Project 91 "SS" 3400/5spd

[3X00-Modified]

We run the GM 350/355 sealed race crate engine in the race car, its a decent peice... it stays together, starts every time, and has only needed spark plugs and oil the whole year... Normally we would have done at least 3 sets of valve springs by now on the open rules motors, Puts down 293hp to the wheels with a 3 speed sagnaw and 10 bolt. I think it was 335hp and 396tq on the engine dyno with the 4 barrel carb. Just recently they made us go back to a 600 2 barrel and we lost 16hp and 6ftlbs... all because they think the crates are too fast, yet we are the only ones with one so they have no "control" to compare to.

[woody90gtz]

Crate 350s aren't bad engines, I just take pride in coming up with my own combination and building it myself.

I did a Desktop Dyno simulation with the stock Vortec cylinder head flow data, my cam timing & compression, etc and it came up with 417hp, 430lb of torque. It would be cool to put mine on an engine dyno and figure out exactly what it put out. I was all excited to chassis dyno the Camaro at Bfest this year until I actually thought about the 13-hour drive in that thing with no cruise, no stereo, no ac, no wipers, drag radials... haha

Since I just bought a 94 truck, I'm toying around with the idea of using the 4-bolt roller cam truck block with a 294/302/600/106 solid roller, AFR Eliminator 195 heads, 11.5:1 forged pistons and a forged Scat 383 crank for 500+hp NA and the ability to run a 300 shot ZEX plate... Then I can use my Camaro's 350 with the truck cam & intake with Vortec heads for some extra towing power for the Z71.

But I am crazy.

[Money pit Beretta]

Well 3X00, I guess they won't let you put a spacer on there or you would have done it.

Dang Woody, you are crazy to do that to the truck. I will say that you should take pride in what you have done. Check into those Fast Burn heads. I'm not sure if they are good for a race set up, but they are great street heads. I'm a freak for a good clean burn, so that's why I like them. I was one of the first 20 to order the Trick Flow heads by the way(my name was on a list in Hot Rod magazine). I gave up on them to use the money to get some cheaper heads and get my engine built sooner(bad idea, they were something like 750 bucks at the time). They were back ordered for a long time and I held out as long as I could. Lost my car after that and never got a chance to buy them at that price again.

[woody90gtz]

I think you got the wrong impression. I'd swap the rebuilt truck engine into the Camaro and tame down the Camaro engine for the truck. The aluminum "fast burn" heads are very similar to the Vortec 062 heads that I have. The Vortecs flow marginally better and make better torque (being a truck head), but they are a lot heaver since they are iron. The best cylinder heads on the market hands down are the AFR Eliminators, street or strip. It is absolutely ridiculous the power you can make with those. They put Trick Flow, Edelbrock, Canfied and all the others to shame.

[3X00-Modified]

Well 3X00, I guess they won't let you put a spacer on there or you would have done it.

There's a spacer on it, there always has been. Still going from a 4 barrel 600cfm carb to a 2 barrel 600cfm carb your bound to loose top end power and we did.

[Money pit Beretta]

Miles off topic.... AFR, I remember when they were new also. Sounds like the only good thing about the Fast Burn heads is how the chambers are set up, that and you can run on cheaper gas. I always wanted a 383(or a 377). I wish I could stroke the 3400 I want to build.

3X00, can you put one of those plastic velocity stacks on? They(Mr Gasket) use to make them for Holley 2bbl's and it would help the air flow into the choke horn. That is if it would match up to the lower part of your air cleaner and if it's legal. It looked like this one, just had only one hole. http://www.jegs.com/webapp/wcs/stores/s ... +stack&N=0
Looks like I was wrong, it's a K&N stub stack #85-0210. I have looked, but all that comes up is a photo of the 4bbl one and says that is for the 2300 Holley 2bbl.

[3X00-Modified]

Velocity stack vs spacer is a different thing.

We are already at the limit of every rule in our book, trust me Never illegal though, always in that gray area 3 time division champions speaks for itself. 04 06 09

[woody90gtz]

Miles off topic.... AFR, I remember when they were new also. Sounds like the only good thing about the Fast Burn heads is how the chambers are set up, that and you can run on cheaper gas. I always wanted a 383(or a 377). I wish I could stroke the 3400 I want to build.

