L98 roller block-Flat tappit block
Thread Starter
Instructor
Joined: Sep 2009
Posts: 110
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From: seabrook tx
L98 roller block-Flat tappit block
Is the lifter bore the same on the L98 roller block as the L98 Flat tappit block?? My son had a machine shop build a roller motor,car got flooded out from ike.Engine has been sitting on the engine stand for 2 yrs. I want to put it in my 86,An use a flat tappit cam an lifters. Can this be done???
Racer
Joined: Jul 2010
Posts: 308
Likes: 2
From: Kansas City MO
My question - why go 'backwards' to a flat tappet cam? What's wrong with the cam that is in there? If the cam is "too wild" for your car then it's probably almost a wash or cheaper to put in a milder roller cam than to convert to flat tappet with all the associated hardware (cam, lifters, pushrods, matching valve springs, timing set). Good hyd. rollers can be had for under $250 new and if you find a zz4 take-out cam they can usually be had for $75-100.
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
The inside diameters of the lifter bores are the same but as to the height of the bores, themselves, I don't know. Perhaps someone who does can chime in of that.
It's important to know because of how the lifters would ride in the bores; oil passage alignment, pushrod length and maybe some other factors.
I recall reading in a CompCams article that going "back" (from roller to flat tappet) requires changing everything. The specifics weren't listed but I took it as Comp referring to cam, lifters, pushrods, timing chain set. Rockers should be re-usable though, but that's just a guess.
I agree with the previous poster; wondering about the wisdom of going back to a flat tappet. It always troubles me when someone wants to change something so dramatically; asking "How do I install a LS2 in my 85 Vette?" type of stuff. There are so mant details that have to be 'RIGHT'.
Jake
It's important to know because of how the lifters would ride in the bores; oil passage alignment, pushrod length and maybe some other factors.
I recall reading in a CompCams article that going "back" (from roller to flat tappet) requires changing everything. The specifics weren't listed but I took it as Comp referring to cam, lifters, pushrods, timing chain set. Rockers should be re-usable though, but that's just a guess.
I agree with the previous poster; wondering about the wisdom of going back to a flat tappet. It always troubles me when someone wants to change something so dramatically; asking "How do I install a LS2 in my 85 Vette?" type of stuff. There are so mant details that have to be 'RIGHT'.
Jake
Thread Starter
Instructor
Joined: Sep 2009
Posts: 110
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From: seabrook tx
This motor is just a short block,with no roller lifers an no cam.Its really a cost thing,I can buy a cam an lifters for the price roller lifters. Wont need to round up push rods eather.Have my heads done an i can have a rebuilt motor for 500 bucks.Complaments of my son.
Melting Slicks
Joined: Feb 2006
Posts: 2,753
Likes: 15
From: backwoods upstate ny
no 'i think maybe'
spring of '87, i put a flat tappet cam/lifters in an '87 vette, the owner insisted on a 'wild' cam and no aftermkt 'big' rollers were available yet...cam+lifters+pushrods+timing set wuz all, no issues while he had the car AFAIK.
