Rebuilding a 962 motor

[edevinney]

FWIW, it looks fine on my windows box, under AOL Explorer or IE.

Still drooling, too :-) Thanks for the pics, Helidoc.

[Alan Cottrill]

if you don't want to scan back and forth to read the text, you can copy and paste it to Word, or whatever word processor you use. this will give you nice margins and an easy to read page.

[helidoc]

Ok, here are some more fotos. There are some before and after pictures of blasting the heads with walnut shells, close up of the valve guide inserts, checking for crankshaft straightness, pistons cleaned and finally of the missing squirter in the cam housing. I will try a carriage return after each photo.













He is apparently about ready for zyglo.

[helidoc]

One more picture showing the testing for leaks in the cylinder head jacket, one thing most of you guys won't have to worry about.



Good night and enjoy.

[Carrera3.5L]

Heli,

70.4mm crank or 74.4mm crank?

I think you stated earlier that you had 95mm cylinders/heads. The 98mm heads/cylinders are apparently very rare (I don't know if these ever made it into a race engine) as Andial was testing various combinations during the "off seasons" with a mule motor. Porsche in Germany was probably doing something similar. Neil told me that the increased bore didn't do all that much and that aspect of the project was more or less shelved. To be honest, I don't remember that part at all. I remember lots of camshaft profile testing and Neil working on the electronics end.

When IMSA finally succumbed to Alwin's lobbying to try and be more competitive against Nissan, Jaguar, Toyota, etc at the tail end of GTP, Porsche was allowed to increase displacement from 3.0L to 3.2L. Both a bore increase and stroke increase were tested before choosing stroke to enlarge the motor. This helped the low-end torque (which the 4-valve water-cooled motor lacked in comparison to the earlier 2-valve air-cooled version) and could help get the already downforce challenged 962C out of the corners quicker with less effect of turbo lag.

You could really see a noticeable difference between the 962C and the Chevy Spice with its thundering V8. The Chevy would pull away out of the corner and the 962C would reel it in on a long straight as believe it or not the 962C motor made plenty of top end power. Unfortunately, there were lots of street races in those days which played to the Chevy's engine (and other's with better chassis') strengths. Fortunately, the Chevy teams had a tendency to retire with engine problems (many times overheating and cooking the motor). The Corvette GTP was notorious for that. Blazingly quick in practice/qualifying/beginning of the race but nobody ever worried about them because you knew they were going to retire. That could have/should have been a dominant car if they ever could have gotten some reliability out of it.

Out of curiousity Heli, do you ever see or compete against the Corvette GTP's in HSR or other events? I wonder if they are in private hands or in GM's museum? Sarel Van der Merwe (sp) was their lead driver when GM was doing a factory effort and were in Goodwrench "Dale Earnhardt" livery and was quite quick. He also wasn't too shabby in 962's.

Ralph

[helidoc]

Ralph:

I am not sure sure what crank I have. I'll ask Neil when I get a chance. Interesting history, something I wish I could have witnessed first hand. Unfortunately I ran the car in Porsche only forums and HSR events were unknown to me when I last drove the car on the track (1998). Maybe sometime in the future?

[Carrera3.5L]

Heli,

Eric called me today, he is sorry he missed you the other day but he was in Germany for a little R&R before the silly season (i.e. Daytona) makes a vacation impossible. Based on some of your comments regarding your visit to PMNA, it appears that you may have received some incorrect information and Eric wishes that he would have been there.

The reason that PMNA won't sell some parts is their scarcity. A lot of the parts just aren't available any more. Eric is going to many of Porsche's suppliers and having the parts manufactured now that the factory has discontinued them.

You can still ring him if you want, but he does know now that you are working with Neil. They don't exactly see eye to eye and one will bad mouth the other. Me and a couple of other guys were always the buffer between them through the years.

I know Neil well as a business acquaintance and Eric and I do have a friendship and socialize together. A word of advice: I wouldn't ask Neil to get info from Eric and vice versa.

It would be really cool to get a GTP reunion together for a weekend, don't you think? A slew of 962's and 962C's, the Nissan's (GTP-ZXT & NPT-91, the Toyota Mk2 & Mk3 Eagles, the XJR V12 & twin-turbo V6 Jaguars, the Mazda 787B rotary, Corvette GTP, Ford Mustang/Probe GTP, the Spice chassis with Chevy/Pontiac V8 power. And that's just from IMSA! C'mon old timers, who else am I missing?

Ralph

[helidoc]

Ralph-

I would be game for a west coast reunion. Understand about the politics and would like to stay clear of them. I just want to rebuild my motor.

[helidoc]

Here are some pictures of parts undergoing magniflux and zyglo processes. Neil hopes to have all the checking done by xmas and then hopefully I will know where I stand.

[Don Settergren]

This is the sexiest post on Pelican!

Wow, I just found and read this post from the beginning. It took a while, and completely halted any productivity here in my home office; however I feel as though I have entered an enriching and fantastic journey. Thanks for allowing my to be a part of this historical event.

[BReyes]

The internals look very nice. This race car must be very very fun to drive, especially at its limits.

We'll be looking out for you in '06.

Good luck.

[makaio]

I just found this thread, and I just wanted to say thanks for sharing.

