lt1 block strength

[b-radlewis]

How strong is the lt1 block? What are some things to do to beef it up for a high horsepower forced induction build? My engine builder is trying to convince me to go with a dart sbc block but i want to keep the lt1? I know splayed 4 bolt billet mains but what else can be done to help make this block survive?

[INTrooper4255]

A lot of guys use block filler to I think "half fill" the block. I'm not real well versed in it, but a buddy of mine had a forced inducted LT1 355. When he bought it, it wasn't put together correctly and had too high of compression. It ate itself up on the track running an 11.20. The only parts left that were salvagable were the block, stock crank and stock ported heads. He took it to NuTek Motorsports and had another 355 built, same block, same stock crank with new internals and same heads. It put down 590 RWHP at Total Engine airflow after that with 10 pounds of non intercooled boost! He sold the car to a young girl who drove it as a daily driver and raced it for years. It's still out there driving, so the stock block and crank are stronger than what people think!

[CamaroZGuy]

there are many people on this board that are making 600-700hp on LT1 blocks. IIRC Fastbird just put down mid 700's at 18psi.

[AChotrod]

T-shep is like 845 rwhp. Theres been a few over 1000 but they are not on the board. The block is plenty strong for most builds.

[ZGOBYBY]

Yeah, I know the stock block is actually pretty strong. I am rebuilding my turboed LT1 this winter, and am using another LT1 block I have sitting around. I would not be concerned about the block's capabilities of holding up, I would worry about the other components first.

[QC97Z]

Stock block on my build, 4 bolt splayed mains. 648/585 on a conservative cam, 15psi front intercooled, no meth.

[RamAir95TA]

There are far weaker links in the LT1 design than the block. I would imagine a half-fill could take 1000+ plus handily.

[wicked96ss]

Stock block on my build, 4 bolt splayed mains. 648/585 on a conservative cam, 15psi front intercooled, no meth.


is that 648 rwhp?

[ItSSlowZ28]

yes, thats whats in his sig

[Paulster2]

T-shep is like 845 rwhp...
I'm pretty sure Tony is running his half-filled, but yah, stout.

[BLK95-Z]

A while back I asked Tony about this on facebook .

Tony -"I have never hurt an LT1 block in my 15 years of beating the hell out of them. I do however half fill them with block fill. 4 bolt main splay, and plug the deck."

[faust]

how does a half fill do on the street. is over heating an issue. just wanting to add to my knowledge base

[QC97Z]

My block is not filled at all. Running a half-fill or more can cause some heating issues, especially if you plug the deck.
Block filling is generally not advised for cars that see mostly street time. It's not bad for the strip, considering the car isn't running long enough to really get hot.

[QC97Z]

is that 648 rwhp?

:secret:

[kline454]

I run a half fill of hard block and splayed mains, Never had a problem, As far as street driving around town 30min trips havnt been a problem for me,But unless your making BIG h.p you dont need the hard block. i was running 660rwhp without any hard block, I did crack a cylinder but wasnt by fault of the block it was tuning problems...

[ZGOBYBY]

Interesting info here, and it makes me wonder if I need to get my block filled or not. Hmmmmm...

[Tony Shepherd]

Just FWIW, I ran a half filled block when my car was a daily driver running high 10's back in 1998. Contined to be my daily driver until around 2001-2002.

It is not a must do but I have had good luck doing block fill in every combo I have had.

[AChotrod]

Im doing a half fill in my 383. Ive never seen anyone complain about heating issues and why not its only a couple hundo and its great insurance youll have a super stout block. Now I just need to win the lotto for some killer heads.