Keith Craft 482 8 Stack EFI Engine Build

[undy]

Originally Posted by FUNFER2

They hydro's can not take 6,000 (+) rpm's. They will break apart and cause major damage, of course. If you consistently run high RPM's, that's where a solid roller is made for. Keep a hydro under 6,000 and they are fine.

Don't know where you come up with this stuff sometimes Kevin... I know quite a few hydraulic rollers that consistently run 7000 to 7500 RPM and last way past 100K miles. Don't make assumptions based on antiquated SBC experiences.

[FUNFER2]

Just because they & you suck buddy !

I've always been a solid guy and have never had issues on the track or street, if you don't mind lashing valves a few times per season on the street, racing every time.
You can't tell me that hydro's are just as good at constant 6,000 + RPM's VS solids.

Since you're a hydro only guy, that's fine as well, so what ever turns your crank, ....you cranky old man and go back to bed.

Hydro's have come a long way, and like Martha Stewart says, "and that's a good thing".

[undy]

Originally Posted by FUNFER2

Just because they & you suck buddy !

I've always been a solid guy and have never had issues on the track or street, if you don't mind lashing valves a few times per season on the street, racing every time.
You can't tell me that hydro's are just as good at constant 6,000 + RPM's VS solids.

Since you're a hydro only guy, that's fine as well, so what ever turns your crank, ....you cranky old man and go back to bed.

Hydro's have come a long way, and like Martha Stewart says, "and that's a good thing".

Sticks and stones...

Valvetrain noises and having to adjust valve lash is not the problem. It's the solid roller lifters spitting tiny needle bearings throughout my once healthy engine. Numerous and extended idling times coupled with inadequate lifter bearing lubrication at idle is what usually takes the lifters out on a street car. Those little needle bearings always seem to find a place to come to rest where they shouldn't be, bringing about an engine teardown. Some will argue that a couple manufacturers have developed a new style solid roller bearing that will survive street bumper to bumper cruises. I'm just not buying into it yet...

As Brent sort of said, If you lighten up the valvetrain (valves, rockers, springs, retainers, locks etc, etc.. ) you can extend your max RPM significantly. Add a light weight crank, titanium rods, ultra light pistons then you have a 7500 rpm barnstormer that go for over 100K miles without cracking a valve cover. At least that's my story.

[blykins]

You have to weigh the pros and cons of each one.

A solid roller will allow for a more aggressive lobe profiles and higher spring pressures. Makes it a little easier to hit the higher rpms without much thought involved. Almost anyone can slap in a solid roller cam, lifters, set the springs up, and turn big rpms.

A hydraulic roller will be less tolerant of higher spring pressures just because the spring pressure will start compressing the lifter plunger. There are ways around that and you have to remember that the spring pressure needed will be dependent on the weight of the valvetrain. You can make a hydraulic roller turn 8000 rpm if that's what you want to do. NHRA stock and super stock 5.0 Mustangs do just that, and they do it reliably. An FE will require a little more brain power as the valves are usually longer and heavier, valvetrain is heavier, etc., but it can be done.

With all that being said, you're TONS more likely to lunch a solid roller than you are a hydraulic roller. Since there is lash involved in a solid roller, you have constant pounding of the bearings in the lifter. There are $$$ lifters out there with bushings instead of needle bearings, and are offered to last 25-30k miles. I've got quite a few sets out there in engines, but with the time it takes a Cobra owner to put 30000 miles on an engine, I may not ever find out if they will last or not...

[FUNFER2]

A hydraulic roller will be less tolerant of higher spring pressures, but guys seem to want high pressure with both double springs. Either way, what are the things you can to them and not to bend, snap and even float the valve at high RPM's ?
What are the safe guards for the FE, including not floating valves ?

Should just put a Chevy in, a lot cheaper & easier.

[scottj]

Originally Posted by FUNFER2

A hydraulic roller will be less tolerant of higher spring pressures, but guys seem to want high pressure with both double springs. Either way, what are the things you can to them and not to bend, snap and even float the valve at high RPM's ?
What are the safe guards for the FE, including not floating valves ?

Should just put a Chevy in, a lot cheaper & easier.

Everything as light as possible. With a 2.20" titanium intake valve, titanium retainers, light weight lifters, and the right lobe I turn 7500 rpm with 155/410 springs. That's not to say an FE will turn that with the same parts, as Brent said, the FE stuff will be heavier.

Edit: The LS7 also has light weight and strong rocker arms which helps too.

[FUNFER2]

Can you say,..$$$$$$