LS1LT1 Forum banner

1 - 3 of 3 Posts

2 Posts
Discussion Starter #1 (Edited)
Hey guys, been away from the forum for a good while. I am back and building another LT-1 for my '94 Z28. I plan to use my old Powerdyne SC, and maybe add a FMIC. I have some questions for those who have already done this:
How much boost can I run on a 'near stock' lower end? (I know, it's all about the details, so...)

Here's my 'near stock' parts-list:
Sealed Power Speed Pro standard bore Hypereutectic (10.5 to 1) pistons w/ Hastings moly Rings
Comp Cam #07-500-8 (.258/.264 dur. .480/.488 lift, w/112* LSA)
Sealed Power Speed Pro stock style Roller-Lifters
Crane Push rods, with Crane Gold 1.6 Rockers
Melling stock style Timing Set
Federal Mogul Rod Bearings & Main Bearings
Durabond stock style Cam Bearings
Melling stock style Oil Pump
Melling Freeze Plugs
FellPro Gasket Set
ARP Crank and Rod fasteners
Gasket-matched, fresh grind and seals, Alum LT-1 heads,
K&N CAI, MSD 6AL, Edelbrock 'Shorty' headers and Borla exhaust

I realize I probably should run forged pistons, but bought this Master Kit years ago, so unless it's absolutely imperative to buy new pistons, I'll just have to live within its limits.
I need different springs to handle the .513(ish) lift with the 1.6 rockers, too. I plan to go with the single ovate Beehive springs. I was looking at Howard's springs (here- Howards Cams Performance Valve Spring and Retainer Kits 98113-K12) because they are about 1/2 the price of Comps and Howard's gets their springs from the same source as Erson and Manley, which should mean they are good, right?
Also, should I get different head gaskets- say Cometic or other aftermarket?

So, with the parts I currently have, what are your suggestions?
Would it be worth the time/money investment to add a Front Mount Intercooler?
I ran the stock engine on 4.5 lbs boost for 70K miles, before blowing a head gasket and overheating it. I'd like to get at least that much out of it this time around. Can I run a 6.5 lb pulley and expect longevity, with this setup? If not, what would I need to change?

FYI- The car has already got weld-in sub-frame connectors, Spohn Panhard, LCA Relocation brackets, Tubular LCAs w/spherical rod-ends, KYB 8-way adj rear shocks, etc. The trans is a fresh 4l60e w/ B&M Transpak and 2200 B&M stall. I'm sure I am forgetting a lot...

Thanks in advance for any input or suggestions!

Global Moderator
13,163 Posts
Supercharged car's that come from the factory usually have 8:5 to1 compression pistons or lower. I believe boost over 5 psi would blow your lt1, with it's stock 10:5 to 1 compression, sky high.

12 Posts
I am going to preface this by saying that I am NOT an expert in ANY application.

If it were my money, I would really consider some forged pistons and rods.My main worry is that Hyperutectic pistons are known for being a bit brittle. If your tune is not dead on, and detonation happens, they may not survive, and then you may also end up damaging other components. As much as I dislike spending extra cash, I have learned that doing things twice tends to be more than twice as expensive.

That being said, one other thing to look at is making sure that your fuel system is up to snuff. This would be a good opportunity to step up to make sure that you not only have enough fuel for what you want now, but what you will want later. I am familiar with boost, and I remember it being QUITE addicting, so having a bit of head room to go bigger is always a big plus in my views.

Outside of that, this sounds like a cool project. Would love to hear how you get this together! Keep us posted! (y)(y)(y)
1 - 3 of 3 Posts