urban_cowboy

This is the second time I have had rocker and valve problems. I am not really sure what caused this. I had a bad bout with running rich before I threw the double pumper on the shelf and move to an HP. Maybe preignition...I dunno. Pinging was never very bad. I am done with these aluminum comp cams rockers. I may try their roller steel rockers and am investigating Jesels. Half of #6 was laying in between two springs. I found a few needle bearing, but there much be a bunch of stuff in the pan. #7 push rod is totally stuck in the rocker. #4 and #8 look about the same. The other may be cracked, but are not obviously broken yet. I have no idea how long they have been like this. The funny thing is it never made any strange noises. How I could tell something was up was I found oil in the driverside tail pipe (I guess from no combustion in some chambers...no intake opening), then low compression in some cylinders, then really strange tuning problems (low vacuum and richer AFR), then low power.

Kotobuki

Jesus, man. Does anything ever go RIGHT with your car?

That said, and just as a thought... You're running a high power stroker? With I assume a pretty tall cam, and then a 1.7 rocker on top of that? Which means you're probably running way heavier springs than any (even close to) stock application?

If all that is correct, I'm not entirely surprised to see you chew through aluminum rockers. I'm no metallurgist, nor a mechanic, but I'd definitely think a steel rocker would be the far better choice.

urban_cowboy

Yeh, there is not data on what you should and should not run the aluminum rockers with.

I am running a cam with .3810/.3850 lobe lift. With 1.7 rockers, that is .6317/.6365 actual valve lift considering valve lash. The springs I am running are AFR's roller springs. I cannot quote you the specs, but they are in the 210 seat 520 open range. The stroker is built for about 500ft*lbs of torque which is a fair amount, but nothing in the motor is real radical. Heck, I could easily be running another couple hundredths valve lift with a different cam.

Totally frustrating that I keep breaking stuff. I just cannot get things strong enough to last more than a few thousand miles. I think I have less than 2000 miles since the last valve train crater.

Adrenolin

I decided against the aluminum rockers early on and went with the CC Pro Magnum roller rocker. These ones. Aluminum simply aren't as strong or lasting as steel. Sorry to hear about your continued problems.

urban_cowboy

The CC Pro Mag rockers only come in 1.6 ratio, which is one reason why I went with the aluminum ones. The HiTech Stainless come in 1.7, but I am not sure how they stack up in strength.

Jesel rockers KSS-517070 cost about $900 as set. Harland Sharp aluminum rockers are about $375 a set. Harland Sharp shaft rockers are about the same as Jesels $950 but are still aluminum. I am leaning towards going away from aluminum rockers, but my racing buddies use them with out issue. They do switch they out every season though, which this is street rod, so it gets more abuse.

Starfury

Ouchies=/ I agree, though, comp Cams' chromoly rollers may be the way to go.

As an afterthought, what about shaft-mounted rockers?

Adrenolin

The Pro Mags do come in 1.7. All you'd need to do is tap the heads for 7/16 in. studs. Seems to be the cheapest route to go yet give you the chromo steel for strength. Just an idea.

urban_cowboy

I do have 7/16" studs. In looking at the CC catalog, the only Pro Mag rockers in 1.7 are the ones for 351C. I am not sure they will fit geometry wise with a Windsor...

Adrenolin

I'd call CC tomorrow and ask them. From what I see the specs are the same for both the 1.6 (W) and the 1.7 (C) with the exception of the ratio.

JMD

After two experiences I would have to be wondering if maybe the rockers might be "bottoming out" against the studs...

If the edge/lip of the rockers come close to the stud when cold, the lenghening of the valve train when hot might be enough to push the assembly over the edge...

Slightly shorter push rods MIGHT be the order of the day...