Lotus Breaths Again!
Discussion
Friday she fired up briefly then flooded on a biblical scale. Checked float specs and all was in order (carbs were completely rebuilt). Sunday we were blessed and she fired right up. Carbs needed to be sinked and the link that connects the two carbs also needed a good bit of adjustment before it would idle smoothly.
Got wonderful oil pressure, a BIG relief. Both water and oil thermostats work perfectly.
So, after 1.5 years of not running, I'm pleased. It runs better than ever. Just a few more adjustments.
My question: The cam belt flutters on throttle up and then coming back down. Sounds like a prop when the pilot feathers the throttle. This couldn't be normal or is it? The semi-automatic tensioner is as far as she will go. I can almost rotate the belt 90degrees.
There are oil leaks too. On the front cover and cam housings. I used the red 'stuff'. All surfaces were cleaned properly before application. Any advice before I take it apart.
Once we get all these leaks fixed and adjustments completed the body can go back on.
Thanks!
louis
83 Turbo
Got wonderful oil pressure, a BIG relief. Both water and oil thermostats work perfectly.
So, after 1.5 years of not running, I'm pleased. It runs better than ever. Just a few more adjustments.
My question: The cam belt flutters on throttle up and then coming back down. Sounds like a prop when the pilot feathers the throttle. This couldn't be normal or is it? The semi-automatic tensioner is as far as she will go. I can almost rotate the belt 90degrees.
There are oil leaks too. On the front cover and cam housings. I used the red 'stuff'. All surfaces were cleaned properly before application. Any advice before I take it apart.
Once we get all these leaks fixed and adjustments completed the body can go back on.
Thanks!
louis
83 Turbo
lwasson said:
(Snip)... My question: The cam belt flutters on throttle up and then coming back down. Sounds like a prop when the pilot feathers the throttle. This couldn't be normal or is it? The semi-automatic tensioner is as far as she will go. I can almost rotate the belt 90degrees.
There are oil leaks too. On the front cover and cam housings. I used the red 'stuff'. All surfaces were cleaned properly before application. Any advice before I take it apart.
Louis,
Congratulations on getting the engine running. It sounds like your big battle is won.
Carb balance will have a big influence on how smoothly the engine runs at idle, and low end performance. The carb barrels have to be balanced of course, but the linkage coupler is where the biggest error usually occurs. A 4-tube manometer really makes that easy. Especially on a turbo with a closed intake plenum that prevents the use of a Uni-Syn or similar intake mounted flow meter.
A little timing belt flutter isn't unheard of. I've seen a little flutter fairly often. But sounding like a feathered propellor??... that seems excessive. Maybe I'm getting caught up in your flowery description... ;-)
Considering the condition the DPO left the tensioner in before you got to it, and not being able to check it directly myself, I guess I'm a little concerned by your discription and hesitant to say, "Yeah, that's cool".
When you say you can twist the timing belt just about 90 degrees, is that with the engine cold and before it's been run for the first time that day? Or is it after the engine has been warmed up. The belt tension is significantly tighter once the engine is warm. All tensioning specs, Burroughs, Clavis, Krikit, finger twist... assume the engine is cold and has not been started yet that day. A 90 degree twist (or gauge check) cold indicates correct tension. A 90 degree twist after the engine has been started and warmed up will result in the timing belt being way loose. Way loose would lead to more flutter.
You upgraded to HTD belts but kept the spring loaded, semi-automatic tensioner, correct? That's a little unusual in that most folk doing the HTD upgrade go all the way and install the eccentric tensioner as well. I'm not saying there's an issue. I've just never run into that combination before (HTD & semi-automatic) and I don't know if there is an issue. I talked to Jeff at JAE about it and he's in the same boat. Hasn't run into the combination and doesn't know if there is a "known issue" to be avoided. Could you send a video tape of the belt flutter to me or post a video clip?
The red sealant? Loctite/Permatex 518? That's good stuff. If the sealed joint itself is leaking, I doubt that it's due to a poor choice in sealants.
Exactly where are the leaks? You mentioned the front cover and the cam carrier. By front cover, do you mean the front main seal cover? If so, is the source of the leak around the perimeter of the housing where the red sealant is, or is oil oozing out of the running joint between the rubber lip seal and the crankshaft? That's two separate issues. Unfortunately, all the belts and pulleys have to come back off to resolve either one.
Great care must be taken while installing the lip seal over the end of the crank. It's a stretch fit of soft rubber over a square steel corner, and it's easy to nick the lip seal in the process. Stretch wrapping the end of the crank with vinyl electrician's tape will help protect the lip. Let the tape half overlap the end of the crank and then stretch it tightly enough to cause it to semi-wrap around the corner. Smear it with oil to make it slippery. The vinyl will protect the lip from the sharp corner on the end of the crank journal.
