Does which head goes on which cylinder matter?

[axl911]

I sent my heads out to be worked, but when they come back there is no marking on what cylinder they belong to. How important or is it required that the head must be matched back up to its original cylinder?

BTW, this is a 964 3.6.

thanks,
anthony

[WERK I]

Nothing stamped around the intake port areas? First time the engine has been torn down?

[stevepaa]

Doing mine also. I marked mine, but I believe it is not necessary. They should be interchangeable.

The important pieces to mark and keep track of are the pistons and cylinders.

[axl911]

Nope. Nothing stamped or marked. I marked them when they were sent out, but the cleaning took everything off.

[stevepaa]

Yeah, I marked my heads and cyliners using a dremel tool and made notches in the fins and scribed a number on the top fin. Any type of nond-destructive mark gets cleaned off.

Just kept the pistons separated and arranged as they would go back in.

[ChrisBennet]

Part of what the machine shop does it make the heads all the same. It shouldn't matter where they end up (except for a 993 I guess).
-Chris

[Determined]

I too had the same problem, I used a mechanical pencil and after cleaning it was barely readible!!!@## What about the wrist pins to Piston, do they need to be matched? I just sent out my pistons and wrist pins for thermal barrier coating and I hope they don't get mixed up.

Alex

[magic930]

The piston and wrist pin does matter since their weight should be balanced.

[Determined]

Thanks Majic 930, I took extra precautions to make sure they remained matched while being treated.

Alex

[snowman]

Matching the HEADS does NOT matter, period. No moving parts are associated with the heads per say so it simply don't matter.

What does matter is wrist pins and pistons, they must be kept togather. Pistons and cylinders should go togather if used pistons and cylinders are used. Lifters and camshafts definately MUST and it is a very definate MUST stay togather. But heads, no moving parts so whatever.

[jimbauman]

Well, I don't know if it really matters or not, but I made a note of the casting numbers on my 3.2 heads. The combination of numbers made ID easy (6 unique combinations) so I could put them back where they came from....

[snowman]

If you do not recondition your heads it might matter, as it never hurts to put things back where they came from, but if you recondition your heads and case, they should all be exactly the same thickness and there is no other thing to match. Any wear pattern is erased. The only wear is where the cylinder wears into the head and case and if there is much of this they must be reconditioned anyway.

Basically the rule is that if original parts are reused and not reconditioned they MUST go back where they came from, but if they are reconditioned or replaced they can go anywhere. Mating parts such as lifters and camshafts must be reconditoned togather else you get problems. If you reuse pistons and cylinders, even with new rings, they must go back togather they way they came apart. But if you were to use new pistons or cylinders or both they can go where ever you want.

Actually a properly remanufactured engine should allow you to put the parts where ever you want to as they are all like new and have all wear patterns erased.

For example when I recondition a cylinder head, I recut the mating surface, replace the valve guides, recut and or replace the valve seats, regrind and or replace the valves and finally match all heads to each other. They can be used anywhere.

In my opinion an engine should never need "freshing up" ie just replace the rings and bearings. If it was properly built and used in the first place it will be worn out and need remanufacturing, not refreshing. IE if the rings and bearings are worn out everything else should be so worn that they need replacing as well.

A properly built S engine should last approx 150.000 miles
A properly built T engine should last approx 300,000 miles and an E engine somewhere in between.

A properly built Race engine should last 30 hours and finally a properly built RSR engine should last for maybe 50,000 miles. If they last longer they are not producing the proper ammount of power and you will never win anythng racing. OR you need a better engine builder.