All else being equal, (cubic inches, compression, parts, head flow, intake, etc...).....how much power would an engine gain going to a solid roller over a hydraulic?

Street car ONLY, Roll racing ONLY, 50-180mph

If you want some specifics:

447ci resleeved LS7 block
Ported LS7 heads
11.5:1 compression
250 progressive DP shot
LS7 intake or a sheet metal


.

 

zero.


now, if you change the motor up for extreme RPM that the hyd lifters cant handle.. and/or started running such extreme lift that the hyd lifters cant handle the springs....

THEN you would gain by going to the soild..... only because you could then use what you have in the cam/heads...


until the hyd becomes a limiting factor, in reality, id say that the hyd gives MORE power for a street driven car.... why? because you wont have lash to move around on you.. because we all know damn well that someone isnt going to check their lash as often as they should on a regularly street driven car... that extra lash in there will end up costing more then the soild roller gives you..


and the more aggressive ramp advantage a solid roller gives is minimized on the LS1 due to its large base circles, and aggressive hyd lobes available.


really, for a street car, you gain nothing.

 

I'm running the revised LS7 GM performance hydraulic lifters in the 402 we're building. They're used to 8k RPM in the Cadillac racing engines.

 

FYI there are two lifters available
1)The lifter that was revised for use in the LS7 that was used in production
2)The GM performance lifter that never came in a production engine.

 

I'm running the performance lifter from the Cadillac racing engines.

 

I used to see 30+ rwhp gains going to solid roller. I would go Morel lifters and a 670 lift hyd cam. I have a 402 with this combo, just getting it broken in and then we'll get some numbers.

 

So, if I spin it to 8,000 rpm for the type of runs I want to do, will a solid roller be benificial HP-wise?


.

 

ttt...........any more opinions

Isn't a solid roller better for roll races?


.

 

While we're on the subject of hydraulic rollers, I have a question regarding solid roller lifters. When you're checking for pushrod length, etc. , your supposed to use a solid lifter even if you are using a hydraulic lifter in your actual application, so you get an old solid lifter to do your measurements. The problem is, there aren't a whole lot of them around for the LS family. Can SBC solid lifters be used? There must be a million of them in junkyards. Stupid question I know, but i don't know where else to ask it.

 

Quickin,

Sorry, I just realized I hijacked your post, but I was on the phone at the time and I'm not a very good multitasker, or maybe I'm too good. In any case, I apologize.

 

The type of lifters you have don't make a "crap" on a "roll" race.

 

Silicone boy: Any .842" dia SBC lifter can be used to measure. However, the simplest way is to convert an old hydralic lifter. Obviously, you can't just turn a hyd lifter into a solid and put it into a running engine, but you can use it to check valvetrain geometry. Google thhe topic. I bet you find some good info.

As far as a gain with a solid roller in the poster's app, I have zero experience in LSx solid rollers. However, the gains have become smaller and smaller in general. The LSx has awesome geometry in regards to valvetrain stability. That said, I don't think it would be worth it for a street racer ($-wise). I'd find bigger jets and smaller pulleys .

Whatever you do, find someone with experience in this arena and make sure they know what they are doing. A properly setup SR is going to cost some change, but an improperly setup SR will cost you an engine.

Ryan