what's the old saying? "better safe than sorry"?

 

It's hard to argue against the mathematics when it comes to engineering ... I'd like to know how the pistons made the jump.

Andrews *did* publish piston clearance warnings for '84 to '86 Evo, including the EV27.

What the warnings said, was
So they were advising notching the pistons which would be cheaper than buying new ... except we have Ebay nowadays.

For me, often "the devil you know is better than the devil you don't", i.e. stick with the original 'known good' pistons unless going for higher compression.

 

Well it just keeps getting better, I would like to get my **** back from Indy so I can measure up with my pistons , .045" gasket ,27 cam and see what is what. John says definitely valve will hit, one way to find out. So I think I will not buy pistons just yet.
Install pistons with out the rings, no base gaskets, install head gaskets and heads with two snug bolts, measure valve travel without the spring installed ....this the best way ????

 

Aaaahhhh, I see you made an edit to include the ev27 not sure where you read it, I didn't notice on their site, but I believe, so much for my last post then,I'll be buying pistons from the stealer I'm sure, stock $180.00 pair(kit).

 

If John says they will hit then they will hit.
I ain't seen him be wrong yet!!

 

You might want to go 10 over to make sure.
Granted you will have to get the jugs to 10 over but it is best to have a machinist get them to match.

Just a thought.

 

Meaning ? Bore the jugs .010" over instead of just honing ??

 

I have not see any one on any Andrews EV27 related page either ... but I did find one on a reseller's website, so I included it. But I think I was wrong to.

Perhaps I should have written "might have" as it's not possible to know if that was from Andrews, or just off a template. I think it original came from a Custom Chrome catalogue, e.g. they also use the same disclaimer for Crane Cams. It applied to all cams, not the 27 specifically.

http://www.powersportsnetwork.com/en...tCategoryCode=

Powersportsnetwork are CC resellers ... but same caveats apply to them.

Engineering is ultimately determined by some very old fashioned, simple and reliable mathematics. You can't just assert they might, and worry, you've got to show how. Or how not. John know this. Those are 'good enough' figures I gave you. Again, I encourage to measure your own, not worry, and not spend money you don't need to.

I still say something else must have been going on for contact to happen; skimming, pistons, rod adjustment, thinner gaskets, over revving ... something to fill that considerable gap. It has to have had.

 

Whenever you get new pistons you have to get the jugs machined to match.
If your jugs are worn enough then the stock ( 0 over) pistons won't seal right.

What ever shop you use they will need the jugs and pistons to make sure they match correctly.

 

Gotcha, they have had them long enough already, six weeks !!!!!
If something doesn't happen soon, I'm getting them and sending to Hillside like I should have done.