Cap walk on A460

Talked to guy that engine builder found signs of just a little bit of cap walk during bearing inspection on high reving 500" BBF. Have any of you seen this before

Yep, Keown's old engine had it. Excessive timing and high RPM's...It can be done if you try hard enough

The caps can't really walk around because they're pinned however, some metal transfer can still take place if they bounce or excessively vibrate.
Detonation is the usual culprit.

I guess that's like walking in place,stepping without moving.

If you are speaking of Terry's engine......Phillip and I looked at it saturday.......there is no issue.

56Tbird wrote:I guess that's like walking in place,stepping without moving.

We called that marking time in the army, I believe it is treading water in the navy.

My stuff never makes enought power to have cap walk. Not yet........

Lem Evans wrote:If you are speaking of Terry's engine......Phillip and I looked at it saturday.......there is no issue.

Actually looked at that block on purpose because of the high rpm and it looked awesome. No concerns at all.

^^^^^^well there ya go.............no need for concern folks................

What rpm level are we talking here?

everything has its limit ...... its racing guys

cap walk is never an issue to me.when they stop walking and start running you have a mess!

I've never seen it on the three center caps, but I've sure had issues on the two end caps. The problem... too lean/too much timing (mean tune) and RPM.

Bret

Bret Powell wrote:I've never seen it on the three center caps, but I've sure had issues on the two end caps. The problem... too lean/too much timing (mean tune) and RPM.

Bret

Bret,can too lean cause it.i can see the timing causing it but can too lean,alone,cause it.

With 15+ to 1 compression and 8500+ rpm too lean can cause some pretty serious detonation no matter what octane fuel you run. So to answer your question... Yes. This is truck pull stuff with iron heads. Which I think the iron heads can also contribute to the problem for the fact they will not pull the heat out of the chamber like aluminum heads will.

Bret

Bret Powell wrote:With 15+ to 1 compression and 8500+ rpm too lean can cause some pretty serious detonation no matter what octane fuel you run. So to answer your question... Yes. This is truck pull stuff with iron heads. Which I think the iron heads can also contribute to the problem for the fact they will not pull the heat out of the chamber like aluminum heads will.

Bret

thanks for the info Bret.good to know.