rickyb

In order to minimize downtime and assuring that heads with more miles don't get out on my low mileage car, I have started to plan. I know I will have AHP do the build with Moldstar 90 guides. My question is has anyone shipped them brand new heads from GM? Bad idea? I would sell my existing heads to recoup some of the expense. Does this save any money when you send to AHP?

Unreal

Zero reason to do that. Mileage on heads doesn't matter at all since they replace all the wear items. It doesn't matter if you have 200k cores or 10k cores. They make them like new.

MTPZ06

They typically have core sets in stock ready to go to minimize downtime. Your core charge is refunded when you send your old set back. No need to overthink this...

User Omega

This ^^ Just call Kohle to find out what he has right now.

RichieRichZ06

As others have stated, Kohle at AHP typically has sets of heads ready and can send them out without you sending cores in first. I've had a few customers do as you stated and purchase a new set of heads first, but there is not much benefit to that because most of the parts are being replaced. If you still want a new set of heads, let me know as I have a couple sets available at a discounted price compared to typical forum pricing.

RICH

spy2520

If cores aren't available I'd buy used heads before new ones.

rickyb

Really? How come?

Dirty Howie

Eh ........... get the new ones. Then the guides could be measured and see if GM can get two new heads machined within spec

And you could give Rich some business


DH

Turbo2L

It's a waste of money?

American Heritage

We have core sets in stock and ready to rework to your exact specs!!!

All our heads be it new or used will meet the exact same standards/specs by the time we are finished processing them. In other words it does not matter if you start with a new or used set of heads. If you much have a new set of heads we recommend purchasing from Rich above (RichieRichZ06) and having him drop ship them to us. We have had several sets of new heads drop shipped to us in the past.

hp@americanheritageperformance.com
or
310-326-2399

http://www.americanheritageperformance.com/

stefuel

Me, I'd take a 100K used pair of stock heads to do over new. The older castings have been heat cycled countless times and if they were going to fail would have done so a long time ago. Resurface, new seats, guides, valves and call it a day.

LawrenceFromTorrance

I've thought about this and have a question. If the valve guides were manufactured badly (wrong angle, etc.) how does replacing things fix this problem?

Michael_D

If you bought new, then you'd know the valves have not been stressed under a potential condition where the guide clearance was very high, or seat concentricity was way off (or both). In either of those situations, valve life could be compromised.

injfuel

So your saying if those 2 conditions were present on a used set of heads there's no way reworking them could rectify those issues ?

American Heritage

He is saying that if the heads were run for substantial time with out of spec clearances, bad concentricity, ect... You could have valve wear. With that being said we measure all our incoming core head ti intake valves and closley inspect them for damadge, ect... We do not use worn valves that do not meet our specs. Any valves that are worn or damadged get tossed and replaced with new ones.
We then do our treatment process on them and that makes even an older valve better than new.

All are core heads and components meet our standards before we start processing them/accept them as cores.
With our core heads you are assured to get better than new components and a better than new final product.

outhouse

Its not a bad angle.


When the guides were machined for the valve, they holes were not perfectly round, AND the guide material softer then it should have been.


Valves not polished as well as they could have been.

Michael_D

No, I am not saying that. I am saying the valves may need to be replaced, which would add costs. The stem itself could have stress cracks, in addition to the valve head. It's just a risk to consider.