Oil the seal and shaft before installation so the seal doesn't start up dry. Friction will melt it before engine oil circulates to it.
Then once the seal is on the shaft, the housing must be centered about the shaft before tightening the bolts. Just letting the weight of the housing hang on the lip seal while the bolts are tightened will result in a distorted seal. Too tight on top and too loose on the bottom. Same with the rear main seal... any leak evident out of the bell housing?
Lotus has a special tool that facilitates installation of the seal and centering of the housing. JAE has them available for rent... or sale.
The cam carrier leak. Is it a cover or seal leak, or is it the other issue we talked about offline. The bad Heli-coil in the head so you couldn't properly torque the carrier to the head? Is it still leaking there?
A little Hylomar will help seal the top cam cover. The brass bolt hole covers should all have fresh O-rings.
The front lip seals on the cams have the same issue with installation... don't nick the lip. But you don't have to worry about centering them. Again, Lotus has a special tool to facilitate easing the seal onto the end of the shaft.
Post here, or feel free to continue contacting me via e-mail. You have my home phone, don't you?
Regards,
Tim Engel
Lotus Owners Oftha North
Once we got the engine running we found numerous little problems that had to be addressed. So the cam housings cam back off to fix an oil leak, the front plate was removed to fix another oil leak, alternater casing needed some machining so the belt would run true, new bushings for the automatic belt tensioner so the cam belt would also run true. I think that was all this go round?
Got everything back together and cranked her up and the cam belt still flutters pretty bad. The semi-automatic belt tensioner was moving a good bit in attempts to control the belt. I got a Krikit gauge and it reads 70lbs and that's with the tensioner set at a low tension. I know thats high but I plan on setting it higher to see if that stops the wild flapping. The belt is running straight with the new bushings.
Before we cranked the car I noticed a crack on the plastic oil pressure line going into the block. I cut out the bad section and then we spent quite a bit of effort trying to put the line back on the barbed fitting. The plastic line is old and hard and all attempts to soften the plastic didn't work. I rigged a softer but wider ID line to the fitting and 30sec after the engine cranked a LARGE puddle of oil was running out from under the engine. The rigged line had popped off. What a mess!
I'll get a new line today and then play around with the tensioner. It would not surprise me if a new manual adjusted tensioner is in my future.
Has anyone else noticed their cam belt wildly flapping or what might be causing it besides low tension?
Thanks!
louis
83 Turbo
Got everything back together and cranked her up and the cam belt still flutters pretty bad. The semi-automatic belt tensioner was moving a good bit in attempts to control the belt. I got a Krikit gauge and it reads 70lbs and that's with the tensioner set at a low tension. I know thats high but I plan on setting it higher to see if that stops the wild flapping. The belt is running straight with the new bushings.
Before we cranked the car I noticed a crack on the plastic oil pressure line going into the block. I cut out the bad section and then we spent quite a bit of effort trying to put the line back on the barbed fitting. The plastic line is old and hard and all attempts to soften the plastic didn't work. I rigged a softer but wider ID line to the fitting and 30sec after the engine cranked a LARGE puddle of oil was running out from under the engine. The rigged line had popped off. What a mess!
I'll get a new line today and then play around with the tensioner. It would not surprise me if a new manual adjusted tensioner is in my future.
Has anyone else noticed their cam belt wildly flapping or what might be causing it besides low tension?
Thanks!
louis
83 Turbo
About 15 years ago when I rebuilt my 907 engined Elite, I had a problem later diagnosed as a bent Auxiliary Shaft (oil pump/distributor) which manifested itself by allowing the woodruff key to eat away at the inside of the pulley which would wobble slightly off centre but not immediately apparent to the naked eye.
You might also like to check the Crankshaft pulley as if it's not sitting square but held tight by nut and washer (so not immediately visible) it will revolve eccentrically and give you a slack then tight belt. My Excel had a badly fitted crank pulley - it was forced on by the previous owner, had cracked but did not fail...
Good luck,
Dave.
You might also like to check the Crankshaft pulley as if it's not sitting square but held tight by nut and washer (so not immediately visible) it will revolve eccentrically and give you a slack then tight belt. My Excel had a badly fitted crank pulley - it was forced on by the previous owner, had cracked but did not fail...
Good luck,
Dave.
lwasson said:
...Has anyone else noticed their cam belt wildly flapping or what might be causing it besides low tension?
