Lotus Twin Cam .120" oil orifice...pinging Rod;

[thruthefence]

Examination of the illustrations in the David Bean catalog shows an oil restrictor, #1710 with an orifice of 0.120".

A friend of mine over on the Europa board, is having low oil pressure problems on a fresh Twin Cam overhaul, clutching at straws now; but is anyone familiar with the placement of the orifice, and the likelihood of it's being overlooked during an overhaul? "overlooked" means "left out" of the casting. I would assume it would be removed for cleaning the oil galleries?

 

[patprimmer]

Rod

Being an experienced air cooled VW boxer engine guy, I can absolutely verify that over boreing the main bearing bores in the crankcase is std operating procedure on the VWs when overhauling as the bearing shells inevitably pound into the aluminium or magnesium crankcase and lose bearing crush.

Regards
Pat
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[evelrod]

Yes, Pat. I know about the bug engines although I prefer the wobbled out mag cases as 'campfire fuel'. What I meant was overbored engines from the OEM and not from a rebuild scenario.
Of course, at the time I learned about it (the hard way, of course), in my 'group', "VW" was used in the pejorative mostly. I love ya, babe...I'm just not a bug person! ;-)

Rod

 

[patprimmer]

No problems Rod.You love em or hate em, mostly for the same reasons. They served me well, but then again I mostly barrack for the underdog and loved the ummm shall we call it the surprise effect when the old beat up Beetle pulled into the overtaking lane up a steep mountain road and blasted past a big V8 already doing his best.

Regards
Pat
See FAQ731-376 for tips on use of eng-tips by professional engineers &

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for site rules

 

[thruthefence]

First off, thanks to all for the help & suggestions.

Here's the cut'n'paste from the long suffering Lotus Europa Twin Cam operator:

"I finally got the engine installed, and on start-up, the oil pressure is
60PSI. The problem was that the oil pickup tube was too close to the bottom
of the pan, which "strangled" the oil pump. I cut off 3/8" and now I have
great oil pressure."

Apparently someone suggested a wad of modeling clay under the oil pick up screen when dry fitting the pan, and then measuring the clearance!

"All's well that ends well"

 

[thruthefence]

A follow up to my previous post, by another interested party:

I'm curious, and you may have already told us this way back somewhere .

#1 Is this engine based on a 711m or 771m "tall" block ?

#2 would it be "does it have a Lotus or Kent/Cortina pan on it ?"

I fear light is dawning on Marble head over here ...

 

[evelrod]

Early twincams had pans with rope seals. Four bolt flywheel flange on the crank, small main caps and, thread in oil pickup. 105E and truck "L" blocks were common. Later engines used a variant of the Kent with a pressed in pickup, big maincaps, neoprene rear seal with a six bolt crank flange. Both are "low" blocks in stock form. It is, however, quite easy to use the 116E block, the Kent Cortina/Pinto 1600 block for a big displacement twincam...any where from 1700 to 1900 with almost no real added expense aside a decent forged or billet crank and a good set of Carillo/Cosworth/whatever connecting rods (I use a set of L18 Nissan rods). I don't cut the block but rather make a spacer for the front cover, a couple added links in the timing chain and a relocated chain tensioner. You cannot tell the difference with a bit of camouflage paint...)

For intent and purpose, save the rear seal, both pans are identical.

Rod