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Here’s a couple threads from Peerless@E30Tech.com He has a shop near LA. Is interesting to read about the kind of meticulous care that goes into a good engine builder. As opposed to some yahoo that will throw any ol’ timing belt on that is handy at the moment.
http://www.e30tech.com/forum/showthread.php?t=59017
http://www.e30tech.com/forum/showthread.php?t=77575
So maybe you thought this thread was going to be about me telling folks how to rebuild their motors the “right way”? Sheeze.
Ranger wrote:
[quote]IndyJim wrote:
Roger that, lol. Do the opposite of whatever I do/did.[/quote]
Isn’t this exactly what I tried to politely say a month and thousands of dollars ago?
Scott don’t take offense to this because you are my friend and lemons team member. But re-using an old timing belt on a $? rebuild was not a smart move!! Especially since they are so cheap. I’ve got a parts car sitting in a barn I would not even start due to aged TB. You know me from BF.c also and I challenge you to find a thread where that is deemed acceptable:unsure:
PS
I admire your determination. I have had an M20 block sitting on the motor stand waiting for love for over a year:(
Gasman wrote:
[quote]Ranger wrote:
[quote]IndyJim wrote:
Roger that, lol. Do the opposite of whatever I do/did.[/quote]
Isn’t this exactly what I tried to politely say a month and thousands of dollars ago?[/quote]
It’s all good. The sum of the “is my engine supposed to be clanking” and the “uh oh, the cam isn’t turning when the crank turns” episodes might indeed end up being $2k, but I know how to rebuild a motor now (although I’m no expert), and I can pull and replace a motor by myself. To some folks that would be no big deal, but to me it’s significant.
And I’m the one that figured out that the motor was fine when the engine builder wanted me to buy an oversize bearing and regrind my crank. I assembled the motor once with help and twice on my own during that effort.
Sure, if I had post Molitor to do over, maybe I’d a had a motor built for $4k or so. But if I’d a done that, I’d still be intimidated by removing my rocker arm cover.
A month from now I’ll be collecting data that confirms that our oil pumps run dry every lap. Then next year you’ll be replacing your bearings and want to talk about an Accusump. And I’ll have the answers because I figured it out this spring. We learn from our mistakes and our problems. It’s all part of the process. No sense getting down about it.
87isMan wrote:
[quote]Scott don’t take offense to this because you are my friend and lemons team member. But re-using an old timing belt on a $? rebuild was not a smart move!! Especially since they are so cheap. I’ve got a parts car sitting in a barn I would not even start due to aged TB. You know me from BF.c also and I challenge you to find a thread where that is deemed acceptable:unsure:
PS
I admire your determination. I have had an M20 block sitting on the motor stand waiting for love for over a year:([/quote]
Who are you debating with? I’m not asserting that reusing a tbelt is reasonable. Heck, I even made fun of it in the first post.
Experience tells a person what shortcuts they can get away with. And folks disagree all the time. One person tells me that I should replace my main bolts with very expensive ARP bolts, and another tells me that reusing my OEM main bolts is fine.
The book says don’t re-use head bolts, but an M20 specialty shop says you can re-use them a time or two if you torque them down with a different protocol.
The book also says don’t reuse a head gasket, but a very experience M20 guy says that there’s some conditions where you can re-use it.
The most experienced guy in the group that helped us with the Feb motor swap at CMP looked closely at one of my gently used tbelts and said “it’s fine, put it on”.
My point is that the world is full of shortcuts, even if there’s disagreement on them. Experience tells you what you can get away with and luck sometimes determines the outcome. I took a chance 2 weeks ago on the tbelt, that I would not have advised another to do, and I ran out of luck. No big deal.