Thanks!
louis
83 Turbo
Louis,
The belt flapping is pretty normal, although there is a point at which it is a problem. One reason for the flapping is that the tension is not homogenous, but differs considerably when measured at various points in it's circumference. This is why Lotus added the little guard over the intake pulley (to avoid the belt slipping when it flaps and also why Lotus specifies the measuring point as the run between the Aux and intake pulleys). Once past the exhaust pulley, the tension between the Ex pulley and crank pulley is considerably lower. The tensioner is designed to minimize these differences, but is reactive and so some flapping occurs. If the tension is fine, you're probably ok, but considering the damage potential of a slipped belt, if in doubt, rebuild the tensioner paying particular attention to the springs which can fatigue over time.
Happy Motoring! ...Jim'85TE
davejw said:
(Snip)... I had a problem later diagnosed as a bent Auxiliary Shaft (oil pump/distributor) which manifested itself by allowing the woodruff key to eat away at the inside of the pulley which would wobble slightly off centre but not immediately apparent to the naked eye.
Louis,
Dave's observation about the possibility of a bent Auxiliary shaft is worth checking out. I also experienced that once. It did cause the Woodruf key to hog out the bore as he noted, and it did cause a wobbly aux pulley. I don't recall the belt "flopping" a lot more than usual… but it could be a possibility worth investigating.
As I mentioned to you offline, forward a *.wav file or a VHS tape so I can take a look at the belt in action. What one guy calls flopping, someone else may call normal vibration. So far I've been reacting to your concern about the belt flopping and envisioning the belt really moving around. But I don't have a way really quantifying vibrating/ buzzing/ flopping... all highly technical terms... ;-).
If it flops enough to go through sympathetic vibration periods during which the belt suddenly moves dramatically more than the baseline, and if it makes a pronounced low-frequency buzz while doing so, then you definitely have cause for concern.
Regards,
Tim Engel
Lotus Owners Oftha North
Minnesota, USA
Thanks to all!
Yep, the low frequency buzz is a concern. Got the oil line fixed tonight and fired it up briefly. Had a play to go to tonight so I will check everything tomorrow. I've still got a big mess to cleanup from all the oil and I believe I noticed a little oil coming from the cam housing at the same point it always leaked. Arrrrgggghhhh!!!!
Thanks again,
louis
83 Turbo
Yep, the low frequency buzz is a concern. Got the oil line fixed tonight and fired it up briefly. Had a play to go to tonight so I will check everything tomorrow. I've still got a big mess to cleanup from all the oil and I believe I noticed a little oil coming from the cam housing at the same point it always leaked. Arrrrgggghhhh!!!!
Thanks again,
louis
83 Turbo
I have to confess I read the KritKit gauge wrong and that was the reason for the flopping, slapping, prop fluddering, low frequency buzzing cam belt. OK you can stop laughing now. I really don't know why I wear glasses or ever learned how to read?? Doesn't seem to do me much good sometimes but you just shake your head, laugh and go on. I did check out all your suggestions and the pulleys are all fine. No slack anywhere, just in my brain.
OK...to the good news! The engine is running sweat. Got the timing in good shape and slowly getting the carbs adjusted, but she is running so good. Throttle response is great. Jim, or anyone if you could give me the product info for 4 port manometer that would be great.
Just when everything was going so good, POW!!!! and she went dead and wouldn't fire back up. What the heck is going on??? Coil is firing but the timing light was eratic one #1 plug and didn't fire on #2. Took the distributer(sp?) cap off. It check out and the rotor too. Looked around some more. When putting the cap back on the distributer pulled out. What had happened was the collar that crimps down on the distributer was too loose from all the tweeking on the timing and allowed the distributer to backout resulting in loud bang. Got all that fixed and she is running sweat.
Next to shifter adjustment. Good to finally work on something else besides the engine. I must say something here for Steve and SJSportcars. The shifter mod they sent me was not fabricated properly and he sent me another at no charge for the mod or shipping from the Mother Country. Not sure we're suppossed to endorse a commercial company, but thanks Steve! Back to the shifter. We noticed the shifter would hang just a little at a certain point. Took the crossgate out and took a good look at where one of the fingers had been re-welded. It was off alignment few thousandth and clipping a part of the gear shift in side the tranny. Ground it down just a little and now it shifts very smooth. All the new shift linkage bushings really help.
It has been a good Lotus day and McLaren won too!
To date the suspension rebuild is complete, engine just about there and shift linkage should not take much more to finish. Body just about ready to go back on!!
Thanks again to everyone for your time and help. I couldn't do this alone.
louis
83 Turbo
PS: Not responsible for errors in spelling or grammer.
OK...to the good news! The engine is running sweat. Got the timing in good shape and slowly getting the carbs adjusted, but she is running so good. Throttle response is great. Jim, or anyone if you could give me the product info for 4 port manometer that would be great.
