Part number for seals

[janszott]

I'm about to change the timing belt on my 91 SE and I thought I
should also replace the front seals at the same time.
Is there a cross ref to Timken or SKF or do I need to buy from Lotus?
I figure I'll need front Crank seal and both Cam seals.
(I already have the tensioner bearing)
Anything else I should do besides the other belts?

Jan
91SE
Canada

[lotusguy]

janszott said:

I'm about to change the timing belt on my 91 SE and I thought I should also replace the front seals at the same time. Is there a cross ref to Timken or SKF or do I need to buy from Lotus? I figure I'll need front Crank seal and both Cam seals. (I already have the tensioner bearing) Anything else I should do besides the other belts? Jan 91SE Canada

Hi,

Front Seal is a Lotus part. The Camshaft Seals are generic. Pull one and take it to any bearing shop, they should be able to fix you up.

As far as other work is concerned, you might think about doing the pulley swap (Aux. Pulley for the Intake Cam pulley) for slightly better breathing and be sure to check the waterpump weep hole for any signs of leaking. Better to do the pump now if there's any indication it's starting to go as the access will never be better. Also, a check of your valve clearances is easiest with the belt removed. From TDC, turn the crank back 90° bringing all the pistons halfway down their bores, then you can spin the cams freely to check clearances. Once complete, turn crank back the same 90° to TDC before reinstalling the belt. Happy Motoring! ...Jim'85TE

[janszott]

Thanks Jim
I don't have the history on the car so how do I know if the pulleys weren't already swapped? I'd hate to swap them back to stock.

BTW, your email address in your profile seems to be invalid.

Jan
91SE

[B16 RFF]

lotusguy said:

janszott said: I'm about to change the timing belt on my 91 SE and I thought I should also replace the front seals at the same time. Is there a cross ref to Timken or SKF or do I need to buy from Lotus? I figure I'll need front Crank seal and both Cam seals. (I already have the tensioner bearing) Anything else I should do besides the other belts? Jan 91SE Canada Hi, Front Seal is a Lotus part. The Camshaft Seals are generic. Pull one and take it to any bearing shop, they should be able to fix you up. As far as other work is concerned, you might think about doing the pulley swap (Aux. Pulley for the Intake Cam pulley) for slightly better breathing and be sure to check the waterpump weep hole for any signs of leaking. Better to do the pump now if there's any indication it's starting to go as the access will never be better. Also, a check of your valve clearances is easiest with the belt removed. From TDC, turn the crank back 90° bringing all the pistons halfway down their bores, then you can spin the cams freely to check clearances. Once complete, turn crank back the same 90° to TDC before reinstalling the belt. Happy Motoring! ...Jim'85TE

Enlighten me. How does changing the pulleys improve the breathing? If you are changing the cam timing in some way, why not say so.

[Muck Savage]

The intake and exhaust pulleys both have a red alignment dot on the outer gear ring and have a 110 deg timing. You aux pulley (for pump/chargecooler etc.) may have a green alignment dot which is a 104 deg timing gear. I thinks there's a blue dot one too but can't remember what degree offset it is.

The Euro spec cars had green dot gears but the US spec ones had the red dot ones for emissions reasons. Jim is more the resident expert on this but suggests the engine runs best on a 104 intake and 104 exhaust cam timing. The intake timing is by far the most important gear in deciding power output etc.

You can also get an adjustable cam gear to change the timing an arbitrary amount which gives more refined control of timing if you want that, but swapping the gears has 0 parts cost as you have one already.

michael
2000 111s
ex-1995 S4

[lotusguy]

Muck Savage said:

