Mechryn

I'm in the middle of a HC swap on my 97 vette. I have a set of MTI Stage 2e heads milled .020" and an MTI X1 cam. I have the cam installed and the front cover/underdrive back on. I put one of the heads on the car with the old head gasket and old head bolts. Installed my 7.4 pushrods on cylinder #1 and installed the factory rockers. I turned the motor over by hand several times and everything went around fairly smoothly. After removing the head I saw "eyelash" marks on the piston top. I called MTI and they said no way I should be having interference. So searching around here I have seen where some guys are having trouble with PVC and these heads and cam. (example: last post in this thread. https://ls1tech.com/forums/showthrea...ighlight=stg2e) Any advice on things I should be looking for that would cause the interference? Should I expect to have to flycut with this setup?

TIA

RZRSEDGE

iTrader: (21)

Are you sure that it is in exact time? Not trying to insult your intelligence, just trying to get the obvious out of the way.

Mechryn

Yeah I installed the cam. Had two friends double check it. Rotated the crank a couple times after the fact and the dots still lined up. (Every other time of course.)

Mechryn

I need some help!

098z28

iTrader: (12)

dots are touching eachother right not each pointing straight up??

PREDATOR-Z

Flycut, .060 intake

Mechryn

Yes the dots are lined up. Cam down. Crank up. Thats alot of flycutting. If i had a set of heads with no milling would I need to flycut as well? I didnt think flycutting was required with an X1.

PREDATOR-Z

If those are 5.3L milled .020 so they are ~59cc so that is why you'd be running into issues.

.060 flycut is not even 1cc, it is like the depth of a nickle coin.

Mechryn

They are 241 LS1 heads.

PREDATOR-Z

Ok 241 heads milled .020, so that is like 3.4cc
What size valves do you have in there?

Still it should clear, did you check the cam install? dot to dot

Mechryn

Stock sized valves. Cam is installed correctly. I am questioning how legitimate the cam is. It was given to me by a friend. I'll pull it back out tomorrow.

PREDATOR-Z

Ah sooo, it could be a much bigger cam, that makes sense.
You should get it doctored to find out the full picture.
Might be somethhing worth a little flycut?