3.0 Engine Advice
 

I think this is the right forum to ask this question:
I have been looking for some time now for an engine for my '83 SC coupe project car. I have found several engines, all of which have turned out to have major shortcomings/issues.
I just found a 1983 3.0 cabrio engine that seems may be closer to a "minor issues" engine. Seller says he has no idea what mileage is on it but it is currently transplanted and running in an '81 coupe....says I could drive/hear it run.
He says leakdown is 5 to 10% (cold). Does not have Carerra tensioner update (re no oil lines to covers) but has turbo valve covers. Has new one piece oil return tubes, new cam housing gaskets. Seller says "looks like it had recent rebuild/refresh." It seems to be a turbo cased '83 by looks of case drain plug location. I may go look at it tomorrow (several hour drive each way) but would like to see what you guys think before doing so. I have several pictures which I can post if necessary.

Thanx,

1. How much is he asking?
2. What are you prepared/planning to do to it prior to installation?
3. How much do you drive and how long do you expect it to last?
4. Can you contact his wrench?

1. $4K
2. I feel comfortable doing minor top end work if needed but would rather be able to install into car "as is"
3. I own 2 pcars and this one will be a streetable DE/track car. If I can get 20 to 30K miles out of it I would be happy.
4. He is a used parts operation, this car is one he recently acquired. He does know the history of it, as he sold the engine to the original owner as a transplant engine 5 years ago...don't know if I can find out who the wrench is.

I think the price and your expectations are in line.

Thanks for your 2 pennies worth PBH.
Also, does anyone know whether there are any differences between a cabriolet 3.0 and coupe 3.0? I heard that the engine mounting bracket is different in some way.

Price sounds ok with those numbers cold although I would like to know both the compression and leakdown with the engine warm. Like you pointed out I think you will need a different engine mounting bar.

Wouldn't cold leakdown numbers be a better indicator of health than warm? After engine warms up, wouldn't expansion create a tighter seal on all gasketed/joined areas leading to better (lower %) results?

I believe low cold numbers are not abnormal. Anyone else care to comment?

The rear engine mount bar on a cabrio has a dampner on it which allows it to have a controled twist. Most are worn out by now. I'm looking for a solid one. You should especially for racing. 81 USA = K-lambda CIS with computer. Get him to include the working one If you don't have it in your car or if your cars is a Euro. Euro 83 had no computer (Was K-basic.)
Mine is a late 83 Euro 930/10 k-basic. They also used the Carrera case because as I herd they ran our of the SC cases (Can someone confirm this.) There is no sump plate and the drain is in the case itself.
Will he let someone you know do the leak downs or will he do them while you watch? That would give you better confidence.
If you buy it have someone go over it and replace simple things before you put it in.

What's with the rest of the car? I need some body work. Post some pics when you get back! Where is it located?

William,
Per your "81 USA = K-lambda...." The engine is from an '83, not '81. The car it is currently in is an '81. Does the '83 engine have the same requirements? I have the original Jetronic box from my '83 but not the CD box....is there a specific CD unit for this engine?
I will bring a compression tester and will ask him to do a leakdown in front of me....good idea.
The rest of the car is an '81 coupe. Let me know what you are looking for and I will get some specific pics for you.

The 'turbo' valve covers were standard on the SC. I think William says 81 and up (81-83) are O2 sensor cars and all need the brain. A much superior setup than the air pump deal on the earlier SC.

Cheers, George

Thanks to all who replied so far.
Another question, as I am about to leave to look at engine:
There has been no Carerra update to chain tensioners.....should the price I pay include a negotiation for this item (he wants $4K)?

Chain tensioner upgrade is a necessity and part alone will be $450, I'd say $150-200 to install. The engine mount bracket is an easy change and can be found used for $50. Price sounds good. My only concern is the "looks like it had a rebuild/refresh." That could be anything from a top end job to a cleaning. I wouldn't bank on much. Good luck.

John

If you are on a budget and still want to be safe, you can check your non oil fed tensioners every 40k miles and installt the $29.99 anti-collapse collars.

The main reason for chain tensioner failures is the narrow idler arm setup that was changed to the wide setup in 1980, IIRC. The oil fed tensioners were only the icing on the cake to get things perfect. And those fail too, just not as likely. To keep the oil fed jobs from collapsing, racers install travel limiting shims (to keep the tensioner shaft from bottoming out) in the body of the tensioner that have the same effect than the earlier 'crash collar'.

