85z51vette

Is it possible or has anyone tried to drill and tap the lifter valley in a non-roller block to use the "spider" and GM roller lifters? Anyone heard of/seen this done? Maybe even attaching the spider to the underside of the intake? Just a thought. What do you all think? :cheers:

edit: Let me clarify. A non-roller block has two "bosses" in the lifter valley. Would it be possible to drill/tap those and make two new holes in the spider to attach it??


[Modified by 85z51vette, 2:18 PM 2/19/2002]

85z51vette

TTT. :eek: :cool: :crazy:

moffitt

If the mounting boses are there it will work. But you have to tear down the engine for drilling and tapping (you don't want that drilling and tapping junk in your engine). I would go with an aftermarket hydraulic roller set up. It's cheaper! I have not looked at one lately, but I belive the lifter bosses are aslo machined some?

snaketr

Moffit was correct the lifter bosses are machined. I don't believe the bosses are there in an 85 block. They are in an early 86 but they had a different block because of the oil seal. It would be cheaper to use the crane rollers for a non-roller block. There is no machining required for these.

BBA

A few years back I opted for the retrofit speed pro hydraulic roller lifters ( and they worked to a surprisingly high RPM level as well ) instead of the adapting factory rollers/hold-downs. The top of the lifter bore has a flat machined surface on the new roller style block, that could not easily be machined into an older block.

The only draw back to the older style block with retrofit lifters is the bores are not perpendicular to the camshaft lobes. This forces the retrofit roller lifters roller to be thrusted to one side continously, which, in my case ended up wearing through the lifter body after about 4 years of use. This caused the roller wheel to break off and jam against the cam/lifter bore. ( lots of metal parts in the oil pan ). Basically, when I tore it down, the one lifter pair was shot, and all the rollers on all the other lifters had almost worn through their lifter bodies as well.

85z51vette

The 85 block has two bosses in the valley. Those are what I was referring to. I was wondering if it is possible to drill/tap those two, and make new holes in the spider to match up. My engine is already apart for a rebuild, so tear down is not a problem.

Gregory VanLare

I'm wondering what are the benefits of going with roller lifters and how major a project. I have an 85 with few mods, would this be worthwhile and a manageable winter project for a shade tree mechanic!

BBA

Using stock cams available, the roller will not give very much more than a slightly better power curve and a smoother idle.

BUT: roller lifter cams can give you WAAAYYYYY fatter power bands. How does an engine with 400 FT-LB's torque AT idle sound? Especially when it still pulls to 6500 RPM? Making over 400 HP at 5800 RPM?

That can not be done on a 350 CI motor UNLESS you have a roller cam ( a pretty aggressive one at that ). ( Well maybe you can do it with a supercharger, but a roller cam is much less expensive. )

lcvette

HELLO GUYS.. I just last night went down and put my 85 on a trailer and brought it home for some TLC.. the car has been sitting for about 3 years now and has a freshly built forged 355 TPI that is finished being put together minus the intake up. my question follows suit here with this topic, i have 2 full sets of gm roller lifters pushrods LT4 roller rockers etc.... i also have an lt1 and an lt4 cam with limited miles on them... my question would be that what machining exactly is needed on the L98 block, 85 specifically to be able to use them. i am familiar with the spider on the LT gen II's as i mainly work with these motors.. and was also wondering if a hydra rev kit would work in its stead... ALL YOU SPECIFIC INFORMATION ON THIS SUBJECT IS GREATLY APPRECIATED AS I AM READY TO TEAR INTO THE CAR ASAP!!


:smash: :smash: :smash: :smash: :D