Most cylinder heads have the same basic chamber design since it is far superior to the old school stuff. I think AFRs are even better than the fast-burns as far as resistance to detonation is concerned. I know there are guys on NastyZ28 running close to 12:1 on 93 octane with the AFRs because they need so little timing for peak power and you can run a huge cam reliably because the valves & springs are so light. It's one of the reasons I'd like to can my current 10.5:1 Vortec setup. I'd lose little streetability and gain ~100hp.

Even 3X00 heads have a similar chamber design to fast-burns. Technology has come a long way since the used-to-be-holy-grail "camel hump" #447 SBC heads.

[Money pit Beretta]

Rollers are much better on the street Woody. I know a guy with 535hp/tq at the rear wheels with a roller and it acts like it's stock until he gets on it. Glad to know that the 3400 heads are so good. Oh and I almost had a set of those double hump heads a long time ago(they weren't tapped for accesories though).

I should have known that you would have all the stops pulled out on that thing 3X00. Well, that stub stack is something most people don't know about though. Too bad you can't use it.

[IsaacHayes]

(Refering to 60V6) Yeah even the gen2 heads are fast burn... The gen1 iron heads used a ton of timing (not fast burn), gen2, less timing, and gen3 even less timing because they burn so fast. Too much timing even if you don't get spark knock will hurt performance past a certain extent as the pistons has to fight the flame front while it's still moving upwards. The aluminum heads have heart shaped combustion chambers promote swirl and aid in quench with the flat spots. The gen3 motors got better heads due to the intake/etc ports (look at 3500 gen3.5 stuff) and way better intake manifolds than the gen2 crap.

Flat top pistons with .040 quench and high compression with a healthy cam (decent duration and/or overlap) to help bleed off the static compression would be really sweet on a 60V6. Hell, there is someone with a 3400 with over 12.something compression with a cam on pump gas. And I believe that is with the camaro pistons not custom, so the quench is far from ideal (.070). Larger than ideal quench reduces power some, and also makes it harder to prevent pre-ignition. It probably is possible with ideal quench and a big cam to run 13:1 compression on pump gas. The actual compression after you figure in the intake closing events from a cam is called dynamic compression which is a bit miss-leading because it doesn't change unless you consider changing the cam specs then that holds true, as it will vary then. Actual compression is a better term. IIRC with the stock (weak) cam a gen3 actually works out to about 9:1 compression. So it bleeds off .6-.8 or so of the compression.

I wonder what SuperDave's IVC ABDC (intake valve close at bottom dead center) degree is... he has a rowdy cam... I could figure out what compression he could run and still be compatible with pump gas... With his power he is putting to the wheels more compression would really make that motor a beast.... Custom pistons would be the only way since it's a 3500 though and no other motor in that bore has pistons that drop right in (like you would put iron head 3.4 pistons or DOHC 3.4 pistons in a 3400), but that means you could order them with the right deck height to get .040 quench which is good. I wouldn't try for .35 as that's too close for comfort if you ask me with high RPMs... Flat tops with valve relief would be best since the flat top would help with the quench effect more than dished pistons, and the valve relief would help prevent kissing the valves from spring float and rod stretch at high RPMs.

If you really want to get extreme and run as high of compression as possible on pump gas, you could push it even higher with ceramic coating the piston tops, and combustion chambers to reflect/insulate heat. Also coating the intake ports would help insulate the intake charge...

[Money pit Beretta]

Oh man, what great info Isaac! I'm also a freak for a good quench(or you could call it burn). Man I need a good job. I would love to get started on the build(still looking for a job). Looks like we did it again. Woody, how is the SS doing?

[woody90gtz]

Actually I was thinking about a pair of 3500 heads, but without changing pistons or milling the heads you cant get good compression and quench... so I'm just leaving it as is with the stock 3400 heads. No need to go crazy with the Beretta, because it still wont be my fast car... no matter what I do.

