I've heard 396 Lt1 engine blocks have to be clearanced to the point where the strength and structural integrity are compromised. Is this true? And if so, is there aftermarket engine block available that can bolt right in place of the factory LT1?

 

no aftermarket LT blocks.

I don't like grinding to do a 396.......it is so easy to hit water its not funny. I don't see any advantage of a 396 over a 383 anyway.......The 383 is even tight.

Doing them on a CNC I know people that have hit water...so I think most people do them by hand.....Mine I even milled the head bolt down slightly so I would not have to grind too much and I tried to get around .050 on each one

 

when i had the machine shop put my 396 short block together they were concerned the clearencing would hit a water jacket, and luckily they never ran into that problem. IMO if i had to do it all over again i would go with a 383, because of the clearencing issues,stress on the rings from large rod ratio,tehy make nearly idenical power numbers and the fact that when i go the short block back and turned it over to see the crankshaft counterweight BARLY miss the bottom of the piston. Just stick with a 383, if you really want more displacement its time for a LSx motor or a BBC.

 

Agree with what has already been posted. Even a 383 is stretching the limit of what the readily available heads and intake can support. It is even possible to hit water clearancing for a 383 - depends on the rods used and the casting - there is seemingly a lot of variability in the water jackets.

Rich

 

I figured as much. Thanks for the info!!

Jim

 

There is a guy, Pete K, on the Corvette Forum that uses block fill. He fills the bottom 1/2 to 1 inch of the block. Then he grinds away. He said he has ground into the block fill and never had any problems.

Nor any overheating...

 

The half fill works well. No problems here, and it does act to strengthen the cylinders and mains as well.

 

I was fortunate enough to have a shop who specializes in LSx/LTx strokers and was no problem for them to clearance my 396.

 

even a bit of core shift in the production can change things significantly from block to block though...

 

I was pretty careful when I did mine and after I went through on bore #5,
I got the partner saw out on boost and clearanced the rest in about 10 minutes. The block fill is definitely a viable option and nobody should be scared at all about using it. It does add stability to the block and is worth some hp. I have a 13 to 1 solid roller "street" motor that has had absolutely no heating problems whatsoever. Oil temps will be higher but an aftermarket splayed pan is all you need to help with that. Some people do get lucky though and clearance fine. My block though was not, and it wasn't because I wasn't being "careful," there was some definite shift or whatever going on.

 

that concrete will saturate overtime and eventually leak.....ask me how I know...


concrete is jive stuff man...nobody does that stuff anymore.....go o-ring the block when you fill it with some fifty cent concrete you pay $80 for

 

ARP makes a 1/2 head rod bolt so you dont have to take out NEAR as much material to let it swing.

My block is 1/2 grouted and yes the coolant will work its way under it after a while, pull the plug out where the knock sensor goes after a while and coolant will drip out.


David

 

Chad Golen is the "master" of building 396 LT strokers! I couldn't be happier with my Golen 396!

WD

 

A....how about 13ci. and more torque??
Interesting because I've just desided to go with the 396 over the 383 because I have been assured that the parts exist "today" that require very little clearencing. And do not require the small base circle cam.

 

Just thought I'd share my limited experience:

I had a very old, well qualified shop do all the machining for my 396.
-'94 block
-.030 over
-3.875in stroke
-Ended up using 6inch Eagle H-beam Rods (cleanancing done to rod bolts)
-LT4 Hotcam (not small base-circle)
-no block filler

They did all the clearancing by hand, and due to what else I was having done at the shop...didn't really charge me for it.

As far as "couldn't you have done a 383 instead"...yep, I guess I could have. But I chose a 396 and could not be happier with it. It's a lil' different, and in my case didn't cost me much more...and I sorta "fell into" the callies crank I'm using for next to nothing.

However, if you haven't purchased any parts, the added risks/complication of a 396 probably isn't worth it to many people.

Just my .02
-Andrew