Engine Repair

[jpolubin]

I have a '87 TE with 45,000 miles with two questions.

1) I was recently told by my friendly local Lotus Service mechanic that the reason for my engine backfire condition (after it warms up) is because I have a great deal of vacuum leaks around the engine heads and block and they would charge $5000 (US) to repair with new gaskets. Is it easy enough to repair this myself? I do have some mechanical skills

2) How does the valve lifters get adjusted

Thanks!
Jim

[lotusguy]

I have a '87 TE with 45,000 miles with two questions.

1) I was recently told by my friendly local Lotus Service mechanic that the reason for my engine backfire condition (after it warms up) is because I have a great deal of vacuum leaks around the engine heads and block and they would charge $5000 (US) to repair with new gaskets. Is it easy enough to repair this myself? I do have some mechanical skills

2) How does the valve lifters get adjusted

Thanks!
Jim

Jim,

I doubt that gaskets are the sole cause of your backfire condition. I strongly suspect that valve clearances may also be a factor.

As far as replacing the gaskets yourself, this is very doable. I rebuild my entire engine/tranny last summer on my '85 and nothing was really hard. But, you will want to pull the mottor. This is tedious, but with a friend or two is not that bad. You can rent an engine hoist and equalizer.

If your choice is paying them $5k, why not rebuild the motor yourself? For $5k, doing your own assembly/disassembly, you can have a valve job done, the head milled, rebuild the waterpump, rebuild the turbo, install a Dump valve, replace all gaskets, bearings, hoses, belts and have some money to spare. There are really no special tools required.

As far as valve clearnces, you must pull the valve covers, check the clearances with a feeler gauge (spec. is 0.005"-0.007" for intake and 0.010"-0.012" for exhaust). Record the gap between the heel of the cam lobe and the cam follower (tappet) for each valve (this will almost always be smaller than the minimum acceptable gap as the valves drive themselves deeper into the seat with time). You must rotate the engine so that the cam goes 'off cam' on each valve before taking the measurement. This is easiest done by putting a socket on the crank and rotating it by handd with the sparkplugs removed to ease the turning torque required.

Next you have to remove the timing belt and cam tower to expose the timing shims. Measure each shim using a caliper and add this value to the gap values you recorded earlier. Now, subtract either 0.007" for intake or 0.012" for exhaust and this is the size shim you need to replace the existing ones in order to re-establish the correct timing gaps.

Reassemble the head and re-check the gaps, if all is correct, you are done, if not, you have to check them again.

This can also be done with the engine in the car, but is very difficult to get accurate measurements. I would not do it with the engine in the car. Let me know if I can offer further assistance. Happy Motoring! Jim '85TE

[jpolubin]

THANKS! Looks like this summer I will have my hands full! Jim