> Jensen Healey & Jensen GT Tech > Engine & Transmission > Seeking shims and answer on blocked oil drain |
> Jensen Healey & Jensen GT Tech > Engine & Transmission > Seeking shims and answer on blocked oil drain |
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smcmanus Member 
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I'm looking for the following valve shims: .080, .082, .088, .089, .095, .095, .097, .098 If anyone has some to spare I have others to swap or will purchase from you. I previously posed a question about the exhaust cam case aft drain being intentionally plugged with some type of epoxy. I cannot see how this is a good idea. Well maybe rust inhibition promoted by the heavy oil coating on the bottom side of the car is good. This car has been apart before and the perp obviously didn't have access to a manual or this site. Thanks Steve Attachment: jhcamoilhole.jpg (Downloaded 42 times) |
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Jensen Healey Super Moderator 
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On three of the four cam carriers that I have the hole you speak of is not there. There is an aluminum web in it's place. The fourth is open on both ends. I have seen the epoxy plug on the cam carriers that are on my running engine. Just run it the way it is unless you have a good reason to change it. Kurt |
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Chris E Member
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I'm guessing that restricting the oil return is a quick fix from the factory for extra cooling in the vicinity of #4 cyl. (search other threads for info on improving coolant circulation & restricting oil flow) Chris |
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smcmanus Member
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The result of this drain hole being blocked is that the cam housing fills almost completely with oil. With this hole blocked the oil has to reach the level of the front upper drain hole before it returns to the pan. When I pulled the cover I'm guessing a quart of oil dumped out. If this is desireable I will leave the glob in place. If not, I will remove it. Thanks Steve |
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Judson Manning Member 
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Leave the epoxy in place. That was a 'fix' done to the early castings, later castings (mkIII aka JH5) are all solid. The design was later revised with the introduction of the 910. This 'fix' was done to combat the cams in early engines from siezing in the cam journals. Additional 'fixes' include changes to the cam-to-journal clearance, and revisions to the oil delivery to the cam itself. Oil does pool in the cam cover which contributes to the leakage problem, but it's vital to keep certain parts of the valvetrain lubricated. Remember, the exhaust valve is basically horizontal and gravity is not helping. Between the cam cover and the oil cooler, the engine traps about 1-2qts of dirty oil at all times. That's why I always suggest multiple oil changes to flush the system. |
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Mark Rosenbaum Member 
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Judson Manning wrote: Leave the epoxy in place. That was a 'fix' done to the early castings, later castings (mkIII aka JH5) are all solid. The design was later revised with the introduction of the 910. Did Lotus change the casting revision code when they added the metal web, or did they just do some Fine English FettlingTM on the dies? |
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smcmanus Member
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Exactly what I wanted to know! Thanks Steve |
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Ron Earp Member 
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Judson, I don't remember my head having any epoxy on it, do you? I also don't think that my head is a JH III head? Ron |
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Judson Manning Member
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Ron, The epoxy 'fix' is fairly rare. It can only be found on those left-over castings when they switched over from rope-seal (#2760) to lip-seal blocks. My original (early) MkII engine #3521 had the epoxy. I can only guess all engines after 4030 received the revised (solid journal webbing and blocked oil drain) cam towers. Your engine has the later castings. Don't ask me why I switched your intake tower for an earlier version (can't give away all my secrets!). The real 'fix' is an Accusump to pre-oil the journals prior to start-up. The other thing is to keep the revs up (i.e. +50psi of pressure) to keep enough oil feeding the head. In your case, you'll burn a valve and need a head-job long before your guides will wear due to a lack of lubrication. Judson |
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smcmanus Member
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An update with the notion that some of this information will be usefull to someone at some point in the future. The engine is all back together and the clearances are all spot on. This was the longest valve adjustment in history. It took over a month. It would have taken a day if I had a shim assortment. Even after getting the shims, I had to fine tune 3 of them with 400 grit emery paper to get them down about 1 thousandth. I think I had it together and apart 5 times. BTW, The shims were $2.25ea at Delta. I was very confused about the cam housing gaskets. The Delta guy said I should use them, but the manual and all advice was not to. I elected to eliminate the gaskets. I was unable to find Loctite 504. Eventually I settled on Loctite 518 as recommended by Lotus. I read the instructions and step 2 involve spraying one surface with Loctite clean n prime activator. I asked my jobber about it and he gave me a blank stare. I called the Loctite hotline (1-800-LOCTITE) and talked to an expert. I learned more in that phone conversation about sealants than I will ever need to know. The guy was very helpful and told me that the clean n prime activator wasn't needed unless sealing plated or anodized surfaces. Thanks Steve |
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