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Yes, I've read about that. But I'm wondering about the compatibility of this approach with my LR super-mount engine mounts. Seems like using the LR Super Mount transaxle mount might be the safer option. After my recent experiences (waiting for the bill for leaving a 1700' oil slick on the track this past Saturday - imagine it will be well in the thousands of $$), I'm inclined to take the safest, most bulletproof approach to everything I do in the process of correcting what may be causing my current highly damaging symptoms.
Love the Urathane trick.. Did it on my racecar..AWESOME option... How many bags of speedy dry? At Watkins glen its $40 a bag...
Love the Urathane trick.. Did it on my racecar..AWESOME option... How many bags of speedy dry? At Watkins glen its $40 a bag...
5 bags. My worry is the length of the oil slick; I assume they charge by the foot. I was afraid to ask how much. It must have, at least initially, been a relatively slow leak, because my oil pressure light never came on, the gauge reading never fluctuated, I didn't spin or even lose traction - no indication whatsoever that I was leaking oil. I finally got a wiff of a slight burning smell, by which time i was near the pit exit, so I pulled into the pits immediately, and shut my engine off right away.
Do you think a urethane transaxle mount would play well with LR engine Super Mounts? The LR transaxle Super Mount just seems like the easy button...
Do yourself a favor and get the LR transaxle ultra mount. Your car isn’t stock. So why would you use stock mounts? The stock mounts are designed for the snobs that don’t like hearing road noise not the enthusiasts that want to race. https://www.lindseyracing.com/LR/Por...A-944-UTM.html
Well, I found out what happened, but I'm not yet sure how it happened. I took off my belt covers tonight, and the lower balance shaft's mark is definitely not lined up with the indicator on the belt cover - it's nowhere near 180 degrees off, though - it's maybe 40 degrees off. The top shaft is lined up correctly. But also, the belt is extremely loose, which is puzzling, because the nuts holding the tension adjustment cams are nice and tight. You can see in the photo below that my brand new BS belt's outer teeth are noticeably damaged from banging against the water pump pulley because the belt was so loose.
So, I'll be ordering a new balance shaft belt, and will try to figure out how it could have gotten so loose. I've done many belt replacements on this car in the 16 years I've owned it, and this one went the smoothest of any I've ever done - I nailed the belt tightness/clearance (actually deflection) very quickly, and I checked everything by turning the engine over several times, as I always do, so I'm pretty baffled. But at least I found the source of the vibration.
All of this makes me even more adamant about keeping the OEM engine mounts on these cars. You get so much buzzing and vibration from solid mounts, that the extra vibration from the mis-timed balance shafts probably was not noticed. It is possible or even likely that the vibration would have been noticeable with the OEM mounts.
And this is not coming from a "snob that doesn’t like hearing road noise"; my street-driven 951 has all spherical bushings, modified front spindles, and stiff springs and is set up for track use. But I also know that the disadvantages of the solid engine mounts far outweigh the advantages.
Also +1 for the urethane-filled factory trans mount----this is one of the single most effective modifications that I have ever done to this car!
All of this makes me even more adamant about keeping the OEM engine mounts on these cars.
I've always been a big proponent of the genuine Porsche engine mounts on these forums, they really are perfect in every way, quality-built and they last a long time. Nothing else comes close imo. I remember speaking to Albert Broadfoot a while back about the mounts he used/recommended for track cars and he always swore by the genuine mounts and used nothing else. Guy might not be as de-rigueur as he once was with the new batch of niche tuners out there, but you can't deny he build a ton of our engines and built them skillfully and successfully.
That aside, the Urethane trans mount mod is a little gift sent from heaven, not many times can you make a huge improvement to a stock part for so little cost and effort.
That's Great news that you found the issue! I have been working on the front of an engine and seen a Balance shaft move by itself with the belt off... You know, we are only human and sh$% happens... Glad you found it...
Im actually running the Crappy URO mounts (new of course) in the front and did the urethane trick on the Trans... 3 years now.. No Issue.. The only Drawback that I found is when you want to remove the RR half-shaft, normally there is enough movement in the stock trans mount to push the trans over just a bit to get clearance around the lol cooler loop... Not so one you do the urethane trick... a but more of a puzzle to get that shaft out... LOL...
