3.1 Build Plan, few questions about some parts.

[kflo 93 gt]

To start off, I've been planning an na build on my 3.1 for pretty much ever, and now I'm ready to buy parts and get busy. I've talked with Ben about it, and here's what I'm set on. 272 cam, heads worked on by Ben, full valvetrain upgrade, .030 over, 11:1 compression, ported manifolds with 60mm tb, headers, 2.5" mandrel... to keep it semi short.

First of all, I've been hunting around for pistons for awhile, and I'm thinking JBP has my answer with their Sealed Power Hypereutic pistons. I'm planning on going .030 over, and I want to run 11:1 compression. These pistons seem like a good deal, and since I'm not planning on boost, maybe just a 50 shot if I want to go over the top. Hypereutics fit the bill pretty good. I guess on this one I'm mostly wondering about JBPs customer relations lately.

They've also got "Sportman Rods" that I was wondering if anybody knew anything about. I doubt I'll get them, as I plan on having mine shot peened, or polished, with some ARP bolts. It seems like they have a lot of stuff that I've been looking around for. But knowing how JBP tends to price stuff, I'm obviously led to believe that most of it can be had elsewhere for cheaper.

Then there's also this crank, I don't know if it's anything more than a stock 3.1 crank. http://www.jbodyperformance.com/new/...catName=JP0101 But it doesn't seem like too bad of a deal for $216 for a new crank regardless.

The big plan with this engine is to rev high to work with the 272, and the high compression for the 272, and to move a lot of air in, and a lot of air out.

I've also wondered about a lot of other stuff, like phenolic spacers to keep the low end up, with the 272. But I don't really know a lot of the actual theory behind it. If it would actually hurt the top end more having longer runners, shift the power band low and do more harm than good with the cam selection. I obviously do realize the downfall is the manifolds, mine are ported pretty good. But there is room for improvement - size difference: http://kflo.berettaspeed.com/port_size.jpg
I had them done professionally, the upper and lower are port matched, and the plenum inlet is matched to my "59mm" rsm tb. I plan on getting the 60mm unit from mrzperformance, and reporting the inlet to match it.

I've also thought about making a frankentstein intake manifold too. Because the upper is going to be the bottle neck in the system. Maybe making a prototype with a larger upper plenum area above the runners, and experimenting with some veins to direct air flow potentially? I've hesitated asking about some of this stuff for awhile. But, you guys are the experts. Any comments, or advice other than swap for a 3rd gen/3rd gen parts are welcome and wanted.

[IsaacHayes]

Honeslty, if you are goign to all the work of a camp and high compression, you should look into building a hybrid. That is put 3400 heads and intakes on there. You will make more power with 3400 stuff stock than your gen2 ported stuff ever can hope to achieve.

The parts can be had cheap, and like I said even without porting you will make more power. You will have to get custom length pushrods, talk to syn about what he used perhaps.

If your crank is in good shape, leave it alone, it should be able to hold that power and then some.

I know you said no 3rd gen stuff, but listen to what you are saying, custom intake plenum? That's going to be harder than putting gen3 stuff on. I'm not saying go 3400, but put heads and intakes on. I've always wanted to build a gen2 w/gen3 top end and cam. Your motor could be very awesome if you do it right. If you want an even better plenum than the 3400 upper, put on a 3500 UIM: it has no runners (shortens the total runner length by ~3", and takes out all the curves of the runners so its a straight shot to the heads), larger plenum volume, accepts a 66mm TB without porting, and has equal flow to all ports. This means lots more high rpm power, and most everyone also says they got a big boost in low end power too with snappy throttle response. (this is just from swapping a 3400 upper to a 3500 upper). Take your $216 for a new crank and put it into a 65mm TB from this store here. Check out my 3500 swap list thread for more info on the 3500.

Seriously, do it right, make some good power. I will be jealous of your motor then. Talk to Syn about his setup.

[kflo 93 gt]

The point isn't to get the most power absolutely possible n/a. The point is to make the most power possible with 2nd gen parts.. Everybody likes to act like these engines are worthless. I love em. So yes, I do understand where you're coming from. I'm just coming from somewhere else.

[FastGT31]

if there is anyone on this board that understands what you mean by keeping it all gen2, its me. however, gen2 intake manifolds suck. i have the crane 272 cam, 62mm throttle body, JBP headers, cold air intake and various other stuff. the motor makes good power but absolutely sucks above 5500 rpm. i have heard that extrude honing both manifolds helps out considerably (i plan on doing it to my 3400 LIM when i go hybrid). what all these 660s need is a good exhaust system, headers and everything all the way back.

[SappySE107]

You should make a new lower as thats the real bottleneck, not the plenum. Both manifolds suck though so a custom plenum will mostly just screw you up unless you keep the runners the same length starting at the heads. The heads can be redone to flow very well, that isn't a problem. The intakes are the killer. Extrude hone would help but its so much money that you really would need to reevaluate your stand on using gen 2 parts when the cost is more than triple to end up with a still inferior manifold.

Going larger at those ports isn't going to help you really, as the transition from wide to tall inside the lower intake is the real restriction. Good luck getting to it though without long mandrels or cutting/welding that area so you can get in there.

[z284pwr]

JBP "Sportsman" Rods can't be much different that Crower's Sportsman 5.7" Rods that I have in my engine. Which were $371. Their catalog says part number #SP91210B-6 for the 5.7 and 211B for the 6.0" if you wanted to go with a 2.8 crank?

If you wanted a bit more wild pistons I have JE pistons in my engine I may be able to round up, a bit expensive though.....

Your crank should be fine, hell the "Unknown" mileage 3.1 Lumina crank in my engine is happy at 7,000 with no problems yet. You could always get lucky and find someone selling an LG5 Turbo crank? Thats what Curtis has in his Cavalier still I believe, no more explaination on its working....

The 272 cam specs are close to mine so it should be good. I'm assuming you are sticking with the automatic still? If so a high stall converter would fix any problems getting going if the cam loses your bottom end like it did mine.

Make sure you get good valve train components. You should be happy with it, any head porting? N/A with not nearly as much compression as 11:1 and crap tune I could easily reach 6500 with mine.

I like the 3.1 myself obviously, so of course this is going to be interesting for me to watch come along.....Well I also like the writing on my so I had no intentions of going hybird/3x00 with mine.

[IsaacHayes]

I understand wanting to stay gen2 just because or to be different. The 3100/etc doesn't have such a low end as the gen2, but with your 3spd, it still would be great over my 4t60e. The low end is still enough to break the tires free if you floor it from a stop even with the mildy geared 4t60e. The cam is what might change your torque curve the most.

If the point is most power gen2, then you should be looking at FI, as there's no real easy/realistic way to get tons of power gen2 NA.

I'm biting the bullet and switching intakes on my 3100. I'm even going with the ugly 3500 plenum over the purdy 3400 van bare UIM. But with some paths in photoshop to make a high res logo, print it up with some masking, and creative paint work, I will make this 3500 look totally rad.