Has anyone ever has a set of 16 valve heads done? Can any performance shop do it, or does it require a 928 specialist? I have a 5.0 block and stock 81 heads in the 79. When I pull the engine I would like to have a mild valve job, any power there on these engines? What did you pay and how far did you go?

Thanks!
BB

 

I had the heads re-done on my '80 Euro S. A local auto machine shop did the work, nothing special to them. As I recall (vaguely) it was @$1k including valve seats and seals. Good price from a shop that does Chevys...

Unless your '81 is modified, it probably has a 4.5L block or a 4.7L block if a Euro S. Euro S heads would flow better as they have bigger valves than US heads for that year.

 

Ive also had a local chevy shop do heads on Porsche before, nothing to different to them. I think it was $3-400 hundred a head or so for a full work up, and Im sure I got 1.36 hp from it too!

 

I just had a set of Euro S heads gone through. Cleaning, decking, stem seals, and fixing 2 broken exhaust studs was $400 in labor. They are nothing special. Anyone good with small blocks can work on them. I asked about porting. He said they looked good for stock and it would be a waste of money unless they really went to town on them. They also commented that the exhaust valves were too big.

 

So, if porting Euro heads would be a waste, porting a set of 81 u.s. heads to Euro specs would be beneficial? This car does have a 5 liter block.

 

What is the Block ID? OOPs you said it was blank, eh, why do you think its a 5.0 instead of a 4.5?

Porting a set of early non Euro S heads is a very expensive way to get slightly less performance than a set of Euro S heads has stock.

Putting an Early CIS Euro or Euro hybrid in your car would not be much of a chore or expense. If you are thinking more power, you should be thinking about it prior to screwing with the 4.5L motor.

If you are sure you want to go the 4.5L with headwork route, send me a PM I know someone that may still want to sell a complete motor with all the work already done.

Mark Anderson posted a place last week.

Engine Supply
304 E Dyer St
Santa Ana Ca 92707
Mike 714-556-0310

Ausil bore $350
4 valve head $105 (guides extra)

 

Most likely you will need new exhaust at least, I have had more of these 2V heads ported than most, a clean up job shouldn't cost too much and is well worth it. It costs me $150 per set for this work. It has been flow bench verified and the ports are NOT enlarged. If you can afford it fit the 49 mm intake, this is also worth it at around $250 including seats genuine, just have them blended in around the seats and a nice throat created.

My reco heads (not counting new springs) were around $500 and had 16 new guides, fully serviced, decked etc. If you don't have confidence in their port work don't let them do it, they can make it worse. My 0 - 100 mph time is in the 10 bracket, 0 - 125 is 16 seconds.

Greg

 

I spoke with the original owner. Also have receipts from a Porsche performance shop (Andial) that show a brand new 5 liter block was installed back in 87 or 88.

What makes the Euro heads so much better? These can't be replicated with non Euro heads?
Which route should I take? I'm more than likely anticipating a cent. type supercharger and would like the heads to compliment the system.

 

Cost of head work. In South Park you can get one for $5.00. I'm not sure how much for a sucky sucky in CA.

 

5 bucks? That is so sad to think about...

 

I don't think that would be a three angle job.

What I saw of the paper work was more confusing than informing, so best to rely on measurements and casting numbers.

Short answer is that Euro S heads were designed by Porsche to support 310 HP. As cast at the factory the ports are the right size and shape to make that kind of power. The non S heads are not, and there is only so much metal that can be safely ground off to enlarge and reshape the port.

The practical answer is that in the early days plenty of people did the best they could porting the early non S heads, and the results fell short of S heads with the slightest of porting if not stock. More than a few porting attempts got worse.

As it sits now, Euro S parts are cheap, $1000 to $1500 for a whole motor without that much looking.

****************** What should you do?
I kinda liked the idea of the Mod motor swap.

What I think is the best most practical increase in power would be a Euro hybrid motor.

I don't see a cent. blower as a practical option in Calif period. Too much hassle taking it off every two years for smog inspection, and too little increase in power on a 16v motor.

 

Thanks Mike, once again - exactly the answer i was looking for. Now I know the difference between the two head types. Thanks!

 

I would try and source an entire 4.7 Euro engine. Heads/cams go for nearly what the whole thing costs.

 

Its like the old lady that swallows a fly, a complete Euro S (with some kind of problem) often sells for the same as a complete motor. Thats what happened with the last guy that I was trying to hunt down a motor for, he found a whole car cheap and bought that instead.

 

On Carl's site (928 Motorsports), it's $825 for port/polish on a 16 valve heads. Multi-angle valve job is $425.

When I did my heads on the 84 a couple years ago, it was $600 to plane and seats/seals and fill in a small spot of corrosion.

It was the cost of all the other crap of "while I'm in there..." that made the project expensive and time consuming. I.e., belt, water pump, rollers, gaskets, fasteners, vacuum lines, hoses. In my case, it was a blown gasket. My take away from the whole event was change the radiator fluid every 2 years and never use any kind of radiator/head sealer.

/ Bruce