tpi_roc

Ok I started by locating the hole, then predrilled it and increased bits untill I got to half inch, then I went with the 3/4" bit. Word of caution, learn from my mistake, do NOT use a hand drill.

my89gta

sorry

fun Pain

are the lt1 intake bolt pattern the same as the 87-95 sbc pattern or even an older pattern!!!

tpi_roc

www.lt1intake.com

Slow89Iroc-Z

U plan on mounting any accessories to the front of that motor??? I think you should have tapped them in the rear of the heads....

tpi_roc

No sir

tpi_roc

Distributor hole is drilled in the otherwise stock intake. I hope to have this engine in the car next weekend.

Igor

... this is a WICKED post. Specially for a guy like me that has a complete LT1 topend for parts!!!

Keep us posted, great work man!!!

SOLOMOTORSPORTS

What kind of headers do you run 3rdgen or 4thgen?

bowtienick

iTrader: (1)

im new to these forums. but here goes . i thought of this same idea when i saw how cheesey the tapping into the manifold looked. i used a set of zz4 heads, and mapped it out where i could go through the stock acc bracket and the head. if i can figure out how to post pics i will.

tpi_roc

you want thirdgen headers

Its getting installed tomorrow, so here's the last pic before it goes in.

DuronClocker

iTrader: (1)

Looks nice, I want to hear how it turns out. Where did you get to weld up the heads? Like what kind of shop? All the welding places around here tell me they don't want to deal with it for liability even though I say I understand the risks.

Those look like SLP 1 3/4" as well, right?

Where did you get those 90* bends from? Those are nice looking.

tpi_roc

Yes they're SLPs, earls russel and nonammers all make 90° AN fittings. Try summit/jegs/whoever. Also another source for cheaper brass fittings is hydraulic supply shops and hose builders.

Street Lethal

iTrader: (16)

TPI-ROC, you've got suuuuum patience. It came out awesome, and I can't wait til you dyno that thing. Excellent!

tpi_roc

The engine is in but hasn't ran yet. Doing finishing touches this week.

tpi_roc

The engine ran today for the first time. They deffinatly work and boy does it sound good. I still have to tie up some loose ends and road test it but things are looking good.

CC89Formula

Are the valve covers the same for an LT1 as an L98? someone said they may be different so it got me thinking.

tpi_roc

Yes they're the same

85 roc it

Do you have any pics of your accessory set up. I'm doing the same thing, but the shop drilled the whole it the front of both insted of the front of the pass and back of the driver.

tpi_roc

Yea I'll take some of the pulleys and with it installed in a few days. I'm only running water/alt/PS though.

85 roc it

Same here, I did find a midmount alternator bracket, probably going to run it, It was the only one that didn't mount infront of the head.

tpi_roc

my stock 85 alt bracket worked just fine.

85 roc it

Good, same thing that I have, so sounds good

DuronClocker

iTrader: (1)

Finally getting mine done. Found a place around here that will weld, mill, and drill/tap the coolant holes where yours are for a good price. Sending off my intake to Millican tomorrow for the distributor mods.

tpi_roc

I dont see how this is relevant?

nwcc

tpi_roc... I wanted to thank you for leading the way on this conversion. I'm sure that I am not the only person thats been motivated to take on this project after reading this tread. Again, I just wanted to thank the people who run and support this great site and I wanted to thank tpi_roc for his documentation of this conversion.

tpi_roc

I appreciate that. I also echo the comment about the greater people of thirdgen.org.

bowtienick

iTrader: (1)

i have a 91 with serpentine set up. i bored through the acc bracket on the driver side. on pass side i notched it and went behind (not running a/c).

ajclark7

I see you got your engine in and running. How is the engine cooling? I have mine ready to install, I'm just waiting on my tranny to arrive. Good luck, your engine looks great.

tpi_roc

Thanks for the compliments, I haven't been able to really test the coolant system yet but I should be by the weekend. I managed to blow the nose cone off my starter somehow so that slowed me down a little.

85 roc it

Did you have trouble tapping the heads, my treads didn't turn out that well, the guys at Napa said that the Aluminum used was cheap

tpi_roc

It tapped very well, however like I mentioned before, drill with a press, not a hand drill.

ajclark7

what type of rocker arms did you use? I was going to order some comp pro magnum 7/16 rockers for mine, I'm not sure if they will work.

85 roc it

I would use 3/8, the 7/16 may be to big for the bolts that hold down the valve cover, at least that was what I was told

tpi_roc

Coolant is 100% completely done, holds water, purges air, and looks nice! I'm going to clean up the engine bay and take some pictures, and road test this weekend.

