The car is a 85 t/a lb9, 700r4, 3.27 bw. Right now my best is 15.0 @ 91.5 which was before hooker cat back exhaust, and a high flow cat and trans rebuild(I felt some improvement). I was thinking of putting some edelbrock headers and a set of world torquer 305's. I dont want to change my cam (I barely passed emmisions as it is) and might do a little porting on the intake. I remember seeing a mag get 266hp out of a 305tpi by tossing those heads on, should I expect that? What kind of improvements do you think I would see? What do you think for 1/4 mile times? The shop that rebult my trans offered me a great deal on a shift kit w/ a vette servo...is it worth doing?
Sorry for all the questions but if anyone can answer them you guys can.
thanks
-85

 

After carefully reading your post, and analyzing the performance vs. cost benefits of .... just put in a D*mn 350. Go to a decent junk yard, buy something with relatively low mileage, take a weekend and put it in.

 

i dont know what your talking about

world heads under $700 shipped
edelbrock headers $390 (id need anyway)
shift kit $200 (also wouldnt hurt)
gaskets, mis. $150

I dont know what the 350 from a junkyard costs but did I not make myself clear about EMMISIONS!!
anyone else with a more open mind out there?
thanks


[This message has been edited by 85transamtpi (edited October 24, 2001).]

 

lol, TPI guy makes me laugh. I really hope he does this as a joke, as it ain't the first time i saw him just straight up tell someone to just swap to a 350. He just don't know about the 305 TPI's mad revs, lol.
Anyhow, in a way he is right. You would be insane to dump $700 on barely better than stock heads for that 305. It would not be worth it. If naything, run the L98 aluminums. They're still not great, but they'll beat the 305 torqquers and have more potential when ported. If you don't plan on running faster than 13 flat/high 12s, L98 aluminums will be fine just fine.

I think the bigger issue before any of this is what is wrong with your car now. You're saying it barely passes emmisions now as is. Thats a sign that something is wrong with it. With a functioning cat and the negine in good running order you should be clean. If your basics aren't right, don't even start getting into modding, you'll get nowhere fast.

 

My car runs fine and all emmisions control systems are working. My emmisions here in Illinios get harder to pass every year (no joke) and I wouldnt want to end up with something that had no chance of passing. Ed, wouldnt L98 heads drop my compression a lot? How much would they have to be milled down to keep my stock compression? Would I have problems with valve shrouding? To me vette 58cc heads make much more sense, but I havent been able to find a pair, and I beleive that the bolt holes need to be drilled out to fit. And no one has been able to answer my original question...what will it run?
thanks

 

Yes, your static compression will be the same because both 305and aluminum L-98 heads share a 58cc chamber, but your effective compression ratio will be about a point lower than whatever it is currently due to the heat dissapation properties of aluminum.

Valve shrouding isn't really a problem in that it won't cause your engine not to function. I believe that the SR torquers have a 1.94 valve also, so you will have the shrouding issues with any aftermarket head.

You will pay $400 for a set of used L-98's, $200 bucks to check them out and clean them up. If they mill them, they will probably have to be angle milled to avoid intake manifold alignment issues $$$. To have them ported is something like $600 by a good porting guy ... what will you want your combustion chamber size be?

Let's do some math:
What you want to do is find the maximum volume of air that can occupy the cylinder. (make sure your units are the same ... convert inches to cm)

((Bore Diameter/2)^2 x pi x stroke) + (gasket thickness x pi x (radius of gasket bore)^2) + Combustion chamber volume
= maximum cylinder volume

You will be compressing this total volume into the head gasket and combustion chamber volume.

CR= Maximum cylinder volume/(combustion chamber volume + head gasket volume)

Some things you'll have to look up are deck height, the presence of piston valve reliefs, current head gasket compressed thickness. If you want to use the same head gasket, and both heads have 58cc chambers, you can just subtract 1 from the number GM publishes for the iron heads. You could also use the formulas listed above to work backwards through the calculation, along with some of the aforementioned data, to find out what you need to know.

