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It is the off-season and the forums have shown that many people have been or are going to be doing rebuilds.
If you would not mind sharing your thoughts and previous experiences, it would be helpful to the group.
Just to be specific, comments should regard customer service, cost, output results, items addressed (ie how detailed was the work, to what level was the motor rebuild, ie all new parts, some new parts, just a freshen, etc).
Thanks.
jonmca wrote:
[quote]It is the off-season and the forums have shown that many people have been or are going to be doing rebuilds.
If you would not mind sharing your thoughts and previous experiences, it would be helpful to the group.
Just to be specific, comments should regard customer service, cost, output results, items addressed (ie how detailed was the work, to what level was the motor rebuild, ie all new parts, some new parts, just a freshen, etc).
[/quote]
Whatever you do, don’t replace just the head. If the head gets replaced, clean out the piston ring grooves and replace the rings. Sigh.
Ranger wrote:
+1.
Not sure I have any hard evidence for this theory other than as soon as I rebuilt the head, the next race, the bearings in the bottom end gave way. Coincidence? Maybe. Or maybe the tightening of the head tolerances forced compression back down onto the block (blowpast the rings)? Whatever the case, the reason I say ‘+1’ is because if you’re going to go through the hassle of doing the head, you might as well do the block at the same time (minimum rings and bearings). “While you’re in there…”
I started a thread a few weeks back on rebuilding an engine and got a lot of good advice. One thing I did notice when I started to piece together all the parts for a rebuild it quickly started to exceed the cost of a used working motor. I put together over $1k in parts for an engine that cost me $150. No clutch or machine work factored in either.
I am interested in hearing more about why doing just head work could be bad. I was thinking I could afford to “freshen” the motor and deal with all the little oil leaks and not touch the bearings/rings/etc. if everything looked “OK”.
I did just the head over the last winter…spent $1k-1200 and ended up with 128-131hp…not sure of the cause but(good compressio, good leak down) but why take a chance. the motor got good gas mileage and I think from now on will be known as “the enduro motor”
How did I spend $1k on the head? New Cam, rocker shafts, rockers, springs, a valve or 2, guides, gasket set.
I think the best way would to be buy 3 Craigslist $500 cars and dyno test em and take the best one.
Al
Al has the best answer. The best engine that I’ve owned was a junkyard engine at 160hp. Then I blowed it up by making a number of errors.
Regards, Robert Patton
I don’t know what has happened with Scott’s engine, but I’ve never experienced a case where a good head job has resulted in an engine running worse. It may run no better if there are other serious problems, but it shouldn’t run worse just because of a head refresh. In this case I suspect something else is wrong. Especially since they had trouble getting the engine to run after re-installing the head.
I’m not sure that I’m buying into the “carbon into the piston rings” theory. If the rings were that packed up with carbon those cylinders should have been down on compression before the head job.
And while I’m off on an odd tangent…
Robert,
It seems obvious to me that your engine is flooding out on a warm start. Since a change in the DME and the AFM has no affect on that I have to wonder if the injectors are leaking while the car sits or if there’s some fault that is causing the injectors to be open rather than pulsing.
I did a full head rebuild with a junkyard bottom end, new main bearings, and assembled it myself. The motor put down 150rwhp/155rwtq and runs like a top. It even has a great curve to boot. YMMV.
JP
Thanks, Jim for all of your help and ideas. I’m going to continue to try and find an answer. Trouble shooting the #241 this past year has been trying. From the loose crankshaft bolts allowing the dampner to move and engine to sputter at high rpm to the latest…
Back to the original topic.
Regards, Robert Patton
I replaced just the head on my car and ran competitively for this entire past season. The bottom end had ~250k on it and I just replaced the valve guide seals and the gaskets. No rings no bearings.
my 2 cents
I’m no engine mechanic, but it would seem that when we are talking about engines that have between 150K and 250K miles on them, have been through multiple owners, junkyards, etc., who really knows what could cause all these failures. I doubt any of our engines (except maybe a few) have detailed maintenance records to accompany them. So you really never know what you’ve got with regards to all of the moving parts of the engine, until it breaks, then at least you can identify that part that was worn out.
I think continuous maintenance is the key. Run it till it quits, then go try and find another $500 donor car. Someone said this weekend that we will eventually run out of good used engines and have to start doing full rebuilds. Don’t remember who said it, but they are probably right.
John
drumbeater wrote:
[quote]I’m no engine mechanic, but it would seem that when we are talking about engines that have between 150K and 250K miles on them, have been through multiple owners, junkyards, etc., who really knows what could cause all these failures. I doubt any of our engines (except maybe a few) have detailed maintenance records to accompany them. So you really never know what you’ve got with regards to all of the moving parts of the engine, until it breaks, then at least you can identify that part that was worn out.
I think continuous maintenance is the key. Run it till it quits, then go try and find another $500 donor car. Someone said this weekend that we will eventually run out of good used engines and have to start doing full rebuilds. Don’t remember who said it, but they are probably right.
John[/quote]
I agree with the run it till it quits comment, my car has the original 12?k(I really have no idea) motor which has never been opened up and it dynoed 157 hp 158 tq last month. When you can buy a well broken in and loose 100k mile motor for $600 why pay to rebuild and get less hp? With no upgrades allowed, seems like a strong 100k-200k mile motor is going to give good power equivilent to built motors!! I’ve got a 175k mile motor out of an auto car that I am keeping as a spare.
I disagree with the running out of motors comment, Spending lots of time on various E30 forums, motors will be available for quite some time!!! Since more and more people are pulling perfectly good M20’s to swap in M50/52s and S50/52s. I would bet the E36 guys run out of motors before we do!!
Re:Motor Rebuilding 15 Hours, 18 Minutes ago
"I don’t know what has happened with Scott’s engine, but I’ve never experienced a case where a good head job has resulted in an engine running worse"
I have seen it, once. The good head job resulted in damage to the crankshaft when I drove into a telephone pole.
Al
FARTBREF wrote:
[quote]Re:Motor Rebuilding 15 Hours, 18 Minutes ago
I have seen it, once. The good head job resulted in damage to the crankshaft when I drove into a telephone pole.
Al[/quote]
Comming (no pun intended) from Al Taylor that quote is a dandy.
Regards, Robert Patton
Patton wrote:
[quote]FARTBREF wrote:
[quote]Re:Motor Rebuilding 15 Hours, 18 Minutes ago
I have seen it, once. The good head job resulted in damage to the crankshaft when I drove into a telephone pole.
Al[/quote]
Comming (no pun intended) from Al Taylor that quote is a dandy.
Regards, Robert Patton[/quote]
OMG that was funny. I must admit, I missed it on the first read. Very good Rev. 
Gasman wrote:
[quote]Patton wrote:
[quote]FARTBREF wrote:
[quote]Re:Motor Rebuilding 15 Hours, 18 Minutes ago
I have seen it, once. The good head job resulted in damage to the crankshaft when I drove into a telephone pole.
Al[/quote]
Comming (no pun intended) from Al Taylor that quote is a dandy.
Regards, Robert Patton[/quote]
OMG that was funny. I must admit, I missed it on the first read. Very good Rev. ;)[/quote]
But was it a good head job?
I can’t stress enough that good head work has to be done early. Because at some point a person gets married. And, well, that’s that.