DuronClocker

iTrader: (1)

Great to hear its working so far. I have my heads assembled and I have the brass fittings for the coolant lines as well. Where are you locating the remote t-stat housing? I'm trying to decide where to put that. I'm waiting to hear word back from Millican about my intake and fuel lines and then I'll be getting my stuff installed as well.

Just out of curiosity, what were your chambers CC'd at, and what pistons are you running?

tpi_roc

You have a PM




The pics will illustrate everything. If anybody has a question from there feel free to ask. I'll get some up tonight or tomorrow.

tpi_roc

nwcc

Looks awesome.

I bet it runs even better than it looks.

tpi_roc

Click for more pics

jconrad

Wow. That looks sweat!
It looks like alot more work than what most people were anticipating I bet.
What are you going to do about the radiator overflow tank? Just use a small one that goes up against the radiator?
So how does it work for cooling, compared to it as previously being a reverse flow cooling system? Do you expect any detonation problems, or is there someway to make this setup a true reverse flow?

tpi_roc

Making it a true reverse flow system is a little more tricky but people have been doing it to first generation smallblocks for a long time now. As far as the overflow bottle mine was just ugly as sin and I'm ordering a new old stock bottle to replace it.

So far at part throttle break in I dont see any detonation problems. I'm also at 11:1 compression so if it works with that, it'll happily work on an L98.

tpi_roc

I have been driving it daily without any issues. I mounted the power steering pump last night and will finish it tonight and finally be able to turn. Break in is a quarter way done on the clutch, soon after I can start tuning higher RPMs and get a feel for whether or not this was worth it. I'll report on performance when I've got an idea.

bowtienick

iTrader: (1)

looking at your throttle bracket, it looks like you modified the stock one to fit the lt1 intake. is that what you did? if so, how?

tpi_roc

The throttle bracket is an lt1 bracket, 93 If I remember correctly.

tpi_roc

Final Thoughts

Everything is broken in now. I can only pull to about 4700 RPMs because I've run out of injector to fuel it. I used to pull to 6500 with my other LT1 intake on 200cc sportsman heads. After a bunch of tuning all signs point to quite a bit of power and I cant wait to quantify just how much. Its tough to keep the tires stuck to the road but when they do it pulls like a mother @#@#er. I'm very happy with the outcome, for a while there I was worried the whole project was crazy. I also get a lot of compliments on how it looks which I wasn't expecting but is a nice surprise. All in all if you have the time and resources, and you want a pretty damn custom build, (that seems to produce) I say go for it.

85 roc it

what type of pulleys did you use, mine is almost done, engine is complete but had to get longer push rods. Plan on installing all in a couple of weeks, just need to do the intake. Plus I changing the whole car to a 90 mapo setup with a 4th gen TA dash and interior, thats going to be the fun part, I'll let you know how it all comes out.

tpi_roc

Stock pulleys

nwcc

Yesterday was judgement day for my LT1 head conversion..... I finally found the time to throw it on an engine dyno.

After a few shake down runs to get the timing and fuel curves under control. With the fuel ratio's rich and 38' total timing, It layed down 392 hp at 5500 and 446 ftlbs at 4000. Lets fast forward through several runs of tuning the timing,fuel curves, cam timing, and fuel preasure. the best run was 482 hp at 6000 and 481 ftlbs at 4300. I didn't have enough time to make a pull with nitrous. I can only guess that if I ran the 175 shot of nitrous that I should net somewhere between 625 to 650 hp

My engine combo is as follows

350 4 bolt block bored .030" over
Moroso windage tray
Crank scraper
3.48" scat forged crank (knife edged)
Eagle 5.7 con rods
Flat top JE pistons with a compression ratio alittle under 11.5 to 1
Ported LT1 heads
Ported and port matched GM LT1 intake
58mm throttle body

Custom ground solid cam:
238 int 248 exh duration at .050" .509 int .529 exh lift
272 int 282 exh adv duration 110 lobe sep.

Crane 1.6 roller rockers
Headers with 1 3/4" primaries.
Electric waterpump.
175 shot of nitrous thats progressively controlled
Last but not least, the engine is managed by Accel DFI (thats the whole reason why its heading for the dyno.


Overall I am very happy with this conversion. After my wife gets home from her photoshoot with our other laptop I should be able to scan and post the dyno printouts.

DuronClocker

iTrader: (1)

That's simply amazing. I got my car running two days ago with the LT1 heads and intake. Today I'm going to fix a few coolant lines and drive it. I was making my own setup for the rear coolant lines (just the small vapor lines) but I've realized that is completely unnecessary on these engines as I got no air bubbles out of those lines, and it was just a smooth stream of water. I'll be buying pipe plugs today to plug those holes up.