Rebuilding a 962 motor

[jdm61]

Originally posted by Carrera3.5L
Helidoc,

As you heard from one of your other sources, the heads/cylinders can and do crack at the bottom where the weld joins the two, causing an obvious water leak, but I'm not sure how accurate the 100 hour figure is. A typical 962C engine rebuild was at 25-30 hours during the GTP days and although cracks weren't usually seen at these hours, the parts were always zyglo'd to make sure. I would make sure that you do this process (I'm sure you already know this but others reading may not be aware) if you plan on retaining the heads/cylinders and not discarding them in favor of new Porsche units or Neil's creation. In fact, it is probably prudent for new units as well just for insurance.

Also, there were a few different camshaft profiles available for these 4-valve, 4-cam motors. Camshafts for the endurance races such as Daytona, Sebring, LeMans, etc were generally changed for fuel economy (along with the boost being lowered) and different profiles installed for the "sprint races". The cam profiles and boost levels were essentially the only difference between an endurance motor and a motor prepared for a 3 hour race. Eric at PMNA can probably still get you the profile you need/want (depending on what you have inside now and if you wish to change) and its possible that Neil at Performance Developments might have some of his own profiles as well.

If you are interested in checking the cams to see what you have, send them to me and I would be happy to put them on the cam doctor for you.

I'm not sure that Dieter at Andial would have your engine information, as he was running the road side and the 962C motors were all built on the race side under the direction of Alwin Springer. I guess it is possible that the records were transferred to Dieter/Arnold when Andial's race side was morphed into Porsche Motorsport but I would think that PMNA would have the records. I may be able to help you there if you encounter some difficulty in obtaining them.

Ralph

youjust answered my question. I was wondering if this would be one of the engines where they electron beam welded he heads to the cylinders. When people buildnew 962 type ngines, do they use the original type block or the newer GT1/GT3 one?

[helidoc]

Ralph

I have been off line for awhile but thanks for letting me see what's happening to my "baby"! It's a little lonely here in its' garage space but I will be filling it next week with what as my friends say is a German donorcycle (one of those on the rebound things since all the race cars will be gone by November). I would have loved to keep things going but atleast you are providing some insight in areas I wouldn't have been able to. I would have liked to see the timing process. I'm not quite sure why Neil felt it was proprietary but he never has returned my email since he got the check, so I never got that far (maybe that is why my car was purchased so quickly...a conspiracy to keep me from posting the secret details of the inner workings of this motor.....ha, ha, ha?!!). Keep up the good work. Oh, and one last photo of the sad departure as the car limped off without its hind quarters...

[Carrera3.5L]

VZ,

I'm sorry, but I don't have any photographs of yours/Akin's car, that was before my time... Most of my pics were of the engines in various states of assembly, but I have a few Dyson/Bayside/Busby/Brun/Joest images from mid'88 to '93 who were about the only teams left running cars at the end of the GTP era...

Congrats on the old 962 air-cooled car still having the fastest mph and total miles run for the 12 Hours, but we both know that luck plays a major part in that, right? The number of caution periods and how long those caution periods are for usually determine that statistic. Still, it is surprising that it hasn't been broken for 20 years by the much quicker cars of today...

JDM,

That is actually a very good question and from what I know the answer is no. I don't believe people are building "new" 962C engines (simply because of parts scarcity) but if one wanted to would probably start with the 930 case since 962 cases are few and far between. The GT1 motor could be considered the next step or an evolution of the 956/962C motor I guess, but its parts are different and from what I know not interchangeable. A major difference right off of the top of my head (and there are undoubtedly more but I've only seen (1) GT1 motor apart and it was a few years ago) is the 956/962C had individual heads/cylinders that were electron beam welded together while the GT1 motor had (2) 1-piece heads for each bank and the heads/cylinders were not electron beam welded, but rather had a gasket between the two. This arrangement is similar to the 959 engine rather than the 956/962C. Also, the 962C had gear driven camshafts, while the GT1 went back to chain driven cams like a conventional 911 motor (also the 959). I would venture to say that the GT1 motor shares more lineage with the 959 than it does with the 956/962C.

Heli,

Neil's taking great care of your baby, hopefully can get it onto the dyno next week for the new owner and run it in. Neil mentioned that the guy is in somewhat of a hurry, but it looks like he has some chassis prep work ahead of him as well!

