Power & Heat Exchangers

[emcon5]

Originally posted by kach22i
My first concern is: was the cam timing messed with inadvertantly while upgrading the tensioners. That would be neglect, verses abuse if they bent valves in the procedure.

Changing tensioners shouldn't do anything to the cam timing. As long as you keep the chain tight on the cam sprocket, (I used zip ties) there is no reason to even look at it.

The invoice says "adjust cam timing", why did they do this, and what exactly did they do? Changing the cam timing can alter the power curve of the engine, advancing the timing helps for low RPMs, retarding it helps for high RPMs. Here is a hare-brained theory: Timing chains stretch over time, which would have the effect of retarding the cam timing. If they returned it to stock you could lose some top end. Whether you could tell the difference without a dyno, I don't know. I would think it would have to stretch a lot for it to be noticable though.

I don't see chain ramps on the invoice, which is suprising. Holy ****, $127 for spark plugs?

chrisp, there is a "clutch kit" listed on the invoice.

Tom

[jstgermaine]

kach22i-

I'm in Battle Creek, if you are ever in the need of space to do some DIY my lift and shop are always available!!

[kach22i]

Monday I will be taking my car into P.A.T., to see if the Cam timing is correct (another $220). I can not go on driving without knowing for sure.

If my cam timing on #1 and #4 is alright (I think that's what Mike said), then it's the end of my main concern, which is potential engine damage due to poor cam timing.

Checking this is something EuroTech (Tim Pott) has refused to. A responsible person double checks their work.

I can live with less than stellar performance due to other causes and figure out what they did wrong later.

When it comes time to do the heat exchangers, I might take up one of the generous offers made. Thanks, you guys are the best.

[palle7688]

You can check if valves are bend by doing a leakdown test.
Piston a top dead center of compression stroke and add compressed air through the ign.plug hole, with an adapter, a bend valve will show by hissing noise in either exhaust or inlet (or oil breather hose if a piston worn)
Take care when holding the crankshaft dead center as compressed air will try do turn/crank the engine.
Same thing is done to small aircraft piston engines on regular basis.
With 2 pressgauges, one for inlet press, one for actual press in cylinder you know the leakage. I do not recall the procentage allowed.

[kach22i]

palle7688, thank you for the information.

I might pay for an extra hour of shop time just to have peace of mind that my top end has not already been damaged. Then again if the cam timing is not off, the valves still could of been damaged during the chain tensioer installation. I better have both checked.

In for a dime, in for a dollar.

[emcon5]

Originally posted by kach22i
I might pay for an extra hour of shop time just to have peace of mind that my top end has not already been damaged.

If the top end is damaged, I would think you would know it. Pistons hitting valves is not a quiet event.

Then again if the cam timing is not off, the valves still could of been damaged during the chain tensioer installation. I better have both checked.

No they couldn't. I am not trying to be an dick here, but it really sounds like you don't understand what the tensioners do. Each timing chain is on 2 sprockets, one on the layshaft, one on the cam. All the tensioner does is pushed against a third sprocket to keep the chain tight. When you change the tensioner, all you need to do is keep the chain snug by some other method (like zip ties) so it stays on the same teeth on the cam/layshaft sprockets. As long as the chain doesn't slip a tooth, it is impossible to damage the engine by changing tensioners.

Even if it does slip a tooth, the only way to damage the engine is by starting it.

Timing the cams is not required, because there is no reason to even touch the cam bolt (or nut depending on year). For more info on what is involved in this job, check out the tech article.

Call the shop and ask "I see on my invoice you adjusted my cam timing. Can you tell me why you did this? Where were they set before? What did you set it to?"

Tom

[jchatfield]

George:

Your story sounds very frustrating and I must admit that the prices for spark plugs ($117) and ignition wires set ($334.00) are harsh. I bought a set of Magnecor reds - the best - for $120. Also, the stock oil cooler is expensive at $1200+ Not Eurotech's fault, but you can pick these up used for $250 all day long.