The intake and exhaust pulleys both have a red alignment dot on the outer gear ring and have a 110 deg timing. You aux pulley (for pump/chargecooler etc.) may have a green alignment dot which is a 104 deg timing gear. I thinks there's a blue dot one too but can't remember what degree offset it is. The Euro spec cars had green dot gears but the US spec ones had the red dot ones for emissions reasons. Jim is more the resident expert on this but suggests the engine runs best on a 104 intake and 104 exhaust cam timing. The intake timing is by far the most important gear in deciding power output etc. You can also get an adjustable cam gear to change the timing an arbitrary amount which gives more refined control of timing if you want that, but swapping the gears has 0 parts cost as you have one already. michael 2000 111s ex-1995 S4

Micheal,

You summed it up well. Lotus retarded the cam timing on US cars, swapping to a 104 MOP (Maximum Opening Point) is the design spec for the 9XX engine. Right again that the intake swap yields the greatest (or more noticeable) difference.

But, while positive and recommended, you have to take care and not raise your expectations unreasonably high. You're never gonna get Lambo V12 power from a mere pulley swap. Valve timing alone simply won't gain that much. For greater gains, you need higher lift and duration and now you're talking a new cam profile.

IMHO, the improvement gained does not justify the purchase of either a stock Lotus pulley, or adjustable pulleys either. But, since it's essentially better performance for free, go for it. Happy Motoring! ...Jim'85TE

[bojangles]

how does the swap affect the emissions,, we Canadians have to do bi-annual smog tests.. no sense setting up for failure....
Bruce s4s

[Muck Savage]

As for emissions, I know of at least one PH'er who has run the advanced 104 cam setup on an S4 and passed US emissions testing in Missouri I believe. He had an adjustable gear on so he could adjust it back in a few minutes if necessary, but didn't have to. He just might comment too if he reads this, Mark?

If you have the cat on I don't think the cam will affect emissions too much if the engine is warm and all your basics engine essentials are well taken care of, i.e. injectors, plugs, oil/air filter etc.

michael.

[Lotusguy]

Muck Savage said:

As for emissions, I know of at least one PH'er who has run the advanced 104 cam setup on an S4 and passed US emissions testing in Missouri I believe. He had an adjustable gear on so he could adjust it back in a few minutes if necessary, but didn't have to. He just might comment too if he reads this, Mark? If you have the cat on I don't think the cam will affect emissions too much if the engine is warm and all your basics engine essentials are well taken care of, i.e. injectors, plugs, oil/air filter etc. michael.

Hi,

Be careful when you start talking cam timing vs. cams. There is a '104' cam (which I run in my Esprit) and cam timing of 104° MOP (Maximum Opening Point).

For the cam, '104' is merely an arbitrary designation. It does have a specific lift - 0.412" and duration - 272° and is a more agressive Street Cam over the stock (for my Esprit) '107' Cam which has a lift of 0.378" and a duration of 272°.

Lotus also has used a '110' cam. There is also a popular aftermarket cam called the DS2 (named after the Lotus Engine Tuner and creator - Dave Smith). The DS2 cam would be classified as an agressive Street or Mild Race cam and posesses both a higher lift and longer duration.

Switching to this cam also requires a switch to the thin walled, short (0.500") valve springs because the stock valve springs are too long and will fully compress before the cam lobe bottoms out. The short valve springs may also be used with the '104' cam. I switched to these when doing the cam swap primarily because they are cheaper than replacing with stock Lotus valve springs. Remember, the cam opens the valve, but it is the valve springs which close it smartly and tightly making the proper seal. The stock valve springs are really only good for about 40k mi., when they fatigue and their performance, and consequently the head's, begins to suffer. This is why I replaced mine at 45k mi.

The '104' Pulley is a true designation and does allow the cam to reach it's Maximum Opening Point (MOP) at 104° of Crank rotation.

These are often confused, but are two distinctly different animals. Happy Motoring! ...Jim'85TE

PS. Due to the larger valves on the S4s, swapping the pulleys has much less effect and may not be worth the effort.

[arium]

40K only for valve spring life? Oh my!

Here I was just thinking I'd got everything sorted out (including popping the rear quarters and resealing) and had a little time left to actually enjoy the car.

