kobayashi

So on my way home from Beaverun this weekend, the engine in my 83 NA blew up. I heard tapping which I thought might be a valve. I don't think it turned out to be a valve. I ended up losing oil pressure ( 2.5 bar compared to 5 bar normally) and was able to get off to the side of the road. Had it towed home.

I checked timing and everything is OK. Pulled the oil plug and I have a bunch of metal sticking to the magnet. So I am thinking rod bearings. Does that sound right?

Now here is my situation. I bought the 83 NA for cheap. It has a good body from Cali with bad paint. I have recently put a new clutch it in, upgraded to Wilwood brakes, upgraded sway bars, new KYB suspension. I probably have $5000 into it with taxes, inspection, tires, alignment and all that stuff. The goal for the NA was to be a spec or GTS 1 racer. I also have a supercharged 86 that is pretty much stock other than the engine. No plans for the supercharged car as of yet. What should I do?

1) Replace the rod bearings and other stuff with engine in.
2) Drop the engine for a semi-complete rebuild.
3) Take the stuff I want off of the '83 for the supercharged car then sell it for pocket change.
4) Take the Wilwoods, sway bars, seats, and other stuff off the NA (easy stuff), sell it and buy a car that has a NASA/SCCA logbook.
5) Other suggestions


Thanks for the suggestions in advance.

Grandpa#3

You have 5K in the car now. Drop the engine and inspect the insides to find out what it needs. Up in your area you should be able to pick up a long or short block cheap if needed. With any luck all you may need is rod bearings, but you won't know until you pull the oil pan. Any way you go I wish you the best of luck.

Cheers,
Larry

odurandina

strip the car and get another -- or build the car big and really screw it royal.

joonas

Take the engine apart and see what is going on. You have nothing to lose now.

tblofsky

take the engine out and do a semi rebuild. its a good idea to clean the inside so you dont send metal shavings through the new bearings.

Rogue_Ant

If you've spun a bearing - then I would not bother with that engine. Get a used block, new bearings / light rebuild and go.

JohnKoaWood

+1.. and ante up for some euro spec pistons..... up the compression, get more ponies!

OR find an 87-88 N/A motor to swap into the lighter chassis! Higher HP, lighter car!

V2Rocket

pull it apart and see whats wrong, i have a spare engine all apart if you need any parts

Oddjob

Well, if you are serious about wanting to have a 944 race car - you cant throw in the towel when you spin a rod bearing. It does happen.

If you are capable and willing to do the work yourself, just drop the motor and open it up to see what you have.

Depending on mileage and condition, the motor may or may not be worth rebuilding. But chances are, if the rod was knocking, there will be some galling on the crank journal. So the crank will likely need to be ground which then requires expensive +1 oversized bearings. So at that point, you may want to consider finding another good used short block or just a good crank to put it; that decision will depend on the condition of the rest of the motor. If the bores are in good shape and the motor had relatively low miles, probably worth rebuilding that one. If the motor is high mileage and the bores are hour glassed and scored, find another shortblock. Put in new rod bearings and install in the car.

kobayashi

The motor has about 150,000 miles on it, so it is probably not worth a rebuild. I can try to find a used motor, do a little freshening and then drop it in. The thing about the car is that it is not set up for racing at all. I have a roll cage that can be put in, so I'm a step ahead there. I would have to reindex the torsion bars, which I'm not exactly psyched about doing. Upgrade all the suspension. I would then have to get all the small things to put into the car. It just seems like it would be a really big project from here on out to make it a spec racer. If the car was already a racer, I would not mind putting in the time to rebuild the engine.

In my area it would be the NASA GTS series. Just getting into racing, how much of a difference would there be between GTS 1 & 2? I could get my supercharged car up and running for GTS 2.

Spencer - Thanks for the offer on the parts!

Thanks for all the suggestions.

JohnKoaWood

WTF am I thinking spending the $$ to have my 210K motor profesionally rebuilt..

Honestly, these motors are timeless.. mileage is NOT a disqualifier for a rebuild, in all reality, the disqualifiers are in no specific order:

Cracked Cylinder wall
Cracked block
Damaged block material

A spun bearing is a common occurrence, and at the MOST might require machine work to the crank, or replacement of a connecting rod...

IMHO what makes it not worth rebuilding is it is an early N/A motor....

Just looked it up... "Cars may be updated and backdated with parts from the Porsche 944 and 924S from model years 1983-1988 with 2.5-liter eight-valve engines only."

NO 89 2.7.. but you can swap to an 87 or 88 motor, but the internals MUST remain US factory or OEM replacement parts...

Go find a motor from an 87 or 88 and have a ball!

M758

My back in November 2002 I blew up my 47k 924S motor that I had put in my 84 944 track/race car. I blew it up so bad it broke the #2 piston when the rod journal siezed.

I then took my 147k mile 84 block that had severe coolant mixing and rebuilt that. I maintained the bores and the piston rings. I just put in new bearings for the crank and rods. I used the 87 924S heat from the motor that blew up since it was fine. I had it checked, cleaned and flattened.

I rebuilt the motor at home and ran 80 races on it. I probalbly had 30 wins and bunch of track records. 3 1/2 Years later I changed when I got my hands on 88 motor. I ran that for 3-4 events and spun a bearing. However no major carnage this time. So I stuck the 84 motor back in and ran that for another 18 months with fresh rod bearings. I pulled in about 18 months ago when it was getting soft. I had 10% leak down in two cylinders which was a result of carbon build up on one intake and one exhaust valve. I put the 88 motor back in after I rebult that one. This time with fresh rings and used crank I got for $80. That spun bearing damaged the crank, but the rest of the motor was fine.

Point is 150k on the motor? So what. My race motor that I ran 80 races had 147k before I started racing it. Not it is down only needing a head refresh. Then it will be back in once I need to change out my current motor.

If you do plan to race you need to realize motors can pop. Best bet is to get a replacement and either rebuild that and put it in or tear this one down and replace what is damaged. Ideally you always have two motors. One working in the car and the other undergoing a rebuild. That way you can minimize and down time during the racing season. Heck at nationals last year for 944-spec we did an engine change the night before the championship race for one guy that blew up a qualfying race the afternoon.


BTW... there is nothing wrong with running an 83 motor or 84 motor. Only the 88 motor has 10.2:1 pistons. These are nice and in theory make more power, but in practice never seem to make any difference. I have both and I don't mind which I run.

87 motors interally are no different than 83 motors in terms of hp.