[Formulajones]

Originally Posted by ponjohn

Pontiac dude said he had hyd rollers spin to 6500. I never knew if he divulged his secrets.

The drag n drive engines flood the cylinder heads to cool the springs. So with this method, one can assume that heat contributes to the failure, not necessarily the extreme valve action alone.

There are no secrets really. Engine builders, even self proclaimed, have been spinning hydraulic rollers that high for decades. Even Dave at SD if you want other Pontiac examples other than my own experiences. In fact, Dave recommends hydraulic rollers for any build up to 6500, and only recommends solid rollers for builds making power above that point. Tom even gave an example of his own Pontiac earlier in this thread spinning that high and didn't even bother with lightweight parts.

Heat for sure attributes to spring fatigue and possibly spring failure, maybe those worried should look into cryo treating, but it still doesn't change the fact that those guys also zero lash those solid rollers for the drives to help them live, so they aren't beating themselves to death, and then open the lash back up at the track. That's a pretty common practice for those guys that's been going on for years. Yet they still have lifter failures, it's just the nature of it. If they didn't zero lash for the street miles the failures would be even higher.

Why is that? Could be a lot of reasons. Could be lobe profiles they are using are a bit too aggressive for the street, after all these are basically race engines they are trying to make live. Could also be the excessive spring pressures needed to control the valve train on aggressive lobes, or a combination of both. These guys are also trying to turn those things 8000+ rpm so you can imagine how much spring is in those things. The extremes these people go through to try and pass this off as a street car.

[Dragncar]

Originally Posted by 1968GTO421

Good point. Is there anyone besides SD Performance that ports intakes? They are the only manifold porters that I know of.

Marcella ports intakes, Barton ports intakes.
Pull out the wallet and those guys will make them flow. I bet BES has a guy too.

[Gach]

Originally Posted by Formulajones

Wilson

Thats who Gabby worked for before he went out on his own. My Victor that was just port match to my heads, ( wide ports ) back to back dyno pulls Gabby’s fully port Victor made 30 more hp. But your not talking about your average pump gas street motor. SD may port intakes but not even going to close to Gabbys. And there’s a good reason why. Its not needed. Intake porting thats a whole other topic.

[Formulajones]

Originally Posted by Dragncar

Marcella ports intakes, Barton ports intakes.
Pull out the wallet and those guys will make them flow. I bet BES has a guy too.

Yes BES ported dad's intake when he did the 571

[Stan Weiss]

When looking at potential HP output. You need to look at flow for your total intake track. This means not only flowing the head with the intake manifold you are going to use, but also the carb you will be using.

Stan

[Gach]

When flowing heads through and un-ported intake theres as much as a 20-25 cfm drop. So if you think your 350 cfm head actually flows 350 though a mildly ported intake ( basically ) just port match to head, and just clean up its more like 320-330 cfm. Especially if that 350 cfm is at 700-800 lift

[HWYSTR455]

I ran an SR in a daily driver for 220K miles with only a valve job at 140k, no problems. Ran another on a daily driver for @80k miles, sold it to a member who ran it for @20k miles, who sold it and is still being run to this day to my knowledge.

And I abuse my stuff.

Not sure where all the talk about failure-prone is coming from, or high maintenance, but it's not accurate. You just have to make sure you get the 'right' parts and properly maintain it.

Parts quality is probably the biggest factor, and you take a chance with any part these days.


.

[Gach]

Some times longevity of solid roller lifter… it’s called luck of the draw.

[slowbird]

Originally Posted by Gach

Thats who Gabby worked for before he went out on his own. My Victor that was just port match to my heads, ( wide ports ) back to back dyno pulls Gabby’s fully port Victor made 30 more hp. But your not talking about your average pump gas street motor. SD may port intakes but not even going to close to Gabbys. And there’s a good reason why. Its not needed. Intake porting thats a whole other topic.

Post those dyno sheets, please

[Gach]

Originally Posted by slowbird

Post those dyno sheets, please

Nope

[Stan Weiss]

Originally Posted by Gach

When flowing heads through and un-ported intake theres as much as a 20-25 cfm drop. So if you think your 350 cfm head actually flows 350 though a mildly ported intake ( basically ) just port match to head, and just clean up its more like 320-330 cfm. Especially if that 350 cfm is at 700-800 lift

I am always trying to learn. Please explain this statement.

Stan

[Gach]

Originally Posted by Stan Weiss

I am always trying to learn. Please explain this statement.

Stan

Nope

[Stan Weiss]

Originally Posted by Gach

Nope

Thank you. I am glad that we have gotten that cleared up.

Stan

[slowbird]

Originally Posted by Gach

Nope

Figures, I'm sure your results are real. We will just take your word for it.

[slowbird]

Originally Posted by Stan Weiss

Thank you. I am glad that we have gotten that cleared up.

Stan

It's because if the heads flow 350cfm at other lifts it doesn't matter, but if it flows 350 at .700-.800 then it really matters at you lose 30hp. Lol

[Gach]

Who let the trolls out..LOL.

[Dragncar]

I don't know but is seems like statements made as factual, then avoid any proof is the troll like behavior. Not so for the people who have actually done things, and proved them.
Say it, prove it. Simple enough.
Truth and honesty is ALWAYS the best way to go in life.

[Jay S]

JMHO, but 10,000 mile out of a .3883” UD profile with 1.65s running 230 ish seat and a 500 spring rate sounds like a good run to me.

I’d expect some maintenance for that many miles. It is a 33* intensity cam, designed for more strip than street. If you want to put more miles on it with less maintenance the intensity should be more than 33*, JMHO.

Those spring rates are on the high end for that profile, set up for what you would want to run in a bracket engine with limited street time. A .3883” does fine down at 190 seat and 460 on the rate, but that is a lot of head flow, so it is understandable why it was set up on the high end.

It looked like it will be able to be reground to me. It will come back with a smaller base circle, might take longer pushrods.

[PAUL K]

Originally Posted by Dragncar

I don't know but is seems like statements made as factual, then avoid any proof is the troll like behavior. Not so for the people who have actually done things, and proved them.
Say it, prove it. Simple enough.
Truth and honesty is ALWAYS the best way to go in life.

^^^TRUTH^^^

[slowbird]

Originally Posted by Dragncar

I don't know but is seems like statements made as factual, then avoid any proof is the troll like behavior. Not so for the people who have actually done things, and proved them.
Say it, prove it. Simple enough.
Truth and honesty is ALWAYS the best way to go in life.

In this day age you can say whatever you want then cry about people asking for evidence/proof.