Ranger wrote:
[quote]Gasman wrote:
[quote]Ranger wrote:
[quote]IndyJim wrote:
Roger that, lol. Do the opposite of whatever I do/did.[/quote]
Isn’t this exactly what I tried to politely say a month and thousands of dollars ago?[/quote]
It’s all good. The sum of the “is my engine supposed to be clanking” and the “uh oh, the cam isn’t turning when the crank turns” episodes might indeed end up being $2k, but I know how to rebuild a motor now (although I’m no expert), and I can pull and replace a motor by myself. To some folks that would be no big deal, but to me it’s significant.
And I’m the one that figured out that the motor was fine when the engine builder wanted me to buy an oversize bearing and regrind my crank. I assembled the motor once with help and twice on my own during that effort.
Sure, if I had post Molitor to do over, maybe I’d a had a motor built for $4k or so. But if I’d a done that, I’d still be intimidated by removing my rocker arm cover.
A month from now I’ll be collecting data that confirms that our oil pumps run dry every lap. Then next year you’ll be replacing your bearings and want to talk about an Accusump. And I’ll have the answers because I figured it out this spring. We learn from our mistakes and our problems. It’s all part of the process. No sense getting down about it.[/quote]
Again, I’m on year three with my motor and it runs very strong.
Ranger wrote:
[quote]Here’s a couple threads from Peerless@E30Tech.com He has a shop near LA. Is interesting to read about the kind of meticulous care that goes into a good engine builder. As opposed to some yahoo that will throw any ol’ timing belt on that is handy at the moment.
http://www.e30tech.com/forum/showthread.php?t=59017
http://www.e30tech.com/forum/showthread.php?t=77575
So maybe you thought this thread was going to be about me telling folks how to rebuild their motors the “right way”? Sheeze.[/quote]
I’d be interested to hear the cost and performance difference between this, and a factory long block ordered from BMW (plus core).
King Tut wrote:
I have an AllData print out that says a short block is $4796.57. I don’t have the long block price. AllData is a some database that independent shops tap into for pricing parts and labor for cars.
Gasman wrote:
[quote]
Again, I’m on year three with my motor and it runs very strong.[/quote]
I hear ya. I’m your buddy so I only wish well of your motor. But if your bearings are routinely running dry each lap, then the bearings are going to go. The fact that your motor is strong is irrelevant.
We’ll see down the road what happens. A couple of yrs from now folks might recall this whole issue as a mountain made of a molehill. Or they might recall it as the “that’s when we started getting serious about our bearings”. Time will tell.
Scott, first of all… i admire your resilience and persistence… must be that army training 
As worthwhile as some experience by trial and error is and I agree you never learn unless you make mistakes, i can tell you that as a complete newbie when it comes to building engines, I would never reuse head bolts, head gaskets or t-belt. Now, those maybe worthwhile risks/shortcuts to take when in a pinch but not when your rebuilding the motor and spending $$$ on it and spending more $$$ going to an event.
kishg wrote:
Ok folks, get off my back.
I’m not attempting to assert that taking shortcuts is a good idea. But the fact is that there are folks that have 25yrs experience in building M20’s that have their own ideas as to what shortcuts can be taken under what conditions. If you disagree with them, not even knowing what those “conditions” are, go find them and tell them that you know better then they do and that they are wrong.
I’m simply telling you that smart experienced folks have an extensive library of knowledge of what works and doesn’t work. Part of that is what bolts can be reused under what conditions, what gaskets can be reused under what conditions etc. etc. Those opinions exist. I’m not telling you that they are right or wrong, I don’t have nearly enough experience to determine right or wrong in hardly anything.
All I can do is watch, read, listen and ask questions. Ultimately I make a call based on information absorbed and my own judgement. Sometimes it works, sometimes it doesn’t. That’s ok, it’s all learning.
Can we pls move beyond the tbelt now? It’s just a few darn valves and rockers. I should be back in operation in a couple days. I’ve got a bunyon on my little toe that has been a pita for a decade. You want to talk about something significant, lets talk about that damn bunyon.
haha… i’m surprised you have not researched that bunyon to death by now it’s all good, wasn’t trying to needle ya… see ya in sept at CMP!