Quench is very important. By getting it just right you can run more compression and be the most efficient. Stock 350s (at least in 2nd-gen Camaros) have the pistons .024 in the hole. So I went with a .015 head gasket instead of the normal .039, for 10.5:1 and .039 quench, instead of ~10.0:1 and .063. Both are at the bordlerline with detonation on 93 with my moderate cam and iron Vortecs.

Isaac is exactly right about dynamic compression. That's why I'd like to run a huge solid roller and 11.5:1 compression in my next engine build. Although I do have a hard time believing a stock 60*v6 could have a dynamic compression ratio of 9:1 and still run on 87 octane. From what I understand, anything above 8.5:1 dynamic compression is pushing the limits of detonation with 93 octane. The dynamic compression of my Camaro is 8.3:1 and will not run on anything less than premium.

Does anyone have the stock cam specs for an LA1? And the stock compression ratio is 9.5:1, correct?

[99GaGT3X00]

heres the stock cam specs same infro with some more info in this page too http://www.60degreev6.com/Stock_Camshafts

* Cam Lift (Exhaust):.272"
* Cam Lift (Intake):.272"
* Cam Timing at .050" Lobe Lift (Exhaust Close):12 Deg BTC
* Cam Timing at .050" Lobe Lift (Exhaust Open):32 Deg ABC
* Cam Timing at .050" Lobe Lift (Intake Close):29 Deg BBC
* Cam Timing at .050" Lobe Lift (Intake Open):15 Deg ATC
* Degrees Overlap:39 Deg
* Duration at .050" Lobe Lift (Exhaust):197 Deg
* Duration at .050" Lobe Lift (Intake):197 Deg
* Lobe Centerline (Exhaust):111 Deg
* Lobe Centerline (Intake):113 Deg
* Valve Lash (Exhaust):Hyd.
* Valve Lash (Intake):Hyd.
* Valve Lift (Exhaust):.436"
* Valve Lift (Intake):.436"

Jon has been running 89 the whole time i beleive, from when we were talking at albany he has a highly modified spark table too.
now that my car runs fine and i got a tweaked but not outrageous spark table in there , im still not seeing any knock and my spark is far from stock. im still running on 89 too.

with the 3500 heads it drops the CR down to about 9.1.1 iirc.

what ive been toying around with since i bought the cam a few years ago was to go with a high CR setup. with the 3500 heads, rwd 3.4 camaro pistons and either the stock head gaskets or camaro head gaskets ( cant remember right now) i would end up with a 11.5.1 CR. already have the pistons but not too motivated to tear apart the engine again. i just fixed resealed the valleys this week so it wont seep oil anymore, been putting that off all summer.

[Cliff8928]

Actually I was thinking about a pair of 3500 heads, but without changing pistons or milling the heads you cant get good compression and quench... so I'm just leaving it as is with the stock 3400 heads.

Not even with the new MLS gaskets?

[IsaacHayes]

Don't forget aluminum heads help you out over iron......

Stock 3400 compression is 9.6(9.64). 3500 is 9.79. IVC ABDC is 29* as mentioned above.
3400 works out to 9.13:1 dynamic with .040 stock quench.
3500 works out to 9.27:1 dynamic with .050 stock quench.

You can go with MLS headgaskets at .030 and 3.4 gen1 iron head pistons for .040 quench (stock gasket is .040 and .050 quench on iron head) but then you end up with 12.73:1 static compression with 3500 heads. If you run .060 3500 head gaskets you end up with 11.5:1 and .070 quench. The 3.4 DOHC had .070 quench stock believe it or not at 8.81:1 static compression. If you use the pistons from that you'll have even higher compression.

Looking at superdave's cam specs his IVC event is a whopping 69.9*. That means he could run 12.4:1 static compression to end up with the stock dynamic compression of the 3500!!

I know 93 octane is possible to run 11.5:1 with poor .070 quench with 33* IVC event. That is 10.75:1 dynamic. And I'll be running that on 91 octane come spring. I may have to run a colder plug though.



The stock pistons are a dish. If you go with flat tops (with valve reliefs for the valves) that will aid in quench even more. There isn't much quench with the stock pistons anyway, because only a small ring around the outside is actually flat. The rest is a concave dish...