Just when everything was going so good, POW!!!! and she went dead and wouldn't fire back up. What the heck is going on??? Coil is firing but the timing light was eratic one #1 plug and didn't fire on #2. Took the distributer(sp?) cap off. It check out and the rotor too. Looked around some more. When putting the cap back on the distributer pulled out. What had happened was the collar that crimps down on the distributer was too loose from all the tweeking on the timing and allowed the distributer to backout resulting in loud bang. Got all that fixed and she is running sweat.
Next to shifter adjustment. Good to finally work on something else besides the engine. I must say something here for Steve and SJSportcars. The shifter mod they sent me was not fabricated properly and he sent me another at no charge for the mod or shipping from the Mother Country. Not sure we're suppossed to endorse a commercial company, but thanks Steve! Back to the shifter. We noticed the shifter would hang just a little at a certain point. Took the crossgate out and took a good look at where one of the fingers had been re-welded. It was off alignment few thousandth and clipping a part of the gear shift in side the tranny. Ground it down just a little and now it shifts very smooth. All the new shift linkage bushings really help.
It has been a good Lotus day and McLaren won too!
To date the suspension rebuild is complete, engine just about there and shift linkage should not take much more to finish. Body just about ready to go back on!!
Thanks again to everyone for your time and help. I couldn't do this alone.
louis
83 Turbo
PS: Not responsible for errors in spelling or grammer.
Louis,
Good news about getting the belt right, you really dodged a bullet there I hope you realize...whew!
For the 4-pot manometer, contact Matthew Cooper at EuroCarb Ltd. - www.dellorto.co.uk - You're looking for the Morgan CarbTuneII, it comes complete and should ship right away. It will be one of the most used tools you have for this car, that and your specs and the krikit..
Happy Motoring! ...Jim'85TE
Good news about getting the belt right, you really dodged a bullet there I hope you realize...whew!
For the 4-pot manometer, contact Matthew Cooper at EuroCarb Ltd. - www.dellorto.co.uk - You're looking for the Morgan CarbTuneII, it comes complete and should ship right away. It will be one of the most used tools you have for this car, that and your specs and the krikit..
Happy Motoring! ...Jim'85TE
Louis,
Congratulations on getting the belt issues sorted out. I'm glad the solution was as easy as reading the correct scale. Sometimes the simple victories are the best.
You can also purchase a Carbtune II 4-tube manometer direct from the manufacturer, John Morgan:
<morgan@carbtune.com> e-mail
<www.carbtune.com/> website
I purchased mine from Eurocarb a couple of years ago and can't fault Matthew Cooper's service. But the Morgan website is the best place for info on the product, and you can order online.
The Carbtune ships in a cardboard box that has served as my storage container for a long time. It works, but no class. The Morgan website also offers a taylored, padded nylon carry case. I've got one and it's a huge improvement over the old box.
Also check eBay and eBay.co.uk for Carbtune auctions. There are usually several going at once... some pretty cheap.
When you get ready to balance the carbs, I can send you a procedure document as a file attachment if you wish. Otherwise, you subscribe to the turboesprit list on Yahoo. I've posted the file there as well, so you can download it at your convenience. Go to the Files section, scroll w-a-a-y down to the "Tech" folder. Then open the "Engine" folder.
Regards,
Tim Engel
Lotus Owners Oftha North
Congratulations on getting the belt issues sorted out. I'm glad the solution was as easy as reading the correct scale. Sometimes the simple victories are the best.
You can also purchase a Carbtune II 4-tube manometer direct from the manufacturer, John Morgan:
<morgan@carbtune.com> e-mail
<www.carbtune.com/> website
I purchased mine from Eurocarb a couple of years ago and can't fault Matthew Cooper's service. But the Morgan website is the best place for info on the product, and you can order online.
The Carbtune ships in a cardboard box that has served as my storage container for a long time. It works, but no class. The Morgan website also offers a taylored, padded nylon carry case. I've got one and it's a huge improvement over the old box.
Also check eBay and eBay.co.uk for Carbtune auctions. There are usually several going at once... some pretty cheap.
When you get ready to balance the carbs, I can send you a procedure document as a file attachment if you wish. Otherwise, you subscribe to the turboesprit list on Yahoo. I've posted the file there as well, so you can download it at your convenience. Go to the Files section, scroll w-a-a-y down to the "Tech" folder. Then open the "Engine" folder.
Regards,
Tim Engel
Lotus Owners Oftha North
You're right Jim, I did dodge a bullet. This car has dodged enough trouble all ready in its mysterous past and I don't need to add anymore.
Thanks for the manometer info. I'll order it today. I'll take Tim up on his offer for the correct procedures. Make it simple...as I've clearly demostrated my inablility to read instructions. Ha!!
louis
83 Turbo
Thanks for the manometer info. I'll order it today. I'll take Tim up on his offer for the correct procedures. Make it simple...as I've clearly demostrated my inablility to read instructions. Ha!!
louis
83 Turbo
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