What Questions should I ask a prospective seller before purchasing an engine?

thinkfloyd14 · 10-15-2018, 10:43 PM

I am in the market for an engine to be swapped in my 76 911. I have an engine that needs a substantial rebuild and after speaking with many mechanics, I believe it would be more cost effective to buy a rebuilt motor and either sell mine or offer as a core.

So before I go about negotiating with prospective sellers online, what are some common questions you would all recommend me asking before purchasing an engine?

Thank you!

edit: Also please note I am mechanically challenged.

T77911S · 10-16-2018, 02:47 AM

mileage
leakdown
compression done before removed or can it be done
been rebuilt
how much

Dpmulvan · 10-16-2018, 04:07 AM

Quote:

Originally Posted by thinkfloyd14

I am in the market for an engine to be swapped in my 76 911. I have an engine that needs a substantial rebuild and after speaking with many mechanics, I believe it would be more cost effective to buy a rebuilt motor and either sell mine or offer as a core.

So before I go about negotiating with prospective sellers online, what are some common questions you would all recommend me asking before purchasing an engine?

Thank you!

edit: Also please note I am mechanically challenged.

How much of a budget do you have?? Be careful buying motors online, if your not mechanically inclined I hope your wealthy. What about your fuel system? Are you running CIS ??? is the motor in the 76 stock?? Original?? Are you looking for a 2.7 or 3.0 or 3.2 ???? CIS system are not plug and play interchangeable.

dobryan · 10-16-2018, 04:25 AM

And be careful out there. There are engines that have been rebuilt by folks like this...

Att all people hurt by MotorMeister

SalParadise · 10-16-2018, 07:15 AM

It's going to seriously take a lot of time, money and energy to find a correctly built 2.7 or 3.0 on Pelican or anywhere for sale. I have looked for a 2.7 for awhile, but ended up biting the bullet (or piston or whatever) and I'm going through what I have. I figure in the long run it's going to be less money because at the end I will know what I have.

You'd have to ask for compression, leakdown, are the P/Cs Alusil or Nikasil (Mahle made Alusil too). Was the block time-serted or case savers used? Are there steel studs in there? Are there Carrera tensioners? When were the heads done? Is the oil pump upgraded or not?

And does it have any papers? And if it does, did someone reputable build it??

It's a crapshoot. If someone reached out to me on here and had a 2.7 that was done, and they were trustworthy, I would probably buy it. Every engine I looked at had some issue and no paperwork, which leaves you to rebuilding your own. Too many unanswered questions will always lurk.

Better to send out what you have to someone reputable who will do it. It will cost money, but it will save money in the end.

gomezoneill · gomezoneill's Garage

DONT DO IT. Ask me how I know. It's good to keep the original motor in the car. Rebuild what you have.

Discseven · Discseven's Garage

Quote:

Originally Posted by thinkfloyd14

edit: Also please note I am mechanically challenged.

Thinkf... not to pizz on engine buying parade but as Dp mentioned, unless the universe aligns this engine buy for you with great luv for you... it could be your engine schooling at no small cost. Think way to go is to find and deal with only Porsche guys with a solid reputation.

I can recommend Porsche specialist in Miami to talk to. George. 305-588-0874. I think he has a few engines to choose from---not sure. Top notch guy. Mechanical genius.

If you have matching numbers car, might think about keeping it that way. Or at least saving your old engine for downstream. I did a swap like you're thinking of and while the engine I got is great, I regret not being smart enough at the time to save the old engine.

Good move to inquire about this. You're off to a fine start IMHO.

Pcarmiddie · 10-17-2018, 07:39 PM

And what about people that don't even have an old engine?

Trackrash · Trackrash's Garage

Lots of good advice. Realistically any motor you buy should be considered a core, unless you can see it running.

Too many "yea it was owned and rebuilt by an experienced German mechanic....".

I would want to see a build sheet to document any previous work done.

I recently sold a motor. I had videos of it running, the buyer did a leakdown in my garage, and I had the ORIGINAL BUILD SHEET from 20 years ago. In addition I had a DYNO sheet. Plus the buyer knows where I live....

It took me something like 3 years to find the motor I have now. There was no history, but it was a COMPLETE '78 SC motor. It had everything from the air cleaner to the muffler with a back dated exhaust AND it had the CDI! I looked under with a mirror saw that it had MAHLE cylinders and reached for my wallet.

With no history, I did a COMPLETE rebuild. I did find some internal problems like broken head studs and a collapsed tensioner.

thinkfloyd14 · 10-17-2018, 08:04 PM

Thanks to all the replies. I have taken all of your advice for consideration. My car currently does not have a matching numbers engine, so in that respect it would not matter to me.

I have found a 2.8 (2.7 bored out to 2.8) liter engine fully rebuilt from an engine builder in Scottsdale, brand new, not even fired up. I am still negotiating with him at the moment and have asked all the above in the process.

This forum is a great resource. Thanks to all.

DRACO A5OG · DRACO A5OG's Garage

Get a detailed list of all parts he claims to have put in. Just in case a tear down is needed.

Break a Leg Brother DTLA.

Too bad you still have to smog her :-(

3rd_gear_Ted · 10-18-2018, 10:46 AM

From 10,000 ft;
The bottom ends can last a long time is one assumption.
You will have less problems going forward if you assume the need for a top end rebuild.
If this is stated before engine purchase and seller knows immediate partial disassembly is occurring, sometimes stories change or there happy to show their work.

Coastr · 10-18-2018, 01:14 PM

Don’t ask questions, ask for documentary evidence.

I once bought a ‘newly rebuitl’ Engine with a pile of receipts. It lasted about 1000 miles. At 700 miles it started to sieze up when stopped and hot - couldn’t start unless pushed or cooled down. Either the receipts were fake or the builder didn’t know the first thing.

If you found a shop selling one then great. If you find someone selling a good motor the obvious question is ‘why?’

Matt Monson · 10-18-2018, 01:47 PM

Quote:

Originally Posted by thinkfloyd14

Thanks to all the replies. I have taken all of your advice for consideration. My car currently does not have a matching numbers engine, so in that respect it would not matter to me.

I have found a 2.8 (2.7 bored out to 2.8) liter engine fully rebuilt from an engine builder in Scottsdale, brand new, not even fired up. I am still negotiating with him at the moment and have asked all the above in the process.

This forum is a great resource. Thanks to all.

Make him fire it up and run it in for you. I would never buy a brand new rebuilt engine without it, or a 30 day iron clad money back guarantee.

Trackrash · Trackrash's Garage

In addition to all the above. Get detailed descriptions of all the parts that were replaced or re-used. Also you would want to have all the machine work documented and what shop that performed it.

Also what is the compression ratio? What cams?

Does it have carburetors or fuel injection? Exhaust?

Get a copy of the build sheet and post it here

with

a picture of the motor and you will get a lot of experienced advice.