924Board.org

[ideola]

It's been a LONG time since I've had the free time to pursue anything Porsche related...including visiting the board. Sorry for the absence.

Here's something I would LOVE to get feedback from those of you experienced with engine rebuilding.

We FINALLY got the motor pulled from the '80 931 wide body last week, and I'm working on my rebuild plans. My question is, how much replacement is too much??? I went thru every single diagram in the parts catalog for the 931 motor and identified every part that looked like it might should be replaced (see complete spreadsheet for detailed analysis). Then I did some basic checking on parts cost at Pelican to baseline what my projected costs would be. Here's what I came up with:

Bottom End Rebuild: $659.72 (includes both motor mounts)
Top End Rebuild: $907.34 (includes injectors and raceware headbolts)
Cooling System Refurb: $411.32 (new everything but radiator)
Clutch System: $1,192.03

What's scary is that these numbers don't include the rod bearings, the set of seals for the block, the set of seals for the head (all of which I already have). Nor do they include other necessities like the wastegate rebuild, the turbo rebuild, decking the block, grinding the valves, or any of the other misc hardware items, like studs and nuts.

Other things I didn't include but I'm wondering about:
new crank gear? add $60.24
new cam gear? add $27.75
new oil pump? add $414.09
new valve springs? add $90.16
new piston pins? add $149.52
new half shafts? add $487.40

To put it another way, what things am I going to regret NOT replacing? Are any of these items on the "must replace list"? Also, if anyone bothers to go to the trouble of looking at the spreadsheet, what am I missing that should be on the list???

Thanks in advance. Good to be back
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erstwhile owner of just about every 924 variant ever made

[Paul]

Before you go any further call ebsracing, these guys are great and will answer all your questions, plus their prices are usually pretty good.

http://www.ebsracing.com/

Again call them, don't bother even trying the website.
_________________
White 87 924S "Ghost"
Silver 98 986 3.6l 320 HP "Frank N Stein"
White 01 986 "Christine"
Polar Silver 02 996TT. "Turbo"
Owned and repaired 924s since 1977
Porsche: It's not driving, it's therapy.

[jpab924]

the guy you want to talk to at ebs is Don....and I feel that you are going overboard.

And if you have to go overbore, don`t forget the price tag on the pistons and rings you`ll have to buy. Don`t forget to add machine shop costs into the budget.

Dan, we need to settle unfinshed business.

JP

[ideola]

JP, just sent you a PM.
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erstwhile owner of just about every 924 variant ever made

[924RACR]

Yeah, go to EBS. Period.
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

[emoore924]

If it helps, I just had a top-end done and including labor and machining, it cost about $1k. It included porting work on the head, same valves, 3-angle valve job, new guides with a little turndown on the guides, and a tweak here and there. Top end turbo gasket set. Various and sundry "tidying up" efforts under the hood (rerouting hoses, tying things down...) and all the labor to take it apart, mess with it and put it back together.

Nothing was done below the top deck on the block.

[J1NX3D]

[J1NX3D]

[My924gtc]

When it comes to the engine and the need for rebuild advice and supplies, yes EBS is the best.

Friendly, knowledgable, and their pricing is pretty fair, though not the rock bottom out there. Experience comes at a price, but most of the time it is money well spent.
_________________
MJ
'81 924 2.0L T
'82 924 2.3L SC/EFI <---online fall '06

Sponsor of the 944 Cup and Super Cup
Sponsor of the "2006 Battle in the Badlands"

[924RACR]

Yes. I use Paragon all the time, more for suspension stuff, ubt not universally. But when it's time for serious engine/transmission work, etc., I'll often turn to EBS.
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

[Kenodog]

It's funny but when I listed all the work i'd done to my car you said I paid WAY too much.In fact you said I could do the engine re-build PLUS a rebuilt turbo for $1500.

Change your mind on that original quote ?
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1979 Euro 931, Olive
1981 931, Sabine
1991 Ford Ranger XLT 4x4, Ricky
1996 Ford E-350 ex-FedEx Van
2014 Mazda CX-5 (Kinderwagon)
2019 KTM 790 Adventure
2024 KLX300
2024 KLX140

[ideola]

No haven't changed my mind at all. And to be clear, what I said was that doing a stock rebuild could be done for $1500, which I still firmly believe. The point of that comment was that for 1/10th of the $20K you spent, someone could rebuild to stock specs, have decent performance numbers, with a bunch of cash left over for other stuff. With some of the great deals I've found on NOS parts, I'd easily be able to do a stock rebuild for <$1500.

However, relative to THIS particular post, I'm NOT doing a stock rebuild on this motor. It will be much much more than stock, but I guarantee you I won't spend $20K, and I fully expect to exceed 300 HP. I also am not looking to recoup my "investment"...it's a hobby, so it won't bother me to spend the dough, because my intent is to drive the hell out of the car when I'm done with it, rather than try to turn around and sell it.

The budget on the wide body is hovering somewhere between $12K-$13K right now, and that includes custom wheels, fat rubber, full paint and graphics, as well as all of the performance mods...in other words, a completely finished project. The nice thing about living in the motor city capitol of the world is that I can get custom bits and work for much less than the usual porsche specialists. These folks know what they're doing, and there's lots of competition, so if you shop around and source individual portions of the work to specific jobbers, you can get quite a bit more for your money.

Also, btw, on a related note, I sat down and figured out that I have purchased and titled six water-cooled Porsches in the last 18 months, and spent a grand total of exactly $9,900.00 ... just one example of what can be done with less than $20K. Only one of those was a rolling chassis. Three of remaining five are currently on the road, the 928 is garaged for the winter, and the wide body is undergoing complete reconstruction.

In terms of getting them all on the road, here's a breakdown:
1981 NA : spent about $3K for all mechanical and cosmetic improvements
1981 WSE: sold it; nephew has spent about $300 to make it road worthy
1980 931 WB: spent about $1000 so far for various bits; budget of ~$12K to finish as a streetable race car (top priority)
1980 931: budgeting about $1000 for minor mechanicals and cosmetics over the next year
1980 928: spent about $4K on hybrid motor bits, need another $6K to finish that project (back burner right now)
1980 931 rolling chassis: will be chassis swapped with the WB during the race car build; extra bits will be parted to provide add'l project funding
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erstwhile owner of just about every 924 variant ever made

[Dans931]

I have an 80 931 motor that I rebuilt a few years ago, but only used briefly before the car got destroyed in a crash. I bought an 82 931 but didn't need the motor. I sprayed inside with fogging oil, so it should still be good. It is complete with the bell housing and new clutch attached. I should still have all the receipts. Some performance work was also done.
let me know if interested. Either way, the advice on here is good and always free.
Daniel