This 4.3 L 1991 Blazer has roller lifters. What is the lift? I bought a manual but its not in there[:@], even though it tells you to refer to the specs[:-]... The lift on this cam .251"-.259" on the intakes and .226"-.234" on the exhausts.... is there a tolerance? Journals are good.... does this cam need to be replaced?[&o]

 

whem it comes to adjusting your valaes and checking detailed specs you really need to know what youre doing it can get pretty complicated roller lifters are pretty much the standerd these days your book should refer to somthing called valve adustment and lash study the book carefully and understand it well caus eyou could open up a big can a worms if you make a mistake lift is the point of your valve opening and closeing wich requires precision mesurements i hope this helps good luck

 

The question that I am asking is: What is the factory lift of a stock 1991, 4.3L engine camshaft with roller lifters and a "Z" code..??? I do not have a factory service manual and the Haynes book that I bought refers to it but doesn't give the measurment. I just thought somebody out there would have a service manual.... Thanks

 

sorry, had to go to a picture to include more information.

 

Thanks... that's what I needed!! The reason that I needed the info is that if the lift is wiped off ofa lobe, say .015"-.020", then I ain't putting the cam back in.. The cam should be replaced... not so sure that .006" will make a difference.. the danger lies in the fact that if it is worn below the case hardening, it will wipe in a hurry... normally .015"-.020"

 

I am sure thatthe camshaftis a 1991..That .390" and .357" is probably the total lift..that would include the +1.5 rocker ratio..

 

Measure the base circle of the cam. It is possible someone put a different engine in at some point.

 

I just measured the base circle... It is a 1991 camshaft. The rocker ratio is x1.5 ..That equals .385 (.390) on the exhaust and .351 (.357)on the intake....

 

I wish I could follow this conversation..

one day...

 

The 1987-1991 4.3L S10/S15 VIN Z use p/n 10088148and p/n 14093686 camshaftswith 1.380" (I) base circles and 1.335" (E) base circles.The heads that usedthose camshave fully adjustable rocker arms and straight 3/8"-24 pressed-in rocker studs..

Here is where it gets confusing. Some of the1992-1993 4.3L S10/S15 VIN Z balance shaft engines use cams that havea 1.260" base circles on both cam lobesand have non-adjustable rocker arms with 3/8"-24 rocker studs that have a rocker nut jamming shoulder to set the lifter preload at 20 lb. torque butsomeof thoseengines had fully adjustable rocker arms depending at which plant the engine was assembled. All the 4.3L engines after 1993 had non-adjustable rocker arms and camshafts with1.260"base circles on all cam lobes.The 1992-1993 heads with screw in rocker studs have casting numbers626, 064,209 and 181. Those arethe last three digits of the full casting number. Those do not have the 7/16" lower threads that V8 Chevrolets use and the V8 studs wil lot fit. Stock 4.3L V6 screw-in rocker studshave 3/8"-24adjustment threads and M10-1.5 bottom threads.

It isa excellent idea toconvert from pressed-in rocker studs tofully adjustable rocker system at your first opportunityusing 350 Chevy V8 straight 3/8"-24 screw-in rocker studs and guide plates.