How not to build a Twin Cam engine!

Interesting video of repairs to a severely damaged twin cam cylinder head and also dismantling of another head which has been very poorly built by a previous, unnamed workshop.
Do these belong to anyone on here?

youtu.be/JMhbjhYxNtM?si=y5gQ2noHXCkS8fmV

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I have seen shoddy work similar to this before , from a Dagenham based tuning company!
No prizes for guessing which !

Hope it is not something that has my name attached to it. Not looked at the video yet :laughing:

Leslie

Phew, thats a relief, not one of mine :smiley:

That could not possibly have been built by a professional workshop. It must have been built by a home builder…surely. Double shims…two for the price of one :laughing:

Video was filmed on 1st April.

L

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The poorly built head was clearly to soft and is beyond repair. Whoever built it has no idea of what to do

cheers
Rohan

He needs the blue gloves. Harder to put on but sturdier.

Stem seals? He doesn’t seem to know that they’re not originally fitted to a Twink.

I think he does … he
says they are Ford diesel stem seals.

Indeed he did. But given the level of commentry about all the damage done to the head, and the double shims, I would have expected him to say that the seals shouldn’t be there. Instead he implies the wrong ones are fitted.

Anyway… it is a proper bodge up of a head. I wonder if the owner is going to end up paying more for a repair than a replacement…?

Hi Jon,
I agree he could have been clearer but, to be fair to him, he did say they shouldn’t be there. YouTube’s voice to text software obviously struggles with the Dagenham accent but the transcript has this :----
“oh we’re running stem cils don’t run stem cils on the Lotus”

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I must’ve missed that! :smiley:

"The poorly built head was clearly to soft and is beyond repair. Whoever built it has no idea of what to do

cheers
Rohan"

There has long been a “rumour” that a batch of rejected “soft” heads were scrapped by Lotus, but these were then “recycled” by the scrapman & sold to unsuspecting buyers. Perhaps this example was one of these?

Plenty off soft heads from long term use and / or over heating out there

cheers
Rohan

If that work was done by a “professional” then that seems pretty depressing.

I hope whoever’s it is manages to get some of their money back, but agree that s.t. confirmation via a hardness test that head looks like scrap.

Ok

Just watched that video.OMG It’s appalling that someone has done that kind of work,and really needs to be called out for the sake of the people who rely on companies to provide good quality engineering. Even the quy who took it apart( as someone said in earlier post),did not seem to know twincam heads do not have stem seals on the valves and did not mention the head is too soft.

Regards

G

“I won’t say who it was”.
Why not !!??
If I was planning on getting work done in that part of the World, ( which I’m not,), I’d like to know.
Are people scared they’ll be sued, or what ?
If it’s a matter of established fact that the work was done by a particular company, why not tell everyone ?
Then the work might get sent in the direction of those deserving it.
Shouldn’t have to rely on the local grapevine, ( “well, everyone knows” ), etc.

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This post got me thinking that I have never seen a detailed write up of how to assess a Twincam head condition before starting a standard or modified rebuild. So I have decided to write one up based on my experience and add it as a chapter in my book on modifying Lotus Twincam Engines.

I will publish it on the forum when done. Even if you dont do the work yourself it will let you understand what questions to ask a professional workshop you send the head to.

cheers
Rohan

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Poor Little twin Cam heads, they were certainly abuse, but I did notice one had valve stem seals fitted to it has anybody else tried to fit them to their Twin cam

John McCoy of Omni Tech engineering in Bellingham, WA, USA does this regularly. Think it’s a Japanese car engine he borrows them from. Part of the machining work he did on the Weber head from my car.

FWIW, the engine does not burn any oil, after 25K+ miles, including no blue on start up. Has run very well for me (not withstanding the fact I did all the rest of the engine build up myself, and my first twink at that :grimacing: :innocent:)

Thank you, John (and Miles :wink:)

Randy