George

Well, I just returned from a 12 hour expedition and I caved....I bought the engine.
I did a compression test on it and leakdown as well. Engine was in car and started pretty easily with no visible smoke. I ran it for approx 20 minutes and it idled very roughly...only to look down and see distrubutor moving...his mechanic did not tighten down nuts on dist housing when they were getting it to start yesterday.
Numbers on engine looked like this:
Cylinder# Compression Leakdown
1. 164 7
2. 169 9
3. 170 10
4. 175 11
5. 174 19
6. 165 9

There was what seemed to be a noisy valve on the right side of engine as it ran.....I'm hoping this is simply a mis-adjusted valve and/or timing issue.
There was no visible oil leakage from anywhere and engine looked fairly clean all around. It looks like someone cracked (opened) the case as I could see liquid gasket material (whitish) that looked somewhat new. Same with the timing chain housings and other engine seal areas.....only gasket material here is red in color. I'm hoping that whatever work was done on this thing was done satisfactorily. But as John's Workshop once stated, "there all a pig in a poke until you have it spread out in front of you"
As I mentioned earlier in this thread, engine does not have Carerra tensioner update.....but after asking for a deducton off the price ($4K), seller threw in a new Carerra tensioner kit (with the exception of new gaskets and the covers, which will be used and he will be shipping to me when he pulls them). He also gave me fuel accumulator, filter and fittings, charcoal filter, cruise control servo, brainbox and harness but would not budge on also throwing in the Bosch CD unit, which I had to purchase seperately (but I think I got a good deal on it). He did give me a 90-day "no knock" warranty on the engine, so I have to get moving on whatever upgrades I need to do and get it in the car and running for a while prior to the expiration of this.
A few things I think I need to do to it immediately and could use some advice:
1. Tensioner update.....I have both of Wayne's books and he makes it look simple in "101 Projects..." Is it really this simple and should I try it myself (I know the catastrophic nature of an incorrect procedure)?
2. Valve job....What do you guys think of a newbie attempting this?
3. Clutch bearing seems like it has a lot of play (he left flywheel and clutch on it for me). This doesn't look terribly difficult either...right or wrong?

These are the immediate items that I can see need to be addressed. I would love to hear other suggestions as I'm sure there are more things that might not be a bad idea to do before mounting engine in car.

(I am very mechanically inclined but certainly don't claim to be a Porsche engine expert at this juncture in time).

I am new to Pelican here and from my recent threads and the excellent feedback and knowledge I've picked up, I seriously feel like you are a bunch of great guys out there...It makes me feel a lot more confident taking on some of the chores involved in restoring a car, knowing that I have that support here.

I welcome any suggestions for my new project engine (I only have 90 days to fixen' and installin' it and makin' surein' itin' runnin' okayin').

Thanks guys.

PS. William, I got some pics of body parts from the car my engine came from (real nice shape fenders, hood and doors), as well as some other fenders.....I can hook you up; let me know if you want to see them.

Ed:

I'd slap the engine in your car pronto to get as much miles on it as possible to make sure your warranty is worth something. With those compression numbers, adjust the valves and if things look good under the vavlecovers, go! I belive if anything major is wrong with the engine, it will show within 1k miles.

The chain tensioners are easy to upgrade, you just need to make sure the chain doesn't jump while there is no tensioner tensioning it. :) A wire, clamp or ziptie will ensure it stays under tension. Also, checking the cam timing after install will be cheap insurance and good practise anyway since you have an unknown engnine on a stand that is nicely accessble!

Congrats on the purchase. Sounds like you have a very good chance to have a recently redone engine that will give you many troublefree miles.

G

ED, At this point, I agree with aigel. The chain tensioner update is easy at this point. If your careful you won't get into retiming the cams but it would be good to check them and re-time if out of spec. It's a lot easier if out of the car. I'd check out the wear on the clutch disk and maybe replace it with the bearing. There is also a seal on the transmission that would be good to change. Don't forget the o-ring on the guide tube if you order this seal. Bently's book shows a makeshift tool to remove the guide tube from the trans. If you don't have the book let me know.

How long was the engine sitting?
A compression test and a leakdown test are different. I would do the leakdown before you do anything else. This is done with the engine cold and not running. If there are any major problems it should show up with the leakdown and help you diagnose the problem.
If there is a major problem you could return the engine without wasting any more of your time or negotiate a better deal. (It's probably ok but you said you didn't see it sunning smoothly.)

If the engine hasn't been run for a while It could just be bad gas causing the problems. These often will go away after running clean gas thru it with injector cleaner.

