ptuomov

This is the post-mortem for the porting and polishing thread: https://rennlist.com/forums/928-foru...ee-thread.html

For a number of reasons, most likely including the recession and less than stellar business acumen, the person porting my heads went out of business and closed his shop last year while in the middle of the job of porting my heads. This was a cluster-f of epic proportions, of course. There are multiple potential fail-blog entries in the saga, including lost parts, missing persons, etc. On the positive side, to my knowledge, the Mexican mafia was not involved.

Don't have your heads ported by Don Redmon!

Hence the title of this thread, The Head Case.

So that's the bad news. The good news is that Jim Morton really did me a solid. He (a) extracted the heads from a rather random location where they had ended up in because of the business failure and (b) completed the job. Furthermore, these heads look like they'll work out in the end. So a happy ending is in the horizon.

Some photos:

The valves are by Ferrea. Close to stock sizes and weights, but should be able to handle the turbo heat.



The springs are custom load beehives from PAC. The seated load is about 85 lbf and the spring rate is a bit above 300 lbf/inch. Because of the lower valvetrain mass and higher spring load, the simulations say the heads would be good for over 8000 rpm without valve float with the selected cam profile.

The cams that will be run in these heads are the S3->S4 cams with reground lobes, made by Dema Elgin and Jim Morton. Those are the same cams that are run in Dennis Kao's 5.0 screamer motor. Since Dennis Kao's engine made over 380 rwhp NA with those cams and shaved heads (https://rennlist.com/forums/928-foru...and-video.html), it'll be interesting to see how these cams will work with twin gt3071r turbos strapped on. I have certain expectations... ;-)



Another beehive shot. The valves have single-groove keepers that don't butt, so that connection should hold up as well.



The head castings are the fourth casting revision, manufactured some time in the early 1990's I bet.

danglerb

Looks pretty, when does it get bolted to a block?

karl ruiter

There was a well known Porsche machine shop in Pasadena, called Precision (something I cannot remember). I dropped off my heads there one a Wednesday and was supposed to pick them up Friday. Friday morning I could not find the shop. I had only been there once before to drop off the heads so it did not suprise me that I might have to drive up and down the street a few times to find it again, but I just could not find it. Finially I noticed the wisps of smoke still coming up from the now empty lot. Glad to hear you had a better result.

123quattro

Tuomo,

Glad you got your heads back. Sucks about the original work. What kind of head gaskets are you going to use?

BC

Can you pust some info on the retainers and keepers? They do not look stock.

BC

I can see that the exhaust ports were changed slightly. Does Jim Feel that the exhaust port needed more volume because of the increased flow from the cams? Can you state whether the intake port was enlarged or simply smoothed on transitions, etc?

ptuomov

Best case this weekend.

I guess they bolted your heads on, and the engine become so powerful that it was able to move the entire building thru time, a little like this:



Stock Porsche thick gaskets, since it's the stock 100mm bore. For this engine, everything is relatively conservative, so no heroic experimentation with MLS or anything like that. Saving those mistakes for the next round!

The tiny retainers are half the trick in the beehives. The springs and retainers are mod Ford beehive springs from Peterson American Corporation with custom reset load. They are steel retainers, but since beehive allows them to be small, they are AFAIK lighter than dual spring titanium retainers.

The grinding job itself was done by Don, everything fell apart only after the heads were almost done. I think the end outcome is quite reasonable, but who knows?

Jim Morton

disclaimer... I had nothing to do with the porting or chamber work on these heads. I "rescued" them for Tuomo and had my shop complete the valve job, check install heights and did the deck work.

The porting work was done by Don a while ago and I think Tuomo posted his flow results. IMHO, the porting work looks very basic and I would have concerns about the exhaust porting if this engine were going to be run normally aspirated.

ptuomov

Jim -- Thanks for saving those heads. Indeed no good deed goes unpunished if you have now become associated with Don's porting work! ;-) Best, Tuomo

Yoakim Larson

Tuomo are you going to do the GTS exhaust mod, I notice you have two out of four hole drilled.

ptuomov

Yes, those were just drilled and now match the new-style gaskets.

BC

Meaning....that they are augured out too much?

slate blue

Hi Tuomo are you going to show pics of the ports?

Cheers Greg

ptuomov

Those photos are in the porting and polishing thread.

Rick Carter

What are the part numbers for the valves, did you do anything with the valve seats?