Seriously Jim, should I be replacing valve springs (intakes and exhaust) soon, as I'm at 35K. I was actually thinking of doing the turbo as it occasionally seems to want to put a dribble of oil in the intake plenum.

Where do I best get these bits from? I'm in Canada and have great luck getting through to Dave Bean but JAE usually gets me an answering machine. Plus they JAE doesn't seem to return calls. Bean is very quick but I sort of sense that they don't always try and 'find' that part for the extra sale. They got the order for 2 parking brake cables, 2 door seals, pedal pads, and a few other bits but lost out on the fact that they only had one of my rear quarter windows. I ended up doing that locally. Mind you JAE didn't get any cause they don't return messages or emails. Now I sit here horrified about trying to obtain bit from these two guys very soon to plan for my next 'resceduled' maintenance.

So far I've done all my emmisions stuff, new cat and exhaust, clutch & cover, timing belt, replaced ALL electronics in the GM department including the computer but was currently only thinking about turbo seals and possibly injectors. Other than that I thought that with a 35K mile car I should be okay. I was hoping not to touch the top or bottom end unless an oil/coolant leak or something along those lines neccessated the motor being pulled. Then I'd get the little piggy redone.

It is just that yanking the head at 40K seems like a fairly costly proposition. Certainly not something I was expecting. Obviously that'd be the time to redo all seals since it wouldn't make sense just to do this bit of pm.

Steve
1989 non SE
s/n 2506 - see there were a five b4 mine that year

[Lotusguy]

arium said:

40K only for valve spring life? Oh my! Here I was just thinking I'd got everything sorted out (including popping the rear quarters and resealing) and had a little time left to actually enjoy the car. Seriously Jim, should I be replacing valve springs (intakes and exhaust) soon, as I'm at 35K. I was actually thinking of doing the turbo as it occasionally seems to want to put a dribble of oil in the intake plenum. Where do I best get these bits from? I'm in Canada and have great luck getting through to Dave Bean but JAE usually gets me an answering machine. Plus they JAE doesn't seem to return calls. Bean is very quick but I sort of sense that they don't always try and 'find' that part for the extra sale. They got the order for 2 parking brake cables, 2 door seals, pedal pads, and a few other bits but lost out on the fact that they only had one of my rear quarter windows. I ended up doing that locally. Mind you JAE didn't get any cause they don't return messages or emails. Now I sit here horrified about trying to obtain bit from these two guys very soon to plan for my next 'resceduled' maintenance. So far I've done all my emmisions stuff, new cat and exhaust, clutch & cover, timing belt, replaced ALL electronics in the GM department including the computer but was currently only thinking about turbo seals and possibly injectors. Other than that I thought that with a 35K mile car I should be okay. I was hoping not to touch the top or bottom end unless an oil/coolant leak or something along those lines neccessated the motor being pulled. Then I'd get the little piggy redone. It is just that yanking the head at 40K seems like a fairly costly proposition. Certainly not something I was expecting. Obviously that'd be the time to redo all seals since it wouldn't make sense just to do this bit of pm. Steve 1989 non SE s/n 2506 - see there were a five b4 mine that year

Steve,

Yup, 40k mi. is really the life of the valve springs. Both Barry Spencer and Ken Gray @ Dave Bean confirmed that to me. Same is usual for guides (which double on the 9xx engine as the seals).

I venture to say that the majority of Esprits out there with >40k mi. on the clock are on the original springs. And even though they are operating at diminished efficiency, the fact that the engine is blown probably masks it to a great degree.

The springs themselves are less than $100USD, in fact they were $86USD from DBE, vs $180USD for stock Lotus springs. It also cost me about $100 to have them installed. I have a guy here locally who is young, but very skilled, and is a one-man shop. He did the entire head (three angle grind, lapped the valves and seats, installed new guides and springs, checked for cracks, pressure tested and cleaned) for under $500. This was against estimates from the premier import machinist starting at $1,400. I know the #1 independent Mercedes Mechanic in the area (National reputation - 5 month wait to book your car) and he recommended this guy (Aaron's Precision Machine), says he sends all his head work to him. After 10k mi., the car still runs very fresh. He'd probably do cross border work, I could find out if you're interested, or call him yourself at Aaron's Precision Machine [phone]. No affiliation yada, yada.