Your question: 81-83 K-lambda are the same in USA. My point was that the ROW cars have no brain.
There are a lot of options for ignition besides the original CD box. There are just as many opinions as which ones are the best. My car has the permatune unit because it was there when I bought the car. It's working fine. Aftermarket are a lot less expensive than the original.

I am intrested in the body parts so post or e-mail the pictures to me.
Where is this car. I'm in Maryland, just west of D.C. I'd just go look but it's probably several hours from here.
Thanks and good luck!

William,
What's the best clutch to put in?
Is there anything to watch out for/caveats when doing the tensioner update?
What is involved in retiming the cams and how necessary is this?
Which seal on the transmission are you talking about? I do have the SC Bentley book so maybe you can refer to a page number.

Owner says engine was sitting for 5 years. I did do both a compression and leakdown test (see results in post above) on warm engine.

I did buy a used CD unit with car (Bosch original).

Car is in Connecticut. Check your mail for some pictures. (You're in MD, probably neighbors with my brother in Chevy Chase).

William,
Please send me your email address, it's not on your profile.
-Ed

Numbers all look very good. I would buy it and run it as is, for the warrenty period. If it survives that upgrade it. The only problems in upgrading first is you cloud any warrenty issues if you work on it.

Thanks Jack. I did buy it and have already started doing the tensioner update on it as well as a clutch before I put it in. Seller said this won't void his "no knock" warranty.
I'm sure I'll be posting back with some more questions.

I'm still questioning the #5 leakdown of 19%!

I am trying to locate a fitting for the compression tester hose to hook up to compressor to see if I can hear where air is leaking from. Will try to put some pressure through #5 ASAP. Is 19% a horrible number on this cylinder? I thought that <10% was good, 10-20% was O.K., and >30% may mean more serious problems brewing. I think that I may have to get engine in car and run it for a while to get accurate results before I begin ripping top end apart.
Anybody agree?

19% is NOT a horrible number. Don't sweat it. Check the valves for proper adjustment, and run it. Even if it is a real leak number, ie valves or rings, you would NOT feel the difference if it were corrected. Run the thing for a year and check again. IF it is worse you will most likely find the source, most likely it will not be worse and the engine will continue to run for a long time. An other check you should do is a simple compression test, if all cylinders meet the std requitements, ie variation from cylinder to cylinder and have enough compression ( remember to have the throttle wide open when you measure compression) then everythings hunky dory.

Snowman, what is normal compression numbers?
Before I rebuilt my engine it was in the 185-190psi. (All but #4 see below.)
This was higher than anything I have seen posted.
I rebuilt it because I broke the top ring on #4.
I only have about 1500 miles on the rebuild and have not rechecked compression or leakdown yet. The P&C's are the same. (They met all wear specifications.) #4 had a dent where the intake valve contacted the piston. I believe there was a clearance problem and although it was not catistrophic I think when the valve was touching the piston it twisted the piston slightly and over time this resulted in wearing out the top ring to the point it broke.
Ed, let us know what you find with the air test. I found my fittings at one of the local home center. I put a T where the gauge goes and added the air hose fitting to the 3rd hole. This actually made a very imprecise leakdown tester. I turned the regulatior on my compressor to 100 psi and watch the needle on the compression tester. If you compaire #5 cylinder to the others you will not really get an accurate test to compair to anything else that is posted, but you will be able to make comparisons between one cylinder and another. The most important thing is to try and figure out where it's leaking if it is. If you can you can maybe fix it now or keep an eye on it as you drive the car.
A real leakdown tester can be had for less than $100 or you can build one from instructions found on this site. (Although there are a lot of variarions and discussions about how one should be built.)
Let us know what you find out!

Normal compression numbers are whatever the mfg says they should be. I would have to look up the number for the year and engine. I would give you the number but do not have the info handy at this time.

A pressure of 185 to 190psi sounds completely normal for a 9:1 compression engine. Cams can affect the number a lot so if your cam is different your compression may be lower if the duration is longer, or higher if the duration is shorter than stock.

Variation between cylinders is most important. For the case of 185psi the variation should be less than 18 psi. or about 10% of the reading. I haven't heard of one cylinder ever being a lot higher than the others ( unless its worn out and most holes are say 80psi and one is 180psi, but never most being 180 and one being 250 or something like it) Typically a worn engine might be say 130 to 150 psi and a BAD hole 80psi or less. If the typical is 185 to 190 and one hole is say 150, then a leakdown test is in order. The leakdown will tell you if the lower number is due to valves or rings . If you do a wet compression test you may be able to determine the porblem IF its the rings, otherwise its back to the leak down test. With the leakdown test you can tell if its the rings, valves, or both by listening to where the air is leaking out.

