V4 shaved heads with marks from the piston?

[rjdubiel]

I got these heads with the viper. They are the tight heads that Jeff had but never ran I think. The guy I got the rig from never used them also from what he said. I was looking at them the other day when moving crap into the new garage and saw there were some marks from the piston contacting the head it looks like. I am told these are 1973 135 hp heads. I have not checked the numbers on the heads to what motor they really go to but it looks correct. Will find that out when i get home but my question is could someone who shaved these have taken off too much material causing the marks from the pistons? How does someone measure an acceptable clearance between the piston and the head?
http://i64.tinypic.com/15z5oih.jpg
http://i67.tinypic.com/2reryxd.jpg
http://i68.tinypic.com/2lu9cae.jpg

[EMDSAPMGR]

I have a set of heads from a V6 crossflow that were shaved too much. When I installed them without the head gasket, the pistons hit the head when turned by hand. The marks left were at the outermost edge of the dome of the piston and left slight marks on the outside of the heads. This is not what I'm seeing in your picture.

[racer]

I agree with Ed. You need .041 clearance if the clear without the gasket you have .050 or more, You can use solder with gaskets thru plug hole and rotate engine by hand to crush solder then measure for clearance.

[rjdubiel]

I wonder what made these marks then? Thank you for the replies, much appreciated.

[Freddie Webb]

My guess would be a cleaning/cutting tool on an air grinder. While cleaning the heads up but that's just a guess from the pictures. It's hard to tell.

[BarryStrawn]

The marks that form rings around the spark plug holes could be from a washer where someone bolted them down to a mill table.

[rjdubiel]

Barry, that has to be it! never though of how they hold the head in place when surfacing it. Is this a common practice as I do not know?

[99fxst99]

The marks that form rings around the spark plug holes could be from a washer where someone bolted them down to a mill table.

That's exactly what they are. Done it many times.

[BarryStrawn]

Barry, that has to be it! never though of how they hold the head in place when surfacing it. Is this a common practice as I do not know?

Yes, it is a common way to clamp them. Although maybe not with steel fender washers or whatever did that. I turned a set of step washers from aluminum to avoid any chance of damage.

[racer]

Piston cant touch in that area as would hit squish way before. The area to watch is on the exhaust deflector, the radius on intake and squish. Good catch guys I only looked at what mentioned.

[rjdubiel]

Thanks again to all. Numbers on the cut heads indicate these are '73 135 heads. May have to bolt these up next year and see if it helps out my holeshot as that is where I am needing help right now.

[EMDSAPMGR]

When you install those high compression heads, I'd be jetting the mains up in the carbs to keep the combustion chambers cool at WOT.

[Umassot50]

The compression will be about 165psi on a gage as well. Good fuel required.

[bogiesworld]

Going to need more than that rj!

[rjdubiel]

Going to need more than that rj!

We will see. AnU thing in the works for that yamaha?

[bogiesworld]

Top secret! Merry x mas my friend!

[bruzercomp81]

Rj they make different thickness head gaskets if they hit. I had the same problem with my nos ccc heads. With the thinnest gaskets they hit and at 7000 rpm they left dents in the pistons but didn't do anything to the heads.