Crower, Power Level 5.

[Tom68]

I take it these are aggressive lobe profiles. Youtuber Golds garage used a 220H226 which I assume is a mid 90s 00256.

That would make it a lift rule cam, explains the aggression, Crower lists it power level 5 (titanium valves etc) is there really such a thing as a hydraulic flat tappet that small (300 lobe lift) not to mention short duration requiring light weight valve train ?

Is the light weight valve train recommendation just an effort to keep the valve spring rates down to a level that the lobes will survive ?

Golds ran standard weight components with light springs and looks like valve float at 5300.

[rgalajda]

I take it these are aggressive lobe profiles. Youtuber Golds garage used a 220H226 which I assume is a mid 90s 00256.

That would make it a lift rule cam, explains the aggression, Crower lists it power level 5 (titanium valves etc) is there really such a thing as a hydraulic flat tappet that small (300 lobe lift) not to mention short duration requiring light weight valve train ?

Is the light weight valve train recommendation just an effort to keep the valve spring rates down to a level that the lobes will survive ?

Golds ran standard weight components with light springs and looks like valve float at 5300.

Any flat tappet camshaft that runs lighter spring rates will survive longer. Light weight valve train is always a plus . Beehive springs address both pressure and mass.
Beehive springs almost always require less seat pressure and about 15% less over the nose, resulting in almost 1,000 rpm more before total valve train crash.
Tight LSA cams such as this cam with 108 LSA do not require as much duration .

[6.50camaro]

I take it these are aggressive lobe profiles. Youtuber Golds garage used a 220H226 which I assume is a mid 90s 00256.

That would make it a lift rule cam, explains the aggression, Crower lists it power level 5 (titanium valves etc) is there really such a thing as a hydraulic flat tappet that small (300 lobe lift) not to mention short duration requiring light weight valve train ?

Is the light weight valve train recommendation just an effort to keep the valve spring rates down to a level that the lobes will survive ?

Golds ran standard weight components with light springs and looks like valve float at 5300.

I watched that yesterday. Crowers catalog lists peak power @5500 for a 350. They don't show duration@ .200 lift to see how aggressive that cam really is. It is in the section for lift rule cams though is it not? The springs used were close to what Crower recommends but came on the marketplace heads, Brand unknown and who knows what quality they are.

[Tom68]

Gold measured a spring but if they were new they would have lost free height on warm up.

[6.50camaro]

Gold measured a spring but if they were new they would have lost free height on warm up.

Just went back and watched the video where he checked the springs. They are about 15 lbs light of force on the seat and 50-60 lbs light open from the spring Crower recommends for that cam.

[Tom68]

Begs the question, hydraulic lifter, unless they were running them topped out the lifters would have pumped up. Hard not to notice.

[Tom68]

Double post, server timed out.

[Tom68]

Hmmm, I asked on Youtube if the SR's with the soft springs made more torque than Mikes ported heads, they didn't, so no prizes for guessing the results with shimmed valve springs.

SR heads.jpg

https://youtu.be/BS-fKiwh2Sc


The SBC's achilles heal was Cylinder heads up until the 90s and even then anything half decent was an expensive exercise, we're blessed for choice these days.