That said, I must relay my positive experiences with Tim Pott. I cannot believe that he condones shoddy work or cannot/ will not make it right. Maybe he has a new employee or some other explaination.

I used to own a rustproofing and quick oil change shop in Ann Arbor (State & Ellsworth area - sold in 1996 - now called Choice q Lube) and owned a 1987 944S at the time. I knew Tim Pott and had a professional relationship with him, in fact, we discusssed me doing his customers Porsche oil changes so did not back up his shop - I declined, because 911's cannot be done in 10 minutes and I did not want the liability. Anyway, when I bought my 1987 944S in 1996, somebody else did the PPI and then I took it to Tim to install Yellow Koni's up front and do the whole timing chain/ balance shafts thing that 944's require. Tim blew me away with his Porsche knowledge and sold me the Koni's at no mark up (professional courtesy). He found a dozen important items that the PPI missed. He did the most through inspection of the car I have ever encountered - even found a shoddy repair on one of the wheels where the lug nut goes and went over his findings in detail with me.

Then Tim really saved me. In 1997, my engine was making some strange noise and I had it towed from Royal Oak all the way to Ann Arbor so Tim could look into it. He found that the timing chain tensioner had failed and ground off the teeth to my 2 cams and the repair bill was like $4,500! I questioned his findings (did not want to believe) and he gladly showed me the car - it was just as he had described - ruined cams and a lot of work. I was very lucky it didn't jump timing! I had just gotten out of grad school and couldn't afford to fix it, so Tim told me where to located used parts. He put these in for me and got me back on the road for like $2,900.

Tim encouraged me not to fear these cars and I subsequently learned to work on my own Porsche, replacing the rear shocks, power steering rack (twice!) front control arms, muffler and other items. I sold that car and bought my 1972T in 2000. This car is not my daily driver, like the 944 was, but I'm proud to say that it has never been to a mechanic, save for alignment. I have replaced brakes, door stays, ignition, spark plugs, adjusted valves, installed sway bars/strut braces, rebuilt Weber carbs, installed updated seats & seat belts, sterring wheel. The list goes on and on. The point is, if you have the time, old 911's are really simple cars and there is not much that you cannot do yourself with the guidance of this board and wayne's two books (101 projects and the engine rebuilding book).

However, if you take your car to a wrench in the A2 area, Tim Pott and Eurotech would be my first choice, hands down. I knew all the A2 shops (in 1993-1997 anyway) and PAT had a good reputation. There were a lot of good shops in that area, but only PAT & Eurotech for Porsche's.

I have not talked to Tim in seven years, but a guy generally doesn't go from knowledgable & honest to ignorant and devious.

Good luck with your car and I wish you the best.

Jim Chatfield
1972 911T

[kach22i]

Originally posted by jchatfield
I have not talked to Tim in seven years, but a guy generally doesn't go from knowledgable & honest to ignorant and devious.

Jim, you are not the only loyal customer of Tim's willing to speak up for him. A guy named Will over at RennList feels the same way. I told Will he was free to call Tim and fill him in. He did!

Tim called me on 4/8/04 and offered to check the cam timing. I accepted and droped off the car at 5:00PM.

He asked me if I have had any problem with my projects as an architect, and I said yes. What do I do about them? I take car of the probem if given the chance.

It's funny he called me when he did, I was in the middle of the biggest problem I have had to deal with in a while. I am usualy so on top of things that I just dont have any problems, just small fires to put out. This one however was due to a client changing their mind on the type of window, and the builder resizing per new window type on this own (casements and single hungs don't come in the same sizes). They were too small, 2" to narrow, and almost 5" to short. Its not much of a sunroom if its more wall than window - so we are taking them out and upgrading them at no extra charge.

The clients problem, is my problem even if the people I work with keep me out of the loop. We work together to fix problems before they are real problems all the time. That's my dirty laundry, we all have some.

