LT1 heads...how much hp?

[sothpaw]

This is a cliche topic, but we are in the mods section (my favorite!!):

If I had my LT1 heads ported& polished or purchased stageII heads, and put a 52 mm TB on the car, and threw in an Ed Wright chip for good measure (I'd give him the specs--I can't program with the '93 without some significant equipment), what would be the gain?

--I saw numbers in a book once that said about 27 hp (fly) for the heads and 12 more for the TB.

--My delima is that I want to add 30-40 hp and get solidly in the 12 s, but supercharging is more efficent for cost and easier to tune...

 

[Mad-Mic]

sothpaw,

depending on what kind of head work you want done. if you want the full effect of cfm movement could cost as much as 2000 dollars just for the work itself but with a HiPo cam and a good intake manifold you could net upto 100+ extra ponies. porting and polishing is one thing that helps alot and thats probably a good 20 there alone but i'm not sure what valve size is in the LT1 motor you can eventually get it hogged out to a 2.08 intake 1.60 exhaust or a 2.05 intake and 1.65 exhaust. this would yield ALOT more HP compared to a 1.95 intake and 1.52 exhaust more air in more air out = more overall HP. some cam companies like lunati, crane, and edlebrock advertise upto 150+ ponies with their cam heads and intakes (but their intakes are for carbs not tpi) your probably looking at around 3000 dollars for all that less intake but would cover costs of porting and polishing of the intake. only thing left to do would be lower end for another 1500 you could have one stout motor! for a few more bucks you could get a nice steel 400 crank meat out the block and make it a 383 stroker

i got an LT1 motor for sale if anyone interested came out of an SS imp that was running high 13's new eldebrock heads and a bunch of new stuff car was totalled. seller told me 3000 for motor and trans (2 bolt main LT1 motor 460LE trans) i think i could steal it for 1500 at most but i need an LT1 car first :L

 

[Vettelt193]

with the stock cam, heads won't be worth the cost... If you do a cam and heads, you will be running a setup close to what UB2SLOW has.... a good setup, but a setup that is happy at very high RPM, too high for me to feel comfortable with a stock LT1 bottom end.... you also have to look at how the car is setup... have you thought about nitrous? it won't take a big hit of nitros to get you into the 12's solid, and NOS is basically the same as a supercharger, just much cheaper

 

[sothpaw]

bottom end

Vettelt193,

Forgive the ignorance: You mean bottom end of the engine, pistons, etc? Not transmission and diff.

Yes, I thought of Nitrous for this, I just have fear/dislike of it,
in that I heard it's really easy to blow the engine with nitrous, also you can blow up yourself. I'd only use it as a last resort.

Am I correct in thinking that the LT4 Hot cam alone wouldn't help too much as I already have roller rockers? To get 30-40 hp I should really do heads and cam or go some other route all together?

 

[Vettelt193]

the LT4 hotcam is made to work with the full 1.6 rollers, it will definitely help... just realize the LT4 hotcam is a high rpm cam... when i talk about the bottom end falling apart... the crankshaft, rods, etc.... these were not really built to run at super high rpm (BTW, this is why the LT4 has a different crankshaft) I am not saying you won't gain a good amount of HP with a good set of heads with no cam, but to really take advantage of the heads, a new cam is really necessary... a great set of heads without a good cam will give your engine every ability to take in air, but the engine won't be setup to take as much air in as it can, so you will waste some of the flow of the heads.

At this point you need to come up with a couple basic ideas.... first off, budget (which may be variable with HP gains)... second, do you want an engine with High HP at High RPM, or an engine that has a more broad power range?

on top of all this, NOS isn't unsafe like it used to be.... it would be setup with a full throttle switch, plus an engage switch... you can even get variable NOS now, so it acts just like a supercharger... basically, it slowly engages with RPM, instead of one big hit.... IMHO, the only real benefit a supercharger has over nitros is it never runs out.

 

[wookiebear]

Southpaw and the Feart Of Nitrous!

Southpaw,
I have a Nitrous set up and I could not be happier, there are alot of horror stories out there about N2O and it is generally from people doing very very stupid things like reving the engine in neutral and hitting the N2O button etc. When set up properly N2O will give you the best bang for the buck over any modification. Engine failure results from Lean Out of the engine while under N2O if you install or have professionally installed a system that has rev limiters along with the high speed fuel pump you will not have a problem. My vette has a 150 hp N2O system that is designed to only be operational at Wide Open Throttle (WTO) in addition it does not kick on until the engine is at 2800 rpms and kicks off at 6,000 rpm automatically! For $750.00 bucks you can have a Stock LT1 producing over 400 engine HP! If you install roller rockers you can rev to 6200 rpm's without valve float and pull another 10 to 15 hp on the top end. Check out the N2O organization on the web. You might change your mind.

Wookiebear

 

[Mad-Mic]

yes NOS is fun to use. i believe you can put a dry shot in to about 125 hp with out running any other fuel lines or extra fuel pumps.

with a good cam alone you could see upto 40+ hp but why would you not want to add the cam if you do the heads? cams only cost around 100 bucks or so true roller cams i think about 300 bucks then a set of true roller lifters and your done you got a true roller motor saving over 30 hp just from a true roller motor.

 

[wookiebear]

Southpaw AFR Heads

AFR (Airflow Research) Makes a cnc ported head for the LT 1 that is absoutely awesome 190 cc LT-1 Street Head. Go to http://www.airflowresearch.com and order their catalog. They make a LT-1 competetion package thats a little pricey $2,450 but it is a complete system that has been rated best overall by several magazines.

Good Luck

Wookiebear

 

[Mad-Mic]

AFR is a very good company heard many good things about them.....

 

[sothpaw]

LT4 hotcam &high rpm

Would I avoid the high rpm issues by going to a different cam or
just leaving the stock cam in there? It's not acceptable to me to blow the crank, etc because I put some performance parts in place.

What ever mods I do, I am hoping not to sacrifice much reliability or longevity, if any. I intend to keep the car a long time, but resale is also an issue as things not under one's control change sometimes.