I found an old pic of what I believe is your car (chassis 146) at the 1992 24 Hours. Car number was #52 with sponsorship from Team 0123 & Art Sports. Interestingly, the car was entered with a 3.0L motor while yours is definitely a 3.2L now. Drivers were Hurley Haywood, Eje Elgh, Roland Ratzenberger & Scott Brayton. Vern Schuppan was listed as a driver but DNS. The car qualified 9th on the grid (but started 11th since it was classed as a GTP car and the LM cars took priority on the grid) with a time of 1.41.900 and finished 3rd, 13 laps behind the winning Nissan R91CP LM class car. Your car was considered a long shot to win, but at least it finished! The other (2) 962C's entered that year that were contenders (from Porsche's view at least) were from Joest, and both cars failed to finish, one retiring with electrical problems and the other losing the engine...



The cam timing process isn't proprietary, just what he sets them at as he doesn't necessarily time them to the factory setting... I'm sure there are other guys reading this thread who may dabble with a 962C engine, let them do their own homework...

I'll let Neil know that you are trying to get ahold of him, he was busy/stressed with getting your old motor done as well as with the 904 motor that is sitting on the stand next to it...

If you are interested, send me a PM with your address and I'd be happy to burn you a CD with images of your motor going back together so you have it for posterity...

I'll post some more internal engine pics tonight after dinner and after my son goes to sleep...

Ralph

[Carrera3.5L]

Originally posted by VZ935
Ralph..very cool thanks for continuing on with the thread... would love to know if you have any pics of my 962... also, as far as competition... my car still holds the record for Average MPH and Distance Covered at the Sebring 12 Hour to this day , 20 years later .I believe some of the faster competition you mentioned ran that same configuration at Sebring too ..... Oh , it crossed the finish line on three wheels But you are right.. there were some brutally fast cars to come ....

VZ,

I just found some images and info on your car from someone's site on the net, don't know how accurate the info actually is. You may or may not have already seen this...

http://www.xs4all.nl/~robdebie/models/962.htm

The only race your chassis won was at Sebring, but other than the (2) 24 hour races that would be the one to win! There were alot of 962/962C's that were built that never tasted success. The March85G-Buick (Holbert had a similar car with Porsche power before the 962) in the hands of JPJ was on pole at 2:11.416 while the Akin car started 4th with a time of 2:13.843. A clean sweep that year, with Busby's 962 & Holbert's 962 finishing 2nd & 3rd. That was an accomplishment in itself as the "privateer" 962 teams had the deck stacked against them versus the "factory" Holbert team in terms of the latest engine updates and support.



Kind of a grainy image, but it's definitely your car...

Ralph

[Carrera3.5L]

Here are some more pics of engine number 253 going back together...

Crank, rods, oil pump & intermediate shaft resting in the case. Note the scavenging of the mag oil pump, gotta keep that oil out of the case!



Notice the lightweight straight cut intermediate/lay shaft gear. Definitely not quiet!



Also note that the crank hasn't been knife-edged, even though the motor can spin to 8,200 rpm...



The backside of one of the Mahle 95mm pistons:



Here's a shot of the pistons installed on one side of the motor. Note the gear drive housing is also fitted:



That's it for tonight, arguably the hardest part of reassembly is coming up...getting the cylinders/heads/water jackets onto the motor without breaking a piston ring!

Ralph

[Carrera3.5L]

I did some more "research" today regarding some of the history of Helidoc's old car, and found out that it raced at LeMans in 1990 & 1991 and at Daytona in 1992. I'm sure Helidoc knows all about this before he originally bought the car but I thought it would be interesting for the rest of us...

In 1990, the car was red with Takefuji as the primary sponsor and was #33. The motor was 3.0L in displacement. It was driven by Hurley Haywood, Wayne Taylor & Rickard Rydell. It qualified 27th with a time of 3:45.440 and finished 12th, 27 laps behind the winning Jaguar XJR-12 of John Nielsen, Price Cobb & Martin Brundle. If any of you ever had the pleasure of listening to the howling 7L V12, it gave you goosebumps, especially at night...




In 1991, the car was repainted and the number changed to 53 while the motor remained a 3.0L. It was raced under the Schuppan/Team Salamin Primagaz banner and was driven by James Weaver (one of the quickest 962 drivers there was), Hurley Haywood and Wayne Taylor. The car was only 29th quickest in qualifying with a time of 3:55.706 and started 33rd due to the class structuring. Unfortunately, it DNF'ed and was 46 laps down at the end to the winning (and surprising) rotary powered Mazda 787B of Volker Weidler, Johnny Herbert & Bertrand Gachot.




