Here's my specs.

98 Vette
Dart Pro1 205
LS2 (.051) gasket
Comp Cams High Energy OEM style lifters
Comp Cams 228/230 .571/.573 112

The majority of the individuals feel a lifter preload of .080" - .100" is a good fit for this combination. I'd like to order the pushrods soon so if anybody has any opinions on lifter preload please let me know. Does .100" seem excessive? Is .075-.080 on the low side? Anything I should be aware of?

 

Comp Cams recommends that lifter preload be set at .030" to .040". I'm curious as to why many recommend .100". It would seem that this would be near the end of the lifter's travel. Any comments?

 

Ok, I've been doing quite a bit of reading (this forum and corvetteforum) about recommended lifter preload and the only consistency is the inconsistency. Lifter preload recommendations are all over the board. For example some people running morel lifters are running .020" preload while others run .100"+ preload. Some people say that stock lifter preload is .20-.50" and other say it's .80-.100". Some people feel that the total plunger travel is as low as .040" while others believe that it is .100". How could we be looking at that much of a discrepency? Comp Cams recommends .030" - .040" for optimal performance while crane recommends .050"-.080". This seems to be one area full of black magic. Are hydraulic lifters that forgiving? I was thinking to average the advice I'd been getting and go with a .075" preload thinking that I might be on the low side. However, given my reading it looks like I way be way on the high end. I assume that there are differences among the lifter manufactures but can it be this disparate? There seems to be a lot of trial and error on this as well. Given the price of a decent set of pushrods it could easily take $400-$500 to get it right....yikes...no.....double yikes!

 

I know GM lifters say they should be from .080 to 100. I run the ls7 lifters so I tried to get as close to .080 as i could. I ran about .040 for a while and I had alot of sewing machine sound from not enough preload. I still would like to have a little more but if I go with the next size up pushrods I will be at .100 or a little more.

 

Morel preload is 0.030 - 0.050, but it is a different lifter design and shouldn't be considered as part of your decision.

I have measured several stock motors, they come out around 0.100". I wouldn't listen to Comp, their tech support line is useless. I have gotten answers that would have resulted in motor damage from them, I don't call them any more.

If you set them too shallow, they will be noisy and depending on preload any pump up could put you against the retainer clip and fail the lifter.

Whoever told you total travel is 0.040 has never disassembled a lifter and doesn't know what they are talking about.

Stay in the range of 0.080-0.100".

 

I agree, staying away from comp cams tech support would be a good idea. About how much travel does a oe style lifter have?

 

I remember reading 0.153".

 

Those arent the comp-R lifters, right? I was under the impression that the OEM replacement comp lifters were fine running stock preload, and it was only the Comp-R lifters that required adjustable rockers for .030-ish preload.

 

Nope, they are the OE style lifters. The Comp-R lifters looked a little too finiky for my taste

 

Like I indicated in another of your posts....

I am using LS7 lifters and have my preload at .100.

I have not had any issues and I do not have the "sewing machine" sound. I used the Comp PR length checker to get my initial PR length and then added .100 for the preload.

If you are using LS7 lifters, I would stick to Vettenuts suggestion and keep your preload in the .080 to .100 range.

Good luck on your build.

R/

Frat

 

I'm using Comp Cams OE style lifters