Should I buy these 3.2 heads?

Rot 911 · 11-20-2002, 05:40 AM

I have a chance to buy a set of complete 3.2 heads with only 14K miles on them for $800.00. The heads on my car have worn valve guides and need rebuilding. Should I go ahead and buy these heads and swap them for the ones on my car or send off the heads I now have and have them rebuilt? The heads I have the opportunity to buy are not rebuilt heads, but actually only have 14K miles on them. I don't know what year they are so not sure if I will have to worry about a valve guide replacement around 60K or not as sometimes happened on the early 3.2 heads.

yelcab1 · 11-20-2002, 06:18 AM

My opinion for things like these is:

"if I cannot be sure what has been done to the used stuff I am about to buy, I rather rebuild my own stuff."

Rebuilding your 3.2 heads should be less than $500 (unless you damaged them or something). When I did mine, I paid $320 for the valve job at the machine shop, including removing the Head temp sensor bits (that broke off) and new guides.

APKhaos · 11-20-2002, 07:05 AM

Kurt,
No question - have your heads overhauled by one of the very reputable shops out there. You get a great set of heads, new guides, seals & retainers, and have your valves checked and spec'd. Cost will be comfortably under $500, even if you need to replace a few valves [the shop will measure them and replace if necessary].

I'd go this way regardless, but would be extra suspicious of 3.2 heads that have been pulled just 14K after a rebuild. Something happened.......

Its easy wrenching, too.

RoninLB · 11-20-2002, 07:16 AM

Kurt... IMO, head work on 911's is art.. where to clean in the ports, how to install guides, etc.. and I bet at a DE it will make a difference between an artist and non-artist. IMHO, good is not good enough .............Ron

Rot 911 · 11-20-2002, 08:13 AM

Guys, thanks for the input! I'm really starting to get better about not making hasty decisions and getting knowlegable opinions first. I think I will pass on the heads and rebuild the ones I have.

Superman · 11-20-2002, 08:18 AM

When I did my rebuild, I discovered that JW does not favor reusing valves, particularly exhaust valves. John is certainly not one of those automatically-replace-everything mechanics. He is very very sensible. But he showed me the taper that had developed along my exhaust valve stems, and we replaced them, and the intake valves when we did the heads. That adds some bucks to the job.

yelcab1 · 11-20-2002, 10:20 AM

I generally agree that the head work on an exotic machine is an artist thing. However, there seems to be enough VW and aircooled Porsche 911 for the last 30 years that the 'art" has been throughly passed on. Find a good machine shop and chances are he / she will know what to do with your 911 heads.

And yea, if the valves are tapered, they gotta go.

Superman · 11-20-2002, 12:12 PM

I would also agree with the 'art' remark. JW showed me some of his method since he knows I'm a curious guy (thanks, John). The artsy part, I would say, is in dressing the seat. For example, he resurfaced the stones each time he applied them to the seat. This part takes experience.

On the other hand, the actual guide replacement was done with a hand air drill, hand air hammer, stepped drill bit, driving bit and reaming bit. The head was in an ordinary bench vise. That part took about 1 to 1.5 minutes per guide. Fun to watch.