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 Posted: 03-14-2019 02:52 pm
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flatlanderep
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Location: Charlotte, North Carolina USA
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So it has been a couple months from my last post. I had AAA tow the car to a British car repair shop in Durham, NC in late Jan. After much effort on adjusting timing, car started but would not continue, cough, sputter, die. Shop diagnosed problem with valve clearances and ended up grinding the shims.Made some adjustments to idle and replaced cam timing belt. Also replaced the cam cover gaskets with silicone gaskets. It is running fairly well but shop wants to change Dellorto chokes to smaller size to improve idle and make acceleration smoother. I need advice on the charge for the work done i.e., labor for valve work, adjusting & confirming valve clearances, installing new plugs cam cover gasket,cam timing belt, choke cable, radiator hose came to $2,700. Seems excessive to me and there is not itemized labor on the bill. To replace the chokes in the carbs, the estimate is $800-1000 with parts estimated included at $200. My other concern is that there was no estimate provided. What do others think about these charges?
Steve

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 Posted: 03-15-2019 07:29 am
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Tim Murphy
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To re shim the valves requires the head be removed and reinstalled. That is a lot of work, sometimes has to be done two times to get clearances right Also requires a new head gasket which is a $100 part. Two things surprise me. One, in California, a written estimate is required before the work is done. Two, I have read or was told that you are not suppose to grind shims down as that weakens them. Not sure about that. Also, I think I suggested doing a compression check when you were having problems. That would have indicated some info on valve condition and valve clearances. The valve clearances can be checked at home, requires removing the valve covers and can be checked cold. JH repair manual gives the specs. In any case, the $2,700 seems high to me (all mechanic work seems high to me) but not terribly excessive. I have ZS's but the cost for replacing chokes in carbs seems high as I have read many post here where guys have done it themselves. Hopefully others here will have more experience with this type of thing. Good luck and take care.

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 Posted: 03-15-2019 03:49 pm
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gmgiltd
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Hi Tim, you don't need to take off the head to shim the valves - just the cam housings and they no longer use gaskets. It a fiddly time consuming job though especially if you are trying to get the clearances exactly the same and not just within spec - you may have to take them off and on more than once.
Gordon

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 Posted: 03-15-2019 05:58 pm
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redracer
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THIS IS A COPY FROM THE "FUEL PUMP" THREAD: LET"S KEEP THE COMMENT ON THAT PAGE SO WE DON"T HAVE ALL THIS DUPLICITY

The standard for valve shimming is 12 hours of labor; the Loctite #518 cam tower-to-head anaerobic gasket cement is a less than $15, the shims maybe $7/shim?, the cam cover gaskets(orange ones from JHPS) about $36, and the seloc washers around $18, so yes, you are paying a
lot(local hourly rate is $72.hour--yours may be higher??).
The valve shims should NOT be less than 0.060", or breaking of the shim is very likely(read $$$$$$$).
btw, someone posted taking the head off, but this is not necessary. I have shimmed many cars with the head on in the car(yes, there are a few tricks to making sure you don't lose a shim or nut down the oil returns).
In short, I would definitely find out what this person's hourly rate is and demand an itemized bill; you will likely need to go somewhere else
bruce

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 Posted: 03-15-2019 09:34 pm
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Esprit2
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Steve,

What is the shop's hourly rate ($$/hr). Don't be shy... ask. That's a fair question that you should have asked up front. In a large metro area, it could be $130-150 per hour, in which case it doesn't take long to run up a big bill.

I've only heard your side of the story, but from that point of view, it sounds to me like your mechanic is all too happy to run-up the bill. I'd be reluctant to open the door for him to do extensive work on the carbs.

Do you have any mechanical skills? Or are you going to be at the mercy of some mechanic, somewhere?

*~*~*~*
It's not uncommon to grind the valve shims by a thousandth or two, but they should not be ground to make big changes. The shims are case hardened, which means a relatively thin hard surface with a soft core. If you grind too much off of the thin hard skin, then the shim may very well crack... or worse.

The last time I purchased NEW valve shims from JAE (Lotus supplier), they were about $3.75 each. At shop rates, it would be much more economical to buy replacement shims rather than taking the time to grind them down to size.

The shims are the same as those used in the SAAB 99 2-valve engine, Triumph TR7, Jag XK 6-cyl (vintage 3.8 & 4.2 / XK-E), Cosworth and Coventry Climax. Shops that service those cars will usually have a supply on hand. I used to 'trade' shims one for one at a local (former) SAAB dealer. Free for a direct exchange, $3 each for any I took without an exchange.

As others have stated, it is not necessary to remove the cylinder head to shim the valve clearances. Just the cam carriers. With the exception of the cost of replacement shims and two cam cover gaskets, the task is pretty much all labor hours. And that can be significant.

*~*~*~*
What size are the Dellortos' current chokes? Dellortos were not stock in North America, so someone has added them; and that opens the door to all sorts of questionable choices. But, presuming the carbs are to standard J-H spec, the chokes do not need to be any smaller. They're already small compared to what Lotus used on their own 907s.

Eurocarb Ltd lists DHLA40 chokes at US$18.17 each (US$20.86 for DHLA45 chokes), and you'll need four. Replacing them will require dis-assembling the carbs, so you'll need a rebuild kit for two carbs at US$89.70 for a genuine Dellorto kit, or US$46.44 for a 'budget' aftermarket kit.

Rebuilding two Dellorto carbs isn't going to happen in 5 minutes. At shop hourly rates, plan on something in the $375 each range.

*~*~*~*
Lotus Flat Rate Manual for Front Engined Elite & Eclat
(Front engine models, so access is similar to the JH's)

0.3 hr - Engine Compression Check.

0.6 hr - Replace Belt Guard Top Section, only.
1.5 hr - Replace Belt Guard Complete (ie, remove & replace).

0.8 hr - Check Valve Clearances.
3.5 hr - Adjust Valve Clearances ('shim' the valves).

1.0 hr - Replace Camshaft Sprockets (both).

0.7 hr - Adjust Timing Belt Tension (including checking cam timing).
2.8 hr - Replace Timing Belt (my personal record on an Eclat is 45 minutes).

1.7 hr - Replace Timing Belt Tensioner.
Note: Does not include time for replacing the bearing(s). Add appropriate time if the bearing is replaced.
0.3 hr - Add this much if the Lotus ONE-PIECE Tensioner Bearing is Replaced.
Note: Early JH Tensioner Bearings are two separate ball bearings assembled into an outer roller ring. Time for replacement is considerably longer.

Regards,
Tim Engel

Last edited on 03-15-2019 09:51 pm by Esprit2

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 Posted: 03-16-2019 09:39 am
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Tim Murphy
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I apologize, I was wrong in saying the head had to be removed to re shim the valves. The only time I shimmed the valves was many years ago when I had a burnt valve and had to remove and reinstall the head. So I incorrectly remembered head removal as part of the process. Thanks to those that gave the correct information.

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