I had the biggest issues with balance shaft alignment turns out there was something wrong with the markings on my 1986 turbo as the lower one was 180degree off (this was corrected in later models) . Issues i had was cracked oil pickup tube , ps and alternator coming loose and smashing tentioners into the ground. I also found loose bolts everywere in the enginebay on heat shields and cracked crossover pipes and exhaust. Next engine will not have that belt .
Just to be clear, I never installed solid engine mounts in my car - after considering them, I went with the Lindsey Racing Ultra-Mounts, which have quite a bit of rubber isolation in them, and appear to be very well made. The root cause of my problem turned out to be a loose balance shaft belt, which caused the lower BS sprocket to "free-wheel", probably creating all sorts of crazy harmonics, enough to back out the bolt holding the oil lines to the block, which is what caused the oil spill. I've received my new belt, and will be even more careful about installing it, and will leave the plastic covers off for awhile so I can monitor the belt's tightness and the BS sprocket aligment before venturing back to the track. I also plan to do the urethane-filled transaxle mount modification, after all the positive feedback I've received here about that mod. I'm sure my original, 28-year-old trans mount is long past its useful life.
I had the biggest issues with balance shaft alignment turns out there was something wrong with the markings on my 1986 turbo as the lower one was 180degree off (this was corrected in later models) . Issues i had was cracked oil pickup tube , ps and alternator coming loose and smashing tentioners into the ground. I also found loose bolts everywere in the enginebay on heat shields and cracked crossover pipes and exhaust. Next engine will not have that belt .
I have never heard of this, I mixed mine up because of the "U" and the "O" The upper and lower sprockets are the same... and it is possible to put that washer on wrong, exposing the wrong Letter... I dont even pay attention to that anymore and just line up the marks on the back...
I would never run without shafts... Thats just me.. Spoken to quite a few 44 guys who have not had good experience running without them.
I had the biggest issues with balance shaft alignment turns out there was something wrong with the markings on my 1986 turbo as the lower one was 180degree off (this was corrected in later models) . Issues i had was cracked oil pickup tube , ps and alternator coming loose and smashing tentioners into the ground. I also found loose bolts everywere in the enginebay on heat shields and cracked crossover pipes and exhaust. Next engine will not have that belt .
Originally Posted by GPA951s
I have never heard of this, I mixed mine up because of the "U" and the "O" The upper and lower sprockets are the same... and it is possible to put that washer on wrong, exposing the wrong Letter... I dont even pay attention to that anymore and just line up the marks on the back...
I would never run without shafts... Thats just me.. Spoken to quite a few 44 guys who have not had good experience running without them.
Yes it’s the exposure of “O” and “U” on the lower sprocket that sometimes gets folk and causes a 180 deg out of alignment and quite bad vibration at two distinct rpm ranges.
Unless I misread, I too cannot understand Adonay’s logic of not using the balance belt because he once didn’t fit it correctly and it caused issues. Those same issues and a few more will occur without the belt, the worst one not mentioned is a cracked fuel rail, pretty much fatal to the car and hopefully not the occupant too.
Yes it’s the exposure of “O” and “U” on the lower sprocket that sometimes gets folk and causes a 180 deg out of alignment and quite bad vibration at two distinct rpm ranges.
Unless I misread, I too cannot understand Adonay’s logic of not using the balance belt because he once didn’t fit it correctly and it caused issues. Those same issues and a few more will occur without the belt, the worst one not mentioned is a cracked fuel rail, pretty much fatal to the car and hopefully not the occupant too.
Well i am not sure about my engine anymore as the harmonics are different , Lighter pistons,rods and flywheel . I have a good friend that ran without shafts for 15 years now with no issues . Missalignment was done by a good shop btw that told me the 86 engine should have the lower mark reversed.
...I have a good friend that ran without shafts for 15 years now with no issues ...
A blanket statement like that is misleading. Whether a balance shaft delete works depends on many variables, addressing the pick-up tube, fuel rail and the loosening bolts are just a few. Can it be made to work well....sure it can if you address the likely issues. But simply running without shafts or the balance belt is not a wise move.
02-25-2020, 04:27 PM