One point that I would like to bring up is one common misconception about compression ratios:

Theoretical compression ratios are calculated assuming 100% VE. We assume that cylinders are completely filled before combustion. This is false. Really false. Engine rarely operate at 100% VE.

When guys write in to magazines and say, "I have 11:1 compression on a set of old smogger truck heads, and there is no detonation on 87 octane" They can do this because, in reality, they might be operating at 60% VE. The theoretical CR may very well be 11:1, except their truck heads aren't allowing for complete filling of the cylinder, so their effective ratio is really more like 8:1 or 9:1.

 

Thanks for the info
I thought the L98 heads had 64cc combustion chambers. These would probably work well for me then. I am not looking to run 12's or even 13's. The car is my daily driver so Im just looking for mid to low 14's. Does anyone sell these heads reconditioned and assembeled? My local machine shop said a three angle job runs about $200, and I would probably need some new springs. Do you think I could run to a junk yard and pick these up or are they hard to find? Also is the shift kit worth doing? Also, do I need an external EGR setup with these heads to pass emmisions?
thanks all
P.S. I have a 85 block...arent the 86+ heads different?
[This message has been edited by 85transamtpi (edited October 25, 2001).]

[This message has been edited by 85transamtpi (edited October 25, 2001).]

 

Cast Iron L98's have 64cc chambers, Aluminum have 58cc's. If you have an 85 engine, your manifold will need the bolt holes elongated to work with the 87+ heads. I have no idea how difficult it would be to find these heads. If you check the classifieds here, you will probably find some there...

 

If you can't get into the mid/low 14s on the stock unopened longblock, there's something wrong with your car. Stock heads are more than capable of getting you into the high 13s w/ even a basic combo.
Seriously, if thats your goal, save the $$$ you were planning on using for heads and get SLP headers and a decent converter. With everything running correctly those alone should get you into the low 14s. Port the intake up nice and you're in even better shape. PROM tuning never hurt anybody either.
I say again though, if you are having problems passing emmissions, something is wrong with your car, no two ways about it. Plenty of cammed, headed, fire-breathing monsters have no problem passing emmisions. The key is having everything running optimally.

 

I am not having problems passing. I failed before with a gutted cat. I put on a Walker high flow cat and passed with no problems. What I meant to say was that the car needs to be completely emmsions legal because it is my only car/daily driver. (I cant just dump a 350 in there and hope it'll pass the 305 emmisions) I thought those heads needed modification which is why I would want to go with the Worlds. Im pretty sure the L98 alum. heads need external EGR also. It just seems stupid to me to not change the heads becuase I know mine are getting old, and it would be almost as much money to have those rebuilt.
So back to my original question....what do ya'll think it will run with World torquer 305's, Edelbrock headers (My buddy had problems with SLP), and the shift kit?
thanks

 

Stock longblock LB9 in the 13's Ed? I hope you don't mean stock untouched longblock. You'd need a hell of a port job to make 13's out of an LB9, not to mention high stall and gears. (cam to match)

------------------
-Jason M. 1991 Camaro Z28

 

Maybe I was unclear with the topic "what do you think I'd run?" because not one person has been able to give me a guess. Does anyone have this setup or something close?

 

I dont know what you would run but I am woundering what your 60ft times are like and what abought your reaction time you may be better off spending some cash on traction if you are worried abought the smog test. And just so you know I just bought a 350 out of 89 vet 40000 moiles on it for 900 at the salvige yard and abought 50 in seals other then that just time spent to put it in the car I put it in a 84 camarro for a freind so you may want to look in to that for more engine power and the smog test shouldnt be a problem if you keep it stock and you will have I think 250 + horses they are rated from the factory.But other wise I would look in to Lower control arms panhard bar and torque arm and mabe a set of bfgoodrich drag radial tires and try to nock some time off that way when it comes to time slips thier is more to work with then the engine and most of us should probably start with are 60 ft times.

 

NOBODY KNOW WHAT YOU WILL RUN.... weve seen modded 305 TPI's run anywhere from high 15's to high 13's!!!!