So my engine builder and I somehow didn't communicate real well.  Somehow it was assumed I had 95-100cc chamber heads. Well I am really just sitting at 75cc.  So my compression jumped to 13 to 1. No bueno. Can't afford to run racing fuel. So I am wondering how much I should sell them for?  600? 800? 1000? 2000? Kagillion? No clue. Any help would be appreciated.  Just had them both gone through for 400+ dollars, so they are ready to rock.........just not on my engine. Thanks


P.s. Don't know a whole bunch about them unfortunately which makes it hard to figure.

Have they been excessively milled to reduce chamber size?

What is you quench distance?  Can you run a thicker gasket without exceeding .055?

What pistons?  Do they have domes that can be milled?  Can a dish be turned in them?  Pics of top and bottom would really help.

Heads are aluminum?  What cam / exhaust?

Maybe we can save this.   Smaller chambers can equate to a lighter piston.  Would it be better to get new pistons and keep the heads?  A dished piston will make more power than a flat or dome.

Just trying to find alternatives.

Joe

What kind of valves are in them?  What size are they?  Springs for solid, flat or roller? Do you have specs on the springs? I might be interested if you decide to sell

There are some things that you could do to bring your engine back to a more pump gas friendly static and dynamic compression ratio.

First, you really need to know what your REAL static compression ratio is.  EVERYTHING needs to be measured.  Wish you weren't so far, I'd help you measure everything out.

Some things that I would investigate with your machinist would be:  unshrouding the valves to the gasket edge along with "eyebrowing" the block to match.  I would cut valve notches in the pistons to clear a larger cam so you can upgrade now or in the future.  I would radius every sharp edge on the piston crown.  Those valves will tolerate a bit more dishing on the face.  I would put a lot bigger (more duration) cam in it.

All of these will lower static and/or dynamic compression ratio yet actually make more power.  If you have to pay for this work to be done, you will need to decide if it is just more cost effective to get a new set of heads.

Let me know if I can help,

Joe

The only way to make those heads pump gas friendly is to get a dished piston

And here is my beautiful mistake

The heads are really just a copy of the for cj head..There are better options out there. ..even the 95cc edelbrock heads flow better. .that is what I have now..Paul Kane set them up for me..so if you have him In the loop you will not be misguided

Well the heads are sold as of an hour ago.  Simple enough.