[vash]

squeaky wheel gets the grease. squeaky wheel telling other potentially squeaky wheels, about a bad grease supply....? crap i lost my train of thought, good luck.

[kach22i]

UPDATE:
True to his word, Tim Pott/EuroTec checked all of his work again. In addition he replaced the points and tweeked the ignition timing. Oh what a difference!

It's nice to see someone stand by their work and not give up, perhaps next time it will go more smoothly.

I only drove the car a little while, from the shop to my house, a ten minute drive (with side trip into an industrial park-low traffic area). However I can tell that the car moves like it lost 500lbs (like it used to). Now it takes off when you hit the gas, and not just thinks about it for a half second.

The low end seems to be back, and the top end too. The mid band has more meat in it.

The car has pep to it and is more fun to drive.

It was sad to have my old Geo Tracker more respondsive than the Porsche, now nature is back in equaliberium.

On the invoice (no charge) there is documentation (good sized paragraph) all about the oil leaks. There is much debate on-line about switching an old car to synthetic oil, but eventually I will need a re-seal job and some tranny work. It leaks too much the way it is for my taste, after warming up it leaks pretty bad on to both heat exchangers (been told it's not the new valve covers)- not something it was doing last fall. Thinking about changing the oil back to regular and seeing what happens.

PS: The cam timing is within spec's, that was not the problem afterall.

[jstgermaine]

I am glad things worked out for you!!

[jchatfield]

I'm glad it all worked out for you and I'm happy to see Eurotech get a clean bill of health. Pay attention to his notes about the leaks. My notes were always spot on and revealed what some current problems were. There are usually various solutions (low $ up to high $, owner fixes vs. hired wrench fixes) so ask Tim and describe the leaks to this board as well and I'm sure you will get a ton of helpful suggestions and insights. Leaks are a pain, but sometimes not too harmful, othertimes maybe a fire risk. Also depends how much cabin smoke you are willing to deal with! Check out wayne's book on "common oil leaks" and hope yours is one of these, which you can fix with some help from the book and this board.

Most of all, enjoy your car! There are some awesome drives our your way. Try Huron river Drive out towards Dexter.

[jdowty3]

Glad to hear it all worked out for you Kach22i. I grew up in Ann Arbor (3rd grade thru college and beyond, 22 years in total) and plan to move back to the area in a couple years. I'll actually be living in Hell, MI. I would have been back this year but fate brought me a job I couldn't turn down. I had planned on showing my SC at "Porsches To Pinckney" this year but I'll just have to be a spectator (if I can return for a vacation at all). I look forward to meeting all the SE Michigan Pelicanites one day soon.

[emcon5]

Originally posted by kach22i
UPDATE:
True to his word, Tim Pott/EuroTec checked all of his work again. In addition he replaced the points

Save yourself future headaches:
http://www.pelicanparts.com/catalog/shopcart/911M/POR_911M_911REC_pg19.htm#item

Tom

[MotoSook]

So your power issue was points related....correct?

Change the oil back to dino oil...the leaks will improve. There is no need to run Synthetic unless you don't plan to change your oil every 10K+ miles...or if you are really running hot. In that case, get an external cooler, and then use dino oil, the money you save buying dyno oil will pay for the cooler.

[kach22i]

Originally posted by emcon5
Save yourself future headaches:
http://www.pelicanparts.com/catalog/shopcart/911M/POR_911M_911REC_pg19.htm#item

Tom

I saw that in the Tweeks catalog too. Does it work? I will go that rout if the distributor stem "O" Ring ever goes, or if performance slips on it's own.

The points were replaced and the ignition timing redone, I suspect right back where it used to be, probably out of original spec. What ever works, you go with, right?

I know already this old car is a handful for anyone. If I save another $15,000 and sell her maybe I'll get a Boxster (just kidding).

[azasadny]

kach22i,

I'm glad things worked out for you! I hope we can meet some time as I'm in Wyandotte, MI Try to get to Pinckney the last weekend in July for the "Porsches to Pinckney" event, it's alot of fun! Take care!