98 ls1 blocks
98 ls1 blocks what are the pros and cons of using a 98 block as opposed to a later model block like an 02?
i am asking because i have heard they do not oil as well as the later model blocks. any info would be greatly appreciated
i am asking because i have heard they do not oil as well as the later model blocks. any info would be greatly appreciated
If I remember correctly, older LS1 blocks had an oil crossover passage that wasn't as big as later blocks. In the back of the block you can look and see just two oil holes by the cam bore. Newer blocks had a passage that connected the two hole cut into the block and allowed for more oil the flow across.
As far as I know, thats the only major difference in the LS1 blocks. Compared to an LS6, they're supposed to be stronger because they don't have those windows below the bore for better bay-to-bay breathing.
As far as I know, thats the only major difference in the LS1 blocks. Compared to an LS6, they're supposed to be stronger because they don't have those windows below the bore for better bay-to-bay breathing.
So if you took the empty block to a machine shop to get cleaned & very slightly honed for some forged pistons basically the same saize as the stockers, could a machine shop enlarge the holes to allow more oil flow??
I dont see why you would have any problems running a 98 block...there had been plenty of them running in the 10's w/o a problem. So unless youre shooting for quadriple/high triple (750+)digit rwhp numbers, go with a 98 block. 
Trending Topics
Originally Posted by BrianC98Z28
570rwhp/540tq here on my stock 98 block. no problems. just changed the oil pump when i did the cam swap was all.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
Originally Posted by BIG_MIKE2005
So if you took the empty block to a machine shop to get cleaned & very slightly honed for some forged pistons basically the same saize as the stockers, could a machine shop enlarge the holes to allow more oil flow??
It's not the hole size, but the passage way that connects them; & yes, a machine shop could enlarge the rear passage way between the holes. If we're discussing assembled block differences, the 02/later model blocks have stronger rod bolts & I recall something different about the pistons, but, am not sure on the piston. Am thinking it had something to do w/a coating.
FormerVendor
Joined: Dec 2005
Posts: 250
Likes: 1
You can machine the oil crossover in the rear of the block to update to the newer design. I don't have a picture, but we have done it when re-sleeving the block. My biggest drawback to the pre-LS6 blocks is the un-equal length head bolts/studs vs. the equal length in later models for big power applications.
The weaker rod bolts in the 97 and 98 ls1 which is easily change if you need to reuse rods and only able to bore stock sleeves out .004 by gm specs also unequal length head bolts make them a little less desireable than other year models the oiling problem is easy to remedy like mentioned earlier . For a stock rebuild or mild set up I would still use it just change rod bolts or use aftermarket rods with a good set of pistons.
I CNC machine the early blocks for the oil crossover when installing MID sleeves. I machine the iron truck blocks too because they lack the crossover as well.
I have photos of before and after so you can see what is involved.
Steve
I have photos of before and after so you can see what is involved.
Steve
__________________
Steve Demirjian
Race Engine Development
Oceanside, Ca.
760-630-0450
web: www.raceenginedevelopment.com/
e-mail: race-engine-development@***.net
Steve Demirjian
Race Engine Development
Oceanside, Ca.
760-630-0450
web: www.raceenginedevelopment.com/
e-mail: race-engine-development@***.net
