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Lotus Twincam Engine Modifications

PostPosted: Tue Feb 21, 2023 7:09 am
by rgh0
Since i retired from full time work recently I have had time to start documenting some of the information I have collected over the years on modifying Lotus Twincam engines.

I have attached the first 5 chapters in a series of PDF files that I have broken down to keep within the 2MB limit for individual files on the forum. These focus mainly on history from the earliest protoypes up until the current day with information on the various engines built and how they differed. The head section in chapter 2 is an expansion and update of a document I wrote and posted a number of years ago. Most of this infromation is avaiable somewhere if you search hard enough but putting it in one place makes it much easier to find and understand and to cross check for inconsistencies and errors in the previously published scattered infomation


The chapters 6-10, that i am still working on, will focus in more detail on how to build a modified engine today for the best results. i am aiming to finish these chapters in the next couple of months

Many thanks to Tim Wilkes and others on the forum who have provide detail data and photos. i am sure i have made many errors and omissions and I would welcome any comments on corrections or areas which could have had more information added.

cheers
Rohan

Chapter 1 Lotus Twincam Modifications.pdf
(567.27 KiB) Downloaded 725 times


Chapter 2 Part 1 Lotus Twincam Modifications.pdf
(1.77 MiB) Downloaded 608 times


Chapter 2 Part 2 Lotus Twincam Modifications.pdf
(885.12 KiB) Downloaded 505 times


Chapter 3 Part 1 Lotus Twincam Modifications.pdf
(1.5 MiB) Downloaded 502 times


Chapter 3 Part 2 Lotus Twincam Modifications.pdf
(1.14 MiB) Downloaded 477 times


Chapter 3 Part 3 Lotus Twincam Modifications.pdf
(1.56 MiB) Downloaded 491 times


Chapter 4 & 5 Lotus Twincam Modifications.pdf
(1.16 MiB) Downloaded 580 times

Re: Lotus Twincam Engine Modifications

PostPosted: Tue Feb 21, 2023 8:12 am
by gherlt
Hello Rohan,
great work !
I can offer hosting space for the entire pdf, with a download link in the service area of https://theelanman.com/

regards
Guillermo

Re: Lotus Twincam Engine Modifications

PostPosted: Tue Feb 21, 2023 8:49 am
by Andy8421
Rohan,

This is great stuff. Its a labour of love to produce a report like this, and a great deal of work. It looks to be excellent quality.

Your timing is perfect, I have finally started to strip my engine to discover all sorts of horrors inside. I had planned to bother you from time to time for advice, but if you get chapters 6-10 completed, then you can have your semi retirement in peace without emails from me.

Thanks for all the effort.

Andy.

Re: Lotus Twincam Engine Modifications

PostPosted: Tue Feb 21, 2023 9:07 am
by rgh0
Hi Andy - feel free to contact me with specific questions. The later chapters while addressing many specific issues of engine mods will not address them all I am afraid. Also specific questions help me know what I need to write to help people :D

cheers
Rohan

Re: Lotus Twincam Engine Modifications

PostPosted: Tue Feb 21, 2023 9:18 am
by 2cams70
I see my “Truck engine” quote gets a mention Rohan!!!

Re: Lotus Twincam Engine Modifications

PostPosted: Tue Feb 21, 2023 9:21 am
by vstibbard
You really are a legend Rohan. I’m looking forward to reading this and will eagerly await future instalments.
Cheers
Vaughan

Re: Lotus Twincam Engine Modifications

PostPosted: Tue Feb 21, 2023 9:36 am
by rgh0
2cams70 wrote:I see my “Truck engine” quote gets a mention Rohan!!!



Ha Ha Ha

cheers
Rohan

Re: Lotus Twincam Engine Modifications

PostPosted: Tue Feb 21, 2023 9:51 am
by rgh0
gherlt wrote:Hello Rohan,
great work !
I can offer hosting space for the entire pdf, with a download link in the service area of https://theelanman.com/

regards
Guillermo


Hi Guillermo

Thanks for the offer and i will take you up when I complete the full document. In this internet age you ensure long term survival by having multiple hosting sites and using a file format such a PDF which is unlikely to be obsoleted in the next 50 years and if it is, there will be some upgrade translation available.

cheers
Rohan

Re: Lotus Twincam Engine Modifications

PostPosted: Tue Feb 21, 2023 10:00 am
by HCA
Like it Rohan! Excellent, and without unnecessary waffle!

A pity that Oz is, as you say, so far away - I would have let you have my John Wilcox (but I am sure it is Tony Ingrams as well...) SAS ported head with the 33mm inlets for your evaluation on its design.

I have not yet digested your chapters on blocks yet, but do keep them coming in!

Re: Lotus Twincam Engine Modifications

PostPosted: Tue Feb 21, 2023 10:29 am
by trw99
Well done, Rohan, good stuff!

Tim

Re: Lotus Twincam Engine Modifications

PostPosted: Tue Feb 21, 2023 4:42 pm
by UAB807F
Another "well done" Rohan, this is an incredibly generous undertaking. I'll be honest, I'm not about to rip my engine apart (I only tend to do that when something's worn out) but I do like reading about what others are doing.

Aside from the offers of hosting, if you have a gmail account you will also have access to a gmail drive to store up to 15gb (?) of data for free.

If you set up a folder to store the complete work there you can easily give others read-only access via a link. That's what we do for my missus & her Women's Institute branch and I've done the same for some Lotus Europa data.

Once again, thanks for taking the time & trouble to post this.

cheers
Brian

Re: Lotus Twincam Engine Modifications

PostPosted: Tue Feb 21, 2023 9:05 pm
by ill_will
Thanks Rohan! An amazing resource.

Looking forward to having a read through.

Will

Re: Lotus Twincam Engine Modifications

PostPosted: Tue Feb 21, 2023 10:00 pm
by h20hamelan
Timely

01EB0829-D691-474B-9B6A-6B20527EEEDC.jpeg and



Thank You Rohan

Re: Lotus Twincam Engine Modifications

PostPosted: Wed Feb 22, 2023 11:50 am
by AshleyPark
Yes, great stuff Rohan!

I've recently finished rebuilding my Sprint engine and I have to say how helpful I found your thread "Removal and Rebuilding of a Twincam" was. Thank you.

Re: Lotus Twincam Engine Modifications

PostPosted: Wed Feb 22, 2023 4:06 pm
by 661
Thank you for posting these