[helidoc]

Just an update but no pictures. Everything has been inspected and for the most part there are no major suprizes. Everything appears to be as one would expect for this type of motor. As far as the heads go, all of the valves are reusable which is good since I can't get any more. The recommendation is to go with a smaller valve stem and guide if you need to replace them. I will have to replace one spring which was not fitting flush on the seat. I debated about having Neil modify the heads in which he machines off the cylinder and then makes his own with a sealing system on the head side like on the 911. However, my cylinders were apparently with in acceptable out of roundness as good as new ones were with the exception of a little wear. The case will need either a line hone or bore, yet to be determined and that will influence whether I can use standard or +? size bearings. These bearings apparently will not be an issue to find. The crankshaft will be polished. It was straight and had minimal wear issues. The real problem is in the rod bolts and bearings. The rod bolts (titanium) are not available so we will either have to reuse them or get new rods and machine the crankshaft to fit a smaller size, more readily available bearing. We are checking into whether or not maybe ARP could machine some new rod bolts up. Neil has not seen them break before but it has been the standard practice to replace them like on the regular 911 motors. As he puts it, Porsche is in the business of selling parts. If any of you might have another source of titanium rod bolts let me know. The bearings are also not available so the issue here is whether or not to clean them up and have them recoated and reuse them as well. The rods will also have to be rebuild on the large an small ends and shotpeened. The oil pump housing will be repaired and the gears stoned,polished and coated. The cam housing will be repaired (squirters), the pistons will have the rings gapped and fitted, and the piston pins fitted to polished bores. I will also have him do the valve lash since I don't have a surface grinder. Gasket sets will have to be made up special by a place in Ohio where Neil has had templates sent to in the past for other customers. Most of the seals and o-rings can be found here with outside sources. Hopefully most of the work will be done by the 28th when I am going down to Costa Mesa to pick up most of the parts accept for the rods as we will need to figure out what we are going to do. $$$$ka-ching, ka-ching$$$$$! If any of you folks have any ideas on the rod bolt, bearings ect. let me know.

[BURN-BROS]

Doc, call Henry at Supertec. He has Ti rod bolts although I do not know if they fit your application.

[sand_man]

Hey, 'doc, my 930 parts are at Neil's too (being worked on at the same time as yours)...maybe he'll screw up and send me your engine!!!! HAHAHAA!

[WERK I]

helidoc,
I know this is getting W-A-A-A-Y ahead of everything, but we hope you can make it out to the Midwest this July for the Brian Redman International Challenge at Road America, July 13th - 16th.
It would be great to see you and your masterpiece gobbling up the tarmac at Elkhart Lake.
Not to mention seeing it cruise the streets Friday night when the beasts are allowed to go from the racetrack to downtown for the concours.
Just a thought...

If I can help in any way, let me know. I live about an hour from the track.

[NigelJ]

Hi all

I'm in the UK and am having my 962 engine rebuilt right now. I have been enjoying reading this thread and hope this will be helpful.

Bearings are not a problem other than they are expensive - around £750.00 - as far as conrods are concerned over here we stopped running titanium rods because crack testing is a waste of time due to the nature of the material. Indeed in period they were simply lifed and then thown away! We now run steel rods with no problems. Carrillo or Arrow are the preferred manufacturers at around £1400 a set.

We are looking at cutting off the barrels and using liners at the moment because the supply of head/barrel units is getting tight and VERY expensive. We expect to know the details of cost,etc, in the next few weeks.

We have just had new valves manufactured in the USA at relatively OK money -I don't have the details of who and $$$ right now but will dig it out and post here.

We have a source of new cases - that is new and unrun but not cheap. The problem with the 962 motors is that they develop stress cracks around the main bearings. Even if uncracked, I am not sure that line boring is an option because of the gear driven cam arrangement. Unless different bearings are sourced the case mating faces will need machining and that will change the cam gear meshing and that is a real problem.

Taking on the rebuild of one of these motors is pretty daunting. If I can help in any way then please SHOUT!

Nigel James

London UK

[helidoc]

Thanks guys for your thoughts.

Aaron, I will give Henry a call when I get a chance.

Sand_man, be careful or your wishes could come true and be your worst nightmare. Neil might send you the bill too.

Dave, I would like to come to Elkhart Lake/Road America but will be racing the less prestigious SCCA Formula Mazda this summer. It is probably as much fun than the 962 and much less expensive. Having spent 4 years of school in Chicago I also remember the heat and humidity wasn't much fun to deal with that time of year, especially now that I have acclimated to California weather. The logistics of traveling with the car that far are also hard for me.

Nigel, thanks for the info on the rods/bearings. What was your definition of the life of the rods? Where do you get the bearings from? Neil charges about roughly $1500 per head/liner to machine and parts but I have decided to for go this process for now. Maybe next rebuild if I have the car that long.

I am still awaiting what Neil can do as far as parts. He has some "deep thoat guy" that used to work for "the company" who is going to check and see if there are any parts left hiding around in Germany. May be he will get lucky but Roger at PMNA had told me that all the 962 engine/spare parts were shipped from Germany to them here in the US. The sad thing is that I bet all the parts I need are probably sitting in some guys drawer somewhere collecting dust and he may not even know what they are for. For example, a collegue of mine collects/rebuilds 356's. He has tons of parts sitting in drawers, shelves, boxes, bins etc. They are in his garage, shop and even filling up an attic over his garage. I know and he knows he will never use most of the things he has but collects it anyway. One man's trash is another man's treasure.

[sand_man]

I have a feeling Neil will be bringing a pretty stout bill to my azz even if if your 962 engine doesn't show up on my door step!
Funny story: Neil and I were speaking on the phone and he mentioned that an Orthopedic Surgeon was planning on rebuilding a 962 engine himself...all of a sudden the light bulb went off and I said, "Oh my gawd, that's helidoc, I've been following that post on Pelican". Neil was like, "um yeah, okay, sure, whatever..." I guess when you've been around as many impressive engines as Neil, nothing astonishes you!

[RarlyL8]

I got on Pelican to check the classifieds. Stumbled onto this thread and read every word from day one. Unreal! Thanks for sharing, that was 2 hours of my life well used!