95 lt1 block?

Kdw1403 · 10-09-2019, 11:18 PM

Is it legal to run a regular old style Chevy block rather than a LT1 block in a 98 Camaro in stock eliminator ?

Greenlight · 10-10-2019, 02:58 AM

Yes, as long as the main bearing size is the same. In other words, you can't run the small main journal Chevy pre-1968 block.

The blocks are NOT a direct replacement. The LT block has a completely different cooling routing system, unique front drive distributor, different timing cover, etc.

Others have converted an LT engine to a earlier generation block, but it's not that easy.

Dyno · 10-10-2019, 09:39 AM

Maybe in Superstock, but in stock you must use the Opti-spark, which requires the LT1 block.

Whalen3186 · 10-10-2019, 10:05 AM

MSD and stock GM Opti-spark's will work the traditional style sbc blocks.

ss3011 · 10-10-2019, 11:09 AM

Quote:

Originally Posted by Whalen3186

MSD and stock GM Opti-spark's will work the traditional style sbc blocks.

Inquiring minds want to know how to do this ? What would you use as a waterpump ?

Whalen3186 · 10-10-2019, 11:41 AM

Quote:

Originally Posted by ss3011

Inquiring minds want to know how to do this ? What would you use as a waterpump ?

Standard sbc water pump with spacers to clear distributor. Water flow can be either direction, these motors don't see enough temperature to need the reverse cooling.

ss3011 · 10-10-2019, 11:49 AM

Quote:

Originally Posted by Whalen3186

Standard sbc water pump with spacers to clear distributor. Water flow can be either direction, these motors don't see enough temperature to need the reverse cooling.

Seems to me the issue is how to adapt the front cover to the old style block . Isn't the shape and bolt pattern very different . Also wouldn't the water in the heads be deadheaded .

Rich Biebel · 10-10-2019, 12:40 PM

Rare they are but they did make Bowtie LT-1 blocks....

They were made in a std 4" bore size and a larger bore....4.125"

I took delivery of 1 for someone who found 2 or 3 available somewhere.

I was aware that Bowtie blocks could be adapted for use in SS with a belt drive distributer but never knew of or saw one in Stock adapted somehow to drive an Optispark distributer with the LT-1 timing cover....on a std type block....

An Interesting topic....

KRatcliff · 10-10-2019, 12:57 PM

Quote:

Originally Posted by ss3011

Seems to me the issue is how to adapt the front cover to the old style block . Isn't the shape and bolt pattern very different . Also wouldn't the water in the heads be deadheaded .

Drew is right and it isn't all that complicated. You do have to weld up the water passages on the LT1 heads (legal by tech) and fill in the top of the timing chain cover with epoxy for the LT1 to adapt to a SBC block. The LT1 timing cover has somewhat of an overbite is the best I can describe it when placed on a SBC block.

There are two water passage plugs on the heads that you remove with an adapter that bolts on to adapt to an -AN fitting. A standard SBC water pump with enough spacers to make a good border wall will be necessary to clear the Optispark or MSD. I suggest that you use the largest water return lines and -AN Y fitting coming from the heads that will fit.

Hope this helps.

KRatcliff · 10-10-2019, 01:02 PM

I forgot to mention that the reverse cooling for these engines was a way to somewhat battle detonation on pump gas and utilizing higher compression for a street car. We can and do run much higher octane with our racing fuel so it is a moot point on how it cools from the top down or bottom up.

Just make sure it cools.

10-09-2019, 11:18 PM	#1
Kdw1403 Member Join Date: Nov 2016 Posts: 202 Likes: 47 Liked 68 Times in 22 Posts	95 lt1 block? Is it legal to run a regular old style Chevy block rather than a LT1 block in a 98 Camaro in stock eliminator ?

10-10-2019, 02:58 AM	#2
Greenlight Member Join Date: Dec 2004 Posts: 214 Likes: 15 Liked 79 Times in 22 Posts	Re: 95 lt1 block? Yes, as long as the main bearing size is the same. In other words, you can't run the small main journal Chevy pre-1968 block. The blocks are NOT a direct replacement. The LT block has a completely different cooling routing system, unique front drive distributor, different timing cover, etc. Others have converted an LT engine to a earlier generation block, but it's not that easy.

10-10-2019, 09:39 AM	#3
Dyno Senior Member Join Date: Dec 2002 Posts: 905 Likes: 1,097 Liked 659 Times in 196 Posts	Re: 95 lt1 block? Maybe in Superstock, but in stock you must use the Opti-spark, which requires the LT1 block.

10-10-2019, 10:05 AM	#4
Whalen3186 Member Join Date: May 2008 Location: Illinois Posts: 240 Likes: 20 Liked 107 Times in 30 Posts	Re: 95 lt1 block? MSD and stock GM Opti-spark's will work the traditional style sbc blocks. __________________ Drew Whalen Stk 3186

10-10-2019, 12:40 PM	#8
Rich Biebel VIP Member Join Date: Jun 2007 Location: Northern New Jersey suburbs Posts: 2,312 Likes: 25 Liked 543 Times in 212 Posts	Re: 95 lt1 block? Rare they are but they did make Bowtie LT-1 blocks.... They were made in a std 4" bore size and a larger bore....4.125" I took delivery of 1 for someone who found 2 or 3 available somewhere. I was aware that Bowtie blocks could be adapted for use in SS with a belt drive distributer but never knew of or saw one in Stock adapted somehow to drive an Optispark distributer with the LT-1 timing cover....on a std type block.... An Interesting topic.... __________________ Rich Biebel S/C 1479 Stock 147R

10-10-2019, 01:02 PM	#10
KRatcliff Senior Member Join Date: Sep 2011 Posts: 762 Likes: 75 Liked 522 Times in 140 Posts	Re: 95 lt1 block? I forgot to mention that the reverse cooling for these engines was a way to somewhat battle detonation on pump gas and utilizing higher compression for a street car. We can and do run much higher octane with our racing fuel so it is a moot point on how it cools from the top down or bottom up. Just make sure it cools.