I already gave some info about the 1992 24 Hours of Daytona previously. Here's the same pic as before:




Geez, I hope that I'm talking about the right car...

Ralph

[Carrera3.5L]

Here are some more pics of the engine going together...

One bank of cylinders/heads in their water jackets but without the inlet & outlet water pipes installed:




One bank installed (looking at the intake side) along with one of the cam housings:




Side view before the cams are installed:




View from the exhaust side:




Straight on view into the cam housing:




One more side shot with the oil filter housing (easy to change the filter right now, eh?):




On to the next post...

Ralph

[Carrera3.5L]

Here's a few more...

One pair of intake & exhaust cams installed in a cam housing. Notice the straight cut idler gears meshing with an intermediate gear. No chains in this motor and the gears make it sound like an out of tune sewing machine imo...



Just another note to mention, the valve shims that are available range in thickness from 1.50mm all the way to 3.20mm.


Oops! I've gotten this all backwards (I'm just posting Neil's images consecutively, I guess I should have planned a little better), here is the assembly on the bench before going on the motor:




Heads with valves & springs installed (looking from the exhaust side), just waiting for the cam housings...



Side view (before the gear housings are installed):



Also notice that the hole where the 930 distributor would normally reside is now capped off...


Here's a view from the intake side of the motor of the heads with the valves/springs ready to go:




Side view of the same:




One more post with the last of the pics I have at present...

Ralph

[Carrera3.5L]

Okay, the last of them for now...

Another pic of a cam housing on the bench with a pair of cams...



Alot of M8 nuts and washers on this engine, eh? Also notice the red, rubber mallet in the background? A race engine builder's best friend, if something doesn't fit, simply beat the hell out of it until it does...I'm just kidding


Cam housing looks a bit naked without the rest of the valvetrain, doesn't it?




Close-up view of a pair of cams with idler gears installed and just barely making out one of the intermediate gears that helps make it all work...




One last view from the underside peering into the exhaust ports:




Looking down from where a gear housing will soon reside with a glimpse of the intermediate shaft and an oil scavenge.




That's it for now everyone, hopefully I'll have a few more in the coming days along with some video and sound clips on the dyno at some point...

Just to warn those of you who haven't heard a C motor before, they are a real let down. They sound real dull and blah and one would never know they are a race engine making gobs of power. The sound clips will be anticlimatic for many...

Ralph

[Mr9146]

Dude...

Sweet...

[911 tweaks]

nice work Dr. Ralph!! You are an expert story teller and photographer...keep-er goin'

[sand_man]

Man those cam boxes are quite extraordinary!

[}{arlequin]

jeepers... how did i miss this thread in the first place? awesome. can't wait to sit at home and do some reading

[CBRacerX]

Thanks Ralph!!!!!

[Cupcar]

It is amazing how similar this engine is to the GT2/3/Turbo engine in the latest 911 cars.

Siamese the 3 cylinder heads per side to a single piece, change the cam drive to chains, change the oil pump and you pretty much have it don't you?

[sand_man]

I can't wait for the dyno footage!

[efhughes3]

After having been out of the country for a couple of weeks, I'm catching up on the progress. Nice job Ralph! It's almost like you've done this motor build documentation thing before...

[Carrera3.5L]

Just a little update and sorry to get all of your hopes up (as in putting this thread back to the top so there must be some new info) but still waiting for the wiring harness from the car to arrive so can dyno...

Attempts to get a harness and/or dyno at PMNA were rebuffed...

It should be arriving shortly, but you'll just have to sit tight for a while longer...

Ralph

[Cupcar]

If PMNA won't play, how about taking it to Jerry Wood's shop for a dyno run?

[Carrera3.5L]

Originally posted by Cupcar
If PMNA won't play, how about taking it to Jerry Wood's shop for a dyno run?

There is an engine dyno here locally, no need to truck the motor all the way up north...

The only reason why PMNA was in the mix is because they already have everything set-up for the Motronic 1.7 management. It would have been quick and easy...

Rebuffed probably isn't the correct term, the money quoted was absurd (even by 962 standards) which basically says not interested unless we pillage...

The harness will get here in due course and the project finished up...

Ralph