Are you certain it's your turbo and not the oil recirculator which is spitting into your plenum? This recirculates crankcase fumes (containing a certain amount of oil) back through the air cleaner where it is drawn into the intake trunking, through the compressor and into the intake plenum. This is often mistaken for blown turbo seals. Happy Motoring! ...Jim'85TE

[arium]

Thank you for the info:

I had associated any 'head off' work being at least in the 2k range. Mostly the idea of the Re and Re of the head itself and whether or not it was done in situ would be an expensive proposition. I will check and see if anyone in the canadian pacific northwest can do similar work for that sort of pricing. Seems extremely reasonable and I do have a business address south of the border where things can get dropped off.

You raise again a very good troubleshooting tip. NEVER make assumptions. I'll certainly hook in an oil trap tank ala the quad four's to see if the oil migration into the intake plenum repeats. It could very well be that little french peculiar valve thingy with it's mesh and screens thats spits oil. More later.


I'll call Ken early this week and order the springs for sure. Seems like a bargain and hopefully I can team them up with some other sort of candy the car needs. Seems that the important thing is having the bits on hand when you need them.

Thank you again,

Steve
1989 non SE

[janszott]

Well I bit the bullet and ordered the seals from local Lotus dealer. CAD$180 (USD$132)
I took them into a bearing supplier and he crossreferenced them = about $7 -$10 each
Front Crankshaft - 52x68x8VTF
Camshaft - 1.50x2.25.0.313 (CR14938)

Jan
91SE Canada

[Dr.Hess]

Thanks, Jan. I'll put them on my cross ref list.

Dr.Hess

[lotusguy]

Jan,

Good Call! I too went to a bearing shop and sourced the camshaft oil seals when I did my rebuilt a couple years ago, they were actually better quality than the OEM parts, cheaper too. Happy Motoring! ...Jim'85TE

[MikeyRide]

Lotusguy said:

PS. Due to the larger valves on the S4s, swapping the pulleys has much less effect and may not be worth the effort.

My S4s has both 104 pulleys. It's a nice off-idle improvement. I have a very steep driveway that the car used to crawl up just barely over idle, even foot to the floor. Now I easily reach too-fast-for-the-driveway speeds.

"Worth" is subjective, of course, but it was worth it to me. The little bump in power makes the car more pleasant in around town slow going.

[lotusguy]

MikeyRide said:

Lotusguy said: PS. Due to the larger valves on the S4s, swapping the pulleys has much less effect and may not be worth the effort. My S4s has both 104 pulleys. It's a nice off-idle improvement. I have a very steep driveway that the car used to crawl up just barely over idle, even foot to the floor. Now I easily reach too-fast-for-the-driveway speeds. "Worth" is subjective, of course, but it was worth it to me. The little bump in power makes the car more pleasant in around town slow going.

Mike,

As you say, Worth is a very subjective term. I'm glad you found a useful increase. I am a little shy about exagerating the merits of the pulley swap because I've had too many people come back and say it is barely noticeable - one wonders what they expected.

And, most of the effect is found in the lower regions of the tach, exactly as you described, but considering the inherent lack of lowdown grunt in a 4 banger, every little bit helps. Happy Motoring! ...Jim'85TE

[MikeyRide]

lotusguy said:

I am a little shy about exagerating the merits of the pulley swap because I've had too many people come back and say it is barely noticeable - one wonders what they expected.

Agreed. It's not going to overcome the inherent limitations of: 2.2L, 8.5:1 compression, tallish 1st gear. It just makes a little more of what you're starting with. My semi-controlled "driveway test" is the only thing that lets me say that it absolutely is an improvement, even if small.