Hello everyone. I'm in the middle of assembling my shortblock and I have two questions

1) My L98 roller block had a cam retainer plate bolted to the block to hold the cam in. The non-roller block that I got from a 91 block (which I'm building right now) doesn't have provisions to bolt the cam plate on. I heard from friends that it would be okay if I left the plate out all toghether! Should I install a "cam button" ? Drill the block for the correct holes ? Or just leave in there like it is.... ?

2) Question about rings. My rebuild book says it's very important to correctly install the TOP and BOTTOM compression rings in their respective places. Only problem is... my rings arent marked and they all look the same. How would I know which ones go in the top groove and which ones go in the middle groove ?


Thanx

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92 Z28 L98 350
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Ported and polished heads, ported stock TPI base, ported plenum, Comp Cams XR270HR-10 cam (lift .495/.502 duration 218/224 lobe separation 110), Edelbrock TES headers, LT4 valve springs, Crane AFPR, Flowmaster catback with LT1 style tips, MSD coil & wires...

"Take that auto, drop it in first, hold the brakes, stomp the gas and grin from ear to ear! :-)

 

A '91 block without roller cam provisions???
Not sure that existed but WTF.. maybe. Is it a one-piece rear seal and does it have the 3 towers in the lifter valley pre-drilled for the lifter retention hardware... if neither of those 2 are true then it's not a '91 block to the best of my knowledge. Or is it that the 2 holes for the cam plate aren't drilled out??? 87-96 take 1 size cam plate, 97 and newer take another size. The holes were relocated inward for '97 by about 1/8" or so.
Anyway, a cam button is needed for a roller type cam in a non-roller block... I guess it wouldn't hurt a non-roller cam either. Are you using a flat tappet hydraulic cam in this motor? Or are you paying the price ($$$.$$) for retro-fit hydraulic rollers?
Rings: Every set I've ever gotten has come in a divided box with packages marked top, second, oil, blah blah. It all depends on the mfg'er. Use the instructions that came with the rings as to identifying them if necessary. Sometimes there are no differences. I put total-seal gapless into the chicken motor... no way to be confused about them.

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'89 Formula - Thunderchicken - 355 Vette L98/T-5/3.45 9-bolt/black/t-tops - the fun car!
'90 GTA - The GTA - 5.0 LB9/TH700/3.27 9-bolt/black/t-tops/tan leather - the cruiser.

 

Yeah unfortunately it doesnt have the spider bosses OR the cam plate holes or even bosses for it. It is a one piece rear seal though. Strange eh ? It came out of a TBI truck. I'm putting a roller cam in it and I was told my original roller lifters should work fine as the block should already be machined to accept these. I had the machine shop drill some holes for the spider and installed 3 studs to hold the spyder.

 

Sounds like a funky '86 block to me. Helped a buddy rebuild an '87 TBI truck in the spring and his was drilled and had the bosses for the cam plate but that was running a flat tappet cam anyhow.
I took the '86 block I got and gave it to a buddy to use for a boat moor in Lake Sacandaga and got a couple newer blocks at a swap meet (2 fer $150). The '86 didn't have the bosses for the cam plate either but it had the towers for the spiders but not drilled out. One piece rear.


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'89 Formula - Thunderchicken - 355 Vette L98/T-5/3.45 9-bolt/black/t-tops - the fun car!
'90 GTA - The GTA - 5.0 LB9/TH700/3.27 9-bolt/black/t-tops/tan leather - the cruiser.

 

you need a way to keep the cam from walking out of the block, either retainer plate or cam button. you need a way to keep roller lifters from turning in their bores. hardly ever see rings not marked top. look very carefully. should be a sheet with your rings that tell how they mark them. all rings come packaged either top, or 2nd. not interchangeable.

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ICON MOTORSPORTS

 

Blade: Relative to your ring questions....
The rings not only have to be in the correct groove (Top or intermediate) but they have to be correct side up. Why are they intermixed? I hope your not going to say the rings are used. If so, replace the rings with new & hone or deglaze the block bores.
Assuming the rings are new.....
The correct side up is the side that has an identifier impression mark on the side of the ring. That would indicate the top side of the ring & would go toward the top of the piston.
Now for the hard part, to answer your question which are top rings & which are intermediate rings. To do this you have to examine the face of the rings, this being the surface that rides against the cylinder bore. The top ring should have either moly or chrome on its face. The intermediate rings are plain iron without a coating on its face. Maybe view the ring by looking at a 3/4 view of the ring gap edge & the ring face. Start by comparing 1 ring against all others until you can at least identify a different looking ring. Then you will have at least the 2 different looking rings. Then sort them into the 2 groups, 8 & 8. Finally, decide which group has a coating on its face & which are plain faced.
Regards, FJK

 

Just to clear something up... There should be flat machined areas on top of the lifter holes for a factory roller cam setup. This is where the retainers (under the spider) rest. If these aren't there then that is indeed an '86 block and you'll have to go to aftermarket retro-fit roller lifters.

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'89 Formula - Thunderchicken - 355 Vette L98/T-5/3.45 9-bolt/black/t-tops - the fun car!
'90 GTA - The GTA - 5.0 LB9/TH700/3.27 9-bolt/black/t-tops/tan leather - the cruiser.

 

Thanx for the clear up. My block doesn't seem to have those areas machined like you described. I couldnt take a look at the old block since I got it sitting upside down on my garage floor. Looks like I will have to go get a good old flat tappet cam for this block

 

You'll need a thrust washer and a thrust button. The washer goes between the cam gear and the block while the button goes between the cam and the timing cover. I would recommend a billit cover to prevent flex. The Cloyes cover has an adjustable button built into it. Nice unit.

I'm trying to find the true story on the GM truck blocks and when they went roller. I'm hearing different dates and experiencing differences myself. I rebuilt a factory '91 with a roller cam and I just saw a '93 with the bosses but a flat cam. Don't know what's going on there.

The rings should definately have a mark on them to indicate which side is up. Look for a small dot near the ends. The second ring will typically have a slight taper to it if you look at the end of the ring. It will also have a champher on the top inside corner (if you look at it from the end). The champher lets the ring rock slighty and scrape oil as the piston goes down.