DIY engine rebuilds -- any regrets long-term?

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johnsopa
Posts: 17
Joined: Mon Aug 31, 2020 1:17 pm

DIY engine rebuilds -- any regrets long-term?

Post by johnsopa »

Figured I'd post this here since 964 and 993 people can respond...

My '90 964 has 50k miles, runs great but leaks a bit. It was never resealed. I replaced the clutch and installed a LFW and did the valves last winter. I wanted to sell the car but my wife loves driving it but it seems a bit slow /sluggish to me compared to our other cars.

So, I was going to bite the bullet and have Steve Weiner do the rebuild, doing a 3.8 with ITBs. However, he retired and I will have some time this winter, so I'm thinking of doing the rebuild myself.

I would have to send things out for machining (machine the heads for a gasket, clean up the heads, maybe do bore-in 3.8 P&Cs), but feel comfortable doing all the prep and assembly myself. I already bought the engine stand yoke.

I've consulted with Steve Weiner a few times and he indicates there are some "secrets" to getting these engines rebuilt properly so they perform well and don't leak long-term.

I wanted to see if anyone here has done a DIY rebuild or knows anyone who's done it. Any regrets long-term? Any truth to the "secrets" that aren't readily accessible to DIYers?
Current:
'18 991.2 GT3 MT -- '16 981 GT4 -- '16 981 Spyder -- '90 964 C2
Radical SR4

Prior:
SRF Gen2 (x2)
'09 987.2 Cayman S -- '98 993 C2S -- '92 964 US Cup Car #44 (I should never have sold this car -- it could've paid my son's college tuition!)
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sundog
Posts: 393
Joined: Thu Jul 30, 2020 7:59 pm
Location: Livermore

Re: DIY engine rebuilds -- any regrets long-term?

Post by sundog »

johnsopa wrote: Mon Sep 21, 2020 7:42 pm Figured I'd post this here since 964 and 993 people can respond...

My '90 964 has 50k miles, runs great but leaks a bit. It was never resealed. I replaced the clutch and installed a LFW and did the valves last winter. I wanted to sell the car but my wife loves driving it but it seems a bit slow /sluggish to me compared to our other cars.

So, I was going to bite the bullet and have Steve Weiner do the rebuild, doing a 3.8 with ITBs. However, he retired and I will have some time this winter, so I'm thinking of doing the rebuild myself.

I would have to send things out for machining (machine the heads for a gasket, clean up the heads, maybe do bore-in 3.8 P&Cs), but feel comfortable doing all the prep and assembly myself. I already bought the engine stand yoke.

I've consulted with Steve Weiner a few times and he indicates there are some "secrets" to getting these engines rebuilt properly so they perform well and don't leak long-term.

I wanted to see if anyone here has done a DIY rebuild or knows anyone who's done it. Any regrets long-term? Any truth to the "secrets" that aren't readily accessible to DIYers?
Sorry, but I just saw this one.

I rebuilt mine by myself. I certainly wouldn't do it just for leaks, as unless you get an A+ it will leak.

I took the 3 day engine rebuild class at Jerry Woods place here in the SF Bay Area. It is quite a task, and requires a lot of different tools and sealants to get the rebuild correct. I have a couple of leaks, but they are at the valve covers, and maybe one small one in the case. I put a GT-3 oil pump in mine, so the pressure is higher than standard.

The process took me a long time, but I did enjoy it very much as a learning experience.

I did the rebuild at about 120,000 miles. Since then I've put another 65K miles, with a large portion of those on the track. The engine holds up great, just leaves a mark. So I got a B on the rebuild.
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Ponchobroke
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Re: DIY engine rebuilds -- any regrets long-term?

Post by Ponchobroke »

John,
Did you ever do this?
I did a top end w/Steve and it turned out terrific. However, when it came time to do the entire engine for its 2nd life @ 165,000 it send it to Jeff @ Rothsport and have never been happier. The engine is new and includes the RS upgrades done during the top end.
John
Pic's - '95 C2 Polar Silver - 168k miles Rebuilt w/RS Intake and RS Cams (by Rothsport) & LWF, PSS 9's/Turbo Sways(Carnewal), Strut Bar, FDM SSK/Golden Rod, Tie Rod Pin, RS Engine Mounts, F1 Trans Bushing
Pic's - '66 912 Ivory - 141k miles
'03 C4 Cab, White - 227k miles
’18 Macan - Atlas Gray Metallic, Bone Stock - so far
'17 Denali 2500 HD
All Built & Maintained @ Poncho's Garage
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3.2 Targa
Posts: 209
Joined: Wed Jul 29, 2020 12:02 pm

Re: DIY engine rebuilds -- any regrets long-term?

Post by 3.2 Targa »

A pitted cam precipitated the top-end teardown of my 3.2L. It has 85k miles on it.
The cams are at John Dougherty's and the heads are at Elverud's getting rebuilt.

I'm fortunate to have some resources here locally. A 40-yr dealer tech and some others that have gone before me. I've found Pelican to be a great resource.

For me, this was about learning and doing. I've checked all the Px&Cs and they are all well within spec. By my calculation, the engine is about 45% done in the Ps &Cs. From what I can see/feel of the bottom end, it is solid.

I'm doing the exhaust-side head studs and updating the rocker shafts and a few other things.

Proper surfacing of the mating surfaces without changing tolerances is the trick to a leak-free build. It is some art and science.
Scott C.
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milrad
Posts: 298
Joined: Wed Jul 29, 2020 12:58 pm
Location: Fort Worth TX

Re: DIY engine rebuilds -- any regrets long-term?

Post by milrad »

I had my 993 rebuilt at 50k because it was leaking. I hate leaks. So yes, I’m a tormented Porsche owner lol. I had Pat Williams in Memphis do it. Not cheap, but no leaks 5 years later.

In the other hand, I’m in the reassembly phase of mostly rebuilding my 928 engine. Different animal for sure. I’ll let you know in a month or two if I regret it!
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