A general observation I have made about compression testing and leakdown testing is; Both are necessary to determine the true health of an engine. Its possible to have broken rings and pass a compression test, but a leakdown will show a huge problem. A leakdown can show a potential problem that isn't real, ie more than 10 % but less than 50%. a solid compression test, with the RIGHT numbers, eg 185 to 190 vs say 150 psi would indicate a problem with the test, not the engine.

Bottom line--- compression tests, leakdown tests are not black and white. If the tests are perfact, or real bad, all is well, but if there is some greyness, then experience is the key to determine what they really mean.

Thanks for the lesson!
The PO of my car kept very good records.
Most of the early work was done by dealers or very good shops that recorded the results on the tickets.

This car had the original 930/10 9.8:1 CR
Unfortunately in 1996 he opted to install a suposedly rebuilt 930/16 9.3:1
Kept the 930/10 CIS system on it which later was bastardized because of confusion and an inexperienced wrench.
I just rebuilt this engine. I carefully measured everything and found most things withing wear limits so the bottom end was refreashed with standard bearings. The ALUSIL P&C were fine so just new rings. The heads got redone with new valves, springs and guides. (I ported out the intake side to match the larger runners of the 930/10 CIS. The cams are stock with no evidence of regrind.
I have no idea what version P&C's are on the engine. I tried to get them identified, but it seems the only way to do that is to do the CC test.
I'm not racing so I wasn't worth the $$ to have someone do this.
(They are a stock CIS piston except I don't know the CR.)
I timed the cams to the 930/10 specs.

Snowman, in addition to the factors you listed above I have heard that the cam timing also has some effect on the compression readings.

With the age of these cars, and many of them have been rebuilt over the years, It's not likely many of them are box stock and would match any documented Compression numbers. What's more important is the knowledge of the particular engine (age) and the relationships between the reading of the 6 cylinders.
Both test are valuable. It's also good to map the results over time. This record is valuable in making the decision to rebuild before a catostrophic event takes plece.

Snoman, thanks again for the lesson.

Yes Jack, thanks for the pointers.
I attempted to get some pressure through #5 tonight but was hassled by the check valve inside the end of my compression tester hose....so I rigged up another air hose with the 14mm plug extension from the compression tester and put some air through. With #5 at mark on crank pulley, it sounded like air was coming from the spark plug area, while compressor regulator set to 20lbs pressure, losing pressure at 10 lbs per 12 seconds..........which leads me to believe I need to get a "REAL" setup to do this test. I'll see if I can find a leakdown tester here locally and RETRY. I'll keep you posted.

I have, however, been working on doing the tensioner update as I think this needs to be done as a safety precaution prior to installing engine Just got parts today, however, timing chain covers I received (from a Carerra I was told) do not have holes for oil thermo-time switch in left and temperature switch in right. Can I have these machined into them and what are the specs to do so?

My compression tester has a valve like in a tire stem. You can get the gadget to remove it at most auto stores. A leakdown tester will be harder to find.

Make sure #5 is at the top with the valves closed. If thay arn't now rotate the crank one revolution. You can also check your rocker arms if you have your valve covers off. They both should be on the back side of the cam and you should feel the clearance by wiggling them.
If there is no clearance you may have found your problem!
Adjusting your valves now would be a good idea anyway while the engine is out. 10 Times easier! If they are adjusted too tight the valve may not be closing all the way.
Most leakdowns are done at 100psi so don't be afraid to crank up the regulator.

On the covers, do they have the flat spots where the holes need to be drilled? If so any machine shop should be able to do this. They can take the diameter and thread dimensions off the temp switch or just take in your old covers.

I'm supprised they didn't come with the holes in them. You learn something new every day. I only have the hole in the lefdt cover for the thermo time switch because I don't have the lambda control CIS.

Yes, it does look like it has a tire-like stem in it. I'll get the tool and do that. When doing test, should crankshaft mark for #5 line up exactly with the mark on alt housing (top dead center)? I'm assuming that this is when all valves are closed for the cylinder....I guess I'm confused with what you mean by rotating the crank one revolution. (To get to #5, I rotate crank until rotor lines up with mark on housing to get me to #1 TDC, then rotate clockwise until I get to the 4th 120 degree mark past #1).

I plan on doing a valve check/job at this point as well as checking the cam timing...just got tools I need. Adjusting cam timing looks a little intense in nature, so I'll only do it if it looks like it's off.

Also, do I need to use new nylock nuts and washers on timing chain covers and valve covers when I reinstall........looks like it is recomended, but having trouble finding these items anywhere (Pelican does not sell the TC cover washers and nuts!)?

