Greg88

Hey guys, there is a semi local guy to me that is selling his LT1 longblock and I want some suggestions whether I should go for it or run away?
here are the specs that i know of

its a LT1 block
bored .030 to 355
Mahle Powerpack 5cc Forged Pistons (Setup for 150 Shot... Never Run)
Eagle Forged 6” H-Beam Rods w/ ARP Rod Bolts
Polished and Balanced Stock Crankshaft
ARP Studded Mains
Clevite Race Bearings
Melling HV Oil Pump
Cloyes Single Roller Timing Set
95' Timing Cover
Stock Oil Pan

Heads are AFR 190cc
started out as 64cc milled out to 60cc
.030mls gasket
dual springs
they flow 294 cfm at .600"

cam is a custom grind LE cam
223/230 112lsa

motor is set up for emissions and still passes.

also has the 24x efi igition system on it, aswell as the front accessories, and electric water pump. He says its 11:1 compression. This is all I really know.

He is asking 5000$ canadian for this, has about 10-12k km on the motor. what is your opinion?

RamAir95TA

Sounds like a decent deal but the mileage is a bit worrysome. It might sound low but that's a good amount of mileage (IMO) for a performance build.

You always have to be prepared for the worst when buying used performance engines.

Injuneer

The only red flag I see there is the HV oil pump with a stock pan. Some people using that combo have experienced low oil flow due to the pan running dry.

Hard to see how it would see a 11:1 CR, with a 60cc chamber, if the 5cc means a 5cc valve relief. Would take a 0 deck height.

Greg88

he did tell me it was a zero deck height. So does that mean it could be 11:1?Also when he says the heads have been milled from 64cc to 60cc does that mean its smaller? So in that case a sleeve would have to be put into that?

I get to hear the motor run still. Anything I should try and look at directly? besides the basics of listening for rattles and such?

Injuneer

The AFR LT1 heads were derived from their Gen 1 smalll block Chevy heads. Those heads typically have a 64cc combustion chamber. The LT1 stock heads have a 54cc chamber. The bigger the chamber, the lower the compression ratio. The use of the term "milled out" in the initial post above is misleading.

The practical way to reduce the combustion chamber size is to mill the surface of the head that bolts to the block. No sleeve involved. As you take material off the head surface, you reduce the thickness of the head at the water jacket. You also increase the horizontal space between the angled mounting surfaces for the intake manifold, so now the manifold need machining.

Run your info through a compression ratio calculator and see what you get.

Injuneer

I ran it through a calculator. With the 0 deck height you would be at 11.2:1. With the piston 0.020" in the hole, it would only be 10.6:1

Greg88

ok so if it was as the guy selling it to me said, zero deck height, it should be 11.2:1. is that easily ran on 91 pump gas? All the engine builders in my local area that i have spoke to said, thats way to high for a street car. but what i read on here, its not that bad? now what is it?

Greg88

also, what is a good oil pan I can run, on my car to prevent that oil pump going dry? My car is lowered so i dont want anything to large.

RamAir95TA

While the compression is still an important factor on determining which octane fuel you can run what is FAR more important is the TUNE and the efficiency of the cooling system. The cooler the engine runs and the better the tune you can run lower octane fuel. My 383 is above 12.5:1 in compression and runs knock-free on 93.

The problem with everyone who cries about the higher compression is that they all have SBC-syndrome. LT1s are a different animal. Because the reverse-flow cooling cools the heads first we can run MUCH more compression than the typical SBC. Heck LT1s came from the factory with 10.6:1 compression - tell them that and see what they think then.

An easier solution to the oil pan situation is to put in a Melling 10554 pump. The HV pumps usually complicate things far more than the little to no value they add.

Greg88

ok great thanks!

parkers Z28

Watch out for the electric water pump !! one more thing to think about is how many of those miles are down the drag strip???

Greg88

he said he never had it down the drag strip. He also said it made about 376rwhp/377rwtq full emissions. He also said thats up to 6,000rpm, where he was using single springs, and he had valve float. he has since put in the dual springs, where he now runs up to 6,500 rpm. He thinks and so does the tuner that its over 400rwhp? do you think its capable of running around 400 with that set up?

KW Baraka

This engine --->> https://www.camaroz28.com/forums/par...-block-870670/

Plus a set of LE2 heads.....FTW.

You get a fresh (zero miles) engine/heads for roughly the same price......with no mystery whether the engine is built right.....or with the specs.

And you'll probably pull around 400 HP/TQ at the wheels, too.

Jus' sayin' ......

KW

skipjobe

I have gone pretty extreme on my LT1 we are approaching 750 RWHP but if I had it to do over I would start with a LS motor, 12 degree heads are far superior to a 23 degree headed motor. You can take the LT1 along way but it costs more to achieve the same power levels. My signature is out dated.

Greg88

I was thinking about doing the swap, but i think it would nickle and dime me to death. Relastically it would probably be cheaper for me to just buy a LS1 car (98+), and start from there. I have owned this car (lt1) since i was 18, and i dont want to sell it now. I dont want to end up with 5k into swapping this out, and then im still stuck with a stock motor. I dont plan on running anymore then 500hp at the most. Kind of looking for a nice street/strip motor and reliable. I dont know!! decisions suck i guess