Lotus Elan

How to build an oil tight twincam?

PostPost by: h20hamelan » Sat Oct 02, 2021 2:33 am

2cams70 wrote:Here.


viewtopic.php?f=39&t=47993

So thanks 2cams70, good one. 12th post in link
Born, and brought home from the hospital (no seat belt (wtf)) in a baby!
Find out where the limits are, and start from there
Love your Mother
Earth
User avatar
h20hamelan
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1223
Joined: 25 Sep 2010
Location: RACECAR spelled backward, is——RACECAR!

PostPost by: marode » Sun Oct 03, 2021 9:34 am

You can use the rubber sump seal at the rear IF you change the rear seal carrier to the later design,


Brain, are you referring to this part?
https://www.burtonpower.com/rear-oil-se ... fp306.html

Do you think it’s worth converting to the rubber seal?
User avatar
marode
Second Gear
Second Gear
 
Posts: 50
Joined: 04 Aug 2010
Location: Kassel, Germany

PostPost by: marode » Sun Oct 03, 2021 12:43 pm

alan.barker wrote:What is the Clearance on the Valve Guides.


Now I know: inlet is 0.04 to 0.05mm (in spec but a bit towards the maximum), Whereas exhaust is 0.03 to 0.05 which is s bit too narrow (should be 0.06 to 0.075).
User avatar
marode
Second Gear
Second Gear
 
Posts: 50
Joined: 04 Aug 2010
Location: Kassel, Germany

PostPost by: ncm » Sun Oct 03, 2021 8:16 pm

That's the part.
Is it worth changing your current cover? Probably not as you still have to use the cork seal at the front so will be unable to use the Cometic gaskets that are cut too short. :( :(
Brian.
ncm
Second Gear
Second Gear
 
Posts: 187
Joined: 02 Jun 2006
Location: Derbyshire

PostPost by: 2cams70 » Sun Oct 03, 2021 10:23 pm

ncm wrote:You can use the rubber sump seal at the rear IF you change the rear seal carrier to the later design, however you cannot fit the rubber front seal as the groove in the timing case is narrower on the twincam (the same as early crossflow and the precrossflow ) than it is on the later 711M engines.To claim that this :-https://www.burtonpower.com/cometic-lotus-twin-cam-timing-case-gasket-set-c4491.html fits the twincam really is out of order as the sump gaskets in this kit are for the 711M style engine and will not work with the cork seals as shown in your picture.

Brian.


Possibly. You can only successfully use the later design rear carrier if the raised lip inside the sump recess where the carrier fits is in the same position as the later sumps (1973 onwards) intended to be used with this carrier. It's not something I've checked personally. As another poster said - the timing cover is always going to be cork anyway. Trying to convert is not something I've ever bothered with. The Nitrile rubber seals will harden and lose compression over time just like cork does.
1970 Ford Escort Twin Cam
1972 Ford Escort GT1600 Twin Cam
1980 Ford Escort 2.0 Ghia
Peugeot 505 GTI Wagons (5spdx1) (Autox1)
2015 Honda City 5spd.
2cams70
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1279
Joined: 10 Jun 2015
Location: Australia

PostPost by: Hawksfield » Mon Oct 04, 2021 11:48 am

Hi 2cams70

That's something new in all the discussions around TC sump seals, that the sumps are different between post1973 and pre 1973 TC six bolt sump pans, that's something to be aware of

Thanks for your input

I once used a rubber halfmoon from a xflow gasket set and the rear seal distorted and finally leaked that accounts for it. :!:
John

+2s130 1971
User avatar
Hawksfield
Third Gear
Third Gear
 
Posts: 445
Joined: 14 Jul 2004
Location: Hartlepool Teesside

PostPost by: rgh0 » Tue Oct 05, 2021 8:33 am

Hawksfield wrote:Hi 2cams70

That's something new in all the discussions around TC sump seals, that the sumps are different between post1973 and pre 1973 TC six bolt sump pans, that's something to be aware of

Thanks for your input

I once used a rubber halfmoon from a xflow gasket set and the rear seal distorted and finally leaked that accounts for it. :!:



The Lotus Twink 6 bolt sumps twin cam up to the end twin cam production of did not change and always match the narrower cork rear seal and carrier as far as I am aware, but whether the later post 73 Ford sumps were changed to match the wider rubber seal I dont know but by then I think they were not making front bowl sumps for Kent block engines except for Lotus ?

cheers
Rohan
User avatar
rgh0
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 8019
Joined: 22 Sep 2003
Location: Melbourne, Australia
Previous

Total Online:

Users browsing this forum: No registered users and 23 guests