Yes the covers have the flat spots where holes need to go.....PO of engine included this kit with my engine purchase...all in kit is new except for the covers which he pulled off a Carerra, and the banjo fitting hollow bolts and washers. I also believe I need to acquire the oil line brackets on both sides that hold lines steady to cover (vibration reduction).

www.mcmaster.com

Try these guys for hardware. They are pretty inexpensive.
You should be able to find the locally at a good hardware store.

Since you are going to adjust your valves and maybe set yopur valve timing go ahead and take your valve covers off now.
Rotate the engine and watch everything work.
You will get the hang of it especially when you put your dial gauge on and watch the valves open and close.

You may be at the right spot for #5 but it's real easy to make sure. Grab the rocker arms if they both wiggle then you are. If one or the other is tight you are in the wrong spot.

You'll get the hang of it as you follow the sequence for adjusting your valves.
The most difficult thing about cam timing is trying to understand the procedure. Once you get everything set up you'll get the picture pretty fast. The second important thing is to make sure the chains are tight and both sides are the same.

When you get to that point let me know.

Put the air on it and look for leaks before you adjust anything. That way you will have a baseline.
Also record your cam timing before you adjust the valves.
The valve adjustment on #1 intake and #4 intake are criticle to the cam timing. If they are not adjusted right then the cam timing will read that it is off but this may just be due to the valve adjustment being tight or loose

Thanks Bill. What is the best material/type of nut and washer for this application...
It looks like the closest thing they have is a nylon insert nut but the max temp rating is 250 degrees.....is this too low (both for timing chain covers and valve covers)? Also, what material is best, ie. steel, stainless steel, brass, etc.?

There is a lot of discussion about this.
My engine never get's that hot.
I think I would worry if it was the exhaust studs.
Do a search. You will find a lot of opinions.
I wonder if the differen colors on the nylon inserts mean something?
I've seen clear/white blue and red.

Yeah, me too. I'll check it out.
(I hate the shopping part of doing this rebuild!)
Thanx

You should drive it now. Since carbon may have gotten between a valve and seat, do not adjust any valves tighter. Check them though, and back off any that are tight. Then put the engine in the car and drive it. With whatever new clutch pieces you need. Make all those other decisions after you see how it runs.

Should I simply check and adjust to .004 spec?

Also, I had a chance to create the setup for putting pressure on cyl #5. With pressure, I could hear what sounded like air coming through the left timing chain cover (I have covers off right now). It seemed to be holding pressure though. With Bill's setup as directed above, pressure gauge read 92 PSI with compressor set at 100. Could this be a bad ring? I listened at exhaust and injectors and did not hear anything there.

bump

Sounds pretty good if it's holding 92 psi cold.
If this was the real leak down tester it would mean 8% loss. Right up there with the others. (Not Bad, good!)
Did you do the leakdown at the seller's place before or after you ran the engine? Hot or cold.

If your hearing no air at the intake or exhaust then the valves are holding. The only other place is past the rings and like you said you herd it comming from the left chain case.
Remember the test you did is not very precise or accurate. Did you compaire it to the other cylinders? That would give you a relative comparison between the cylinders.

Like Superman said it's likely that some carbon got stuck in one of the valves on your initial test. If it did it's probably gone since the valves are holding.

Like he said, make sure there are no tight valves and get it running.
Do the tests again after some driving and adjust the valves then.

Good luck!
Did you figure out what to do about tapping the holes in the chain case covers for the sensors?

Bill,

The leakdown at seller's place was done warm after running engine. I did not compare to other cylinders yet....will try to do this weekend.

Do you think I should adjust valves before I install and run it or after? It looks like it would be tougher to get to them after installing. Since it was run prior to purchase, would there be carbon stuck in valves still, preventing me from adjusting them properly?

As far as the chain covers go, another stumbling block....see my thread on that here:

http://forums.pelicanparts.com/911-engine-rebuilding-forum/137247-oh-man-switch-holes-chain-covers-wrong.html

On the positive side, I just received a large order of parts from Pelican today....hoping to get the following done this weekend:

Timing chain update, valve adjust, check cam timing, clutch (new Sachs Power Clutch Pelican Super Kit), and Pelican tune-up kit.

I'm also having an issue with the fuel filler neck that I got with car that doesn't seem to fit the replacement left front fender. See my post on this....maybe you have a suggestion: http://forums.pelicanparts.com/porsche-911-technical-forum/136723-sc-fuel-filler-neck-fender.html

Thanks much,

-Ed