93turbo5oh

Ti valves help with that. one of the biggest things i like about running a SR is that you can limit oil flow to the top of the motor which helps make hp by having less fall back into the pan past the cam and rotating assembly. it takes a damn oil refinery to keep 16 stock HR lifters fed at 7K. not to mention the extra weight. even class racers who have to run HR lifters reduce the plunger travel from .200" to .010".

Fastbird93

The cam profile would play heavily into this though I presume. But with a more agressive profile, how bad are we talking here?? Are we talking about annual rebuilds on the heads or what??

FYI, the car will probably see no more than about 5K miles a year once driveable. It's only seen about 800 in the past two years. TOPS. But there's reasons for that.

MachinistOne

Like was said above it depends on the lobe profile (how gently it sets the valve down) and milage/abuse over a certain time period.

Our GTA cars get a season on the motor and then the seats show about a .010" recession of the lap line, which requires a valve job, and if you are going to shoot the seats you should replace the guides if they show any wear because the seat cutters center off the guide. Now these motors live above 5000 rpm their whole life so the wear is accelerated...but still thats not much time considering so few races over a year.

I rarely put a solid roller in a "daily driver" it's always in weekend cruisers, race cars, or other toys that get them, and those don't get much time on the motor per year. But when they come apart for a re-fresh, the seats are hammered.

Just because the parts show a lot of wear does not mean that the motor starts loosing power, the seats still seal perfectly, it's just that re-build time comes quicker and is potentially more expensive.

rskrause

A point I tried to make before was that a "mild" SR profile, which avoids many of the problems attributed (correctly) to SR cams is really not going to perform much differently than an "aggressive" HR, which will be cheaper and more convenient to run.

Rich

Mindgame

6500+ RPM, go solid.... up to 6500, stay with the HR.

You can turn revs with a hydraulic, you just need the right part$ and the know how to do it. I built a 355 last year for a friend that spins to 7100rpm without fail. Granted, it has expensive hollow stem Ferrera valves and other parts in it but I don't doubt they helped us out a bit.

I'm one of the few who prefers a mechanical over a hydraulic... then again, I like to go alot faster than the compos mentis.

Besides that, the heads I like to use don't play well with hydraulics.

-Mindgame