Ranger wrote:
Scott -
Through all your trials and tribulations, I have learned more about M20 engines than I ever thought I could. I am probably where you were two years ago - rather tentative with wrenches around the motor.
Since I am still learning, the one question in my mind – and I know you have satisfied yourself – is whether the timing belt failure was a cause or an effect? The way the teeth were ground down in one small section of the belt makes it look like the valvetrain stopped and the crank kept rotating or vice versa. Is that what happened?
What led you to conclude that the belt was the cause and not the effect?
Steve D.
Scott,
I have a little anecdotal evidence for you regarding re-using stock engine parts. I am having some luck with some (at least in the short term).
We just finished running an event at Sebring and the ambient temps were hot (heat index 110F). The point about the heat is that racing in this heat with stock engines and a factory oil cooler is as tough a duty we can ask of these engines.
It was the first time I had my car on the track in 6 months.
6 months ago in maybe 80F ambient temp I was losing oil pressure in turn 12 (long hard accelerating left hander). The light came on (I don’t have a gauge) and stayed on for about 2 seconds for the last 4 laps or the race or so. It was disconcerting as hell. I was worried that I had damaged the bottom end. So, I sent the oil off to be analyzed and ordered a crank scraper form Chuck Taylor.
Oil analysis came back with normal wear metals
While installing the crank scraper I had my mechanic “inspect” the rod bearings. He pulled off the cap on four of the rods (1,2,5,6) Everything looked like new so he put it back together using the same bearings and same rod bolts. This is a real no no in some books and it had me a bit concerned.
During this same visit to the mechanic we installed a new aftermarket replacement head. Why? My old head had been welded up once already (three broken rocker journals on the intake side. Prior to my owning the car by the way) and the machine shop guy did not feel good about welding and machining this head again. We did use new head bolts. At the same time, we installed newly reconditioned injectors (cores sourced from the junk yard) from RC engineering.
Within the last couple of months the car has been to the dyno twice where we did probably 15 pulls trying to figure out why it was running lean. The point is, 15 pulls in a hot Florida garage is hard work.
As a side note on the lean issue, It looks like it was the reconditioned injectors. The TPS was replaced, the fuel pressure regulator, filter, and pump were all also replaced. We had good fuel pressure at the rail but lousy A/F ratio and 133 hp and 143 ft lbs of torque. After struggling with this and with me at my wits end, at 4:00 Friday afternoon we put the original injectors back in the car and on a leap of faith I put it on the trailer and took it to Sebring. I was determined that I was not going to miss another event at my home track and I was going to use the old butt dyno to determine if the car was running OK.
I was a bit nervous thinking that I had a very lean A/F ratio, a new untested head, re-used rod bolts and bearings, and a new crank scraper so I took it easy the first session. The car still feels a little flat but it is competitive. It is still not as fast as the Black’s car though which has legal HP and torque. I am guessing that mine is now around 150 HP. The crank scraper also did its job as the oil light never flickered.
Time (and continued oil analysis) will tell if re-using the rod bolts/ bearings was a good or bad idea.
Since the car is still slow down the straights, I still have some work to do to get the max HP up. Since this aftermarket head is still an unknown I may still swap the 100K mile motor out of my convertible into the race car. Since you know how to do that now I may invite you down some time next winter to show me and the Blacks how it is done. OK?
Don
Don,you are a couple of steps behind Ranger, and a couple of steps ahead of Ranger.(In terms of your dyno experience.)
I would encourage all to continue to learn about this part of the sport/hobby.
Some of the fast guys are fast in the car.
For some it’s off track prep.
Some have it going on in both areas.
Electrically:
Did you try different AFMs when testing?
Different ECUs?
Oxygen sensor on or off?
Mechanically:
What are the compression numbers?
What are the leakdown numbers?
Go forth and learn both on track and off track.
Regards, Robert Patton
