with "duration"]

[This message has been edited by Blacktree (edited 12-11-2017).]

Well... it's actually a late intake valve closing event that modifies dynamic compression. That has nothing to do with overlap.

Either you misunderstood what I said, or you're trolling... not sure which.

quote Originally posted by Blacktree: Either you misunderstood what I said, or you're trolling... not sure which.

More like you misunderstood dynamic compression.

See the Atkinson cycle.