View single post by Esprit2
 Posted: 03-15-2019 09:34 pm
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Esprit2

 

Joined: 05-01-2005
Location: Minneapolis, Minnesota USA
Posts: 575
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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