How to approach an overhaul

[leeper]

Wow! That gives me a lot to chew on and figure out before pulling out the sawzall. J/K, I don't need to instigate, I want to put together a solid plan before I start anything!

 

It might just be that the early posts were right in that I should have bought an ultralight but your comment about a Donkervoort with an S2K was in my head from the first time I saw it. If I can work out the problems on paper first, it is something that I would love to do but I'm a realist as well.

 

Your point #9 has been nagging at me and you make an excellent point about why if the car won't be put on the track. I'm looking into alternatives solutions and have a couple great local mechanics looking at it as well.

 

Can't thank you enough for the post, wish I lived a bit closer to see/hear your work! Someone else clarified for me the difference between what Brian provided for you vs. where you have taken the cars to now and I have a much better understanding!

 

Thanks again,

Calvin

[TheDingo8MyBaby]

One thing I notice is you seem to make a lot of assumptions that parts for these cars won't be available much longer. There are SEVERAL places that carry these parts and several that are developing new and better parts (read davebean.com). There are so many vintage lotus/fords still around that there should be parts for years to come (so long as we still have gas to use them).

 

The Twincam kent is a wonderful motor. Brilliant sound and a great racing pedigree. Have you considered taking your twincam and building it to be absolutely bullet proof? Forged pistons, billet crank, electronic ignition, removable water pump, etc? You can get 180HP+ reliably if you do it right. Rebuild the brakes, pull the tranny and have it rebuilt - if it's a 4 speed, it shouldn't be too much work to upgrade to a t9 5 speed (I'd reccomdend a close ratio). Rebuild the rear end and throw a limited slip in. Unless it needs electrical work, I don't see much else that would make the car unreliable.

 

The reason you are having speedo trouble is the speedo quill for your gearbox is much too weak and breaks too easily. Simple solution is to machine one out of steel and you shouldn't have a problem any more. Only problem with doing this is it may snap the cable eventually instead. As long as you keep it lubed and don't run it at any awkward angle - it should be fine. A new cable isn't that expensive anyway.

[leeper]

Davebean.com was the original importer (and builder) of this car some 27 years ago. Approximately 7 years ago he provided most of the parts behind the rebuilding of the engine. You are right about the assumptions, but it isn't rocket science - 37 year old engine, 42 year old drive train. Can I still find parts? Yes but why make things harder on yourself than you need to? Why would someone today use those parts? To restore it to original. But this is a kit car. It’s not like Colin Chapman ever touched this car, other than in theory and it's pretty hard to believe that that he would go this route based on what his history was. Joop is still making cars but they are rather bloated and definitely not the direction that I want to go.

It’s hard to dispute the sound that the engine makes, that is for certain! I actually had thought long and hard about the changes that you are referring to (and it’s still not off the table) but when you look at it all and the destination is 180, then compare that to a starting point of 240, you start to question the logic. HP gains are not the goal, just used them to illustrate the point.

 

An argument can be made for either side quite easily. I have been on the "other" side of the debate so far and will admit to being bias towards the S2K. Is there anyone here who can point me towards a solution that is much closer to the Cortina drive train? I've heard of several comparable engines (Ford - Kent/Lotus/Cosworth/Duratec) but nothing on the drive train.

 

3. Engine size will most likely warrant chassis changes especially where the dash bars go to the tranny. This is most likely to narrow for the six speed to fit.

You might can use existing tranny and just change engine but this will require custom adapter plate and clutch. Tranny may not hold power.

 

One look at the tunnel compared to the pics that I have seen of Ultralites tells me that mine is considerably smaller than that of an S2K. Even if I expanded the tunnel to adapt, where the hell would my arse go? There is a bit of padding to give up but diets are out of the question. Anyone know of any Ultralites out this way? I would love to sit them side by side.

 

The speedo was a misunderstanding on my part. Jeff (previous owner) re-explained it to me and it is the elbow that needs to be replaced as opposed to the speedo itself (apprx $200-$300) and it can be purchased “new” at Davebean. I will look into the quill though.

 

Cheers,

Calvin

[DeanD3W]

Since I think your car has the best looking nose and hood that I've ever seen on a sevenesque car I think it would be good to leave it untouched... I think the Honda F20 is too tall, even with a dry sump, and as you and others have mentioned, the transmission is large too.

 

A Duratec might fit better, but it has right side exhaust, so to meet your objectives in the cleanest way it seems like a Ford Zetec, with its left side exhaust and right side intake, would be a good choice..? Probably with a dry sump to avoid the too common, too low oil pan in these cars.

 

Dean

[TheDingo8MyBaby]

The speedo was a misunderstanding on my part. Jeff (previous owner) re-explained it to me and it is the elbow that needs to be replaced as opposed to the speedo itself (apprx $200-$300) and it can be purchased “new” at Davebean. I will look into the quill though.

 

The elbow is actually what is called a right angle drive. 95% of the time, the right angle drive is fine and it's the $3 quill inside the right angle drive that has broken.

[11Budlite]

Calvin,

 

First off, let me say that you have a beautiful car and I think you should try to keep as much of the present look as possible!

 

If you do want to change out the drivetrain there was a good discussion of the different concerns of installing an S2000 drivetrain in a standard size se7en. Here's the link: http://www.usa7s.com/vb/showthread.php?t=4125 Also check out the link to Jack P's (Birkin42) build of an S2000 eng/tranny/IRS (actually a DeDion) in a Birkin. He's doing a very nice job and should give you an idea of what's involved. Here's his link (I'm at work so I can't verify that it works): http://www.flickr.com/photos/10827861@N07/page4/

 

I would agree with Dean that the easiest modern update with little mods to the existing hardware would be a Zetec (with a T9 to add a 5th gear). This has been done to most of the Birkins/Caterhams over the last decade or so.

[Birkin42]

An S2k will fit in a traditional size 7 if you try really hard, are prepaired for a few sacrifices, and are up for a lot of work. It is no where near close to a drop in even with a few mod's. I needed to completely rework the frame from front of the engine to back of the trany tunnel. This will also require complete rework of the panels for the tunnel.

The engine is shifted to the passenger side by 3/8". The S2k trany is fat on the passenger side so this also narrows the passenger footwell. I also shorted the passenger footwell for space for the dry sump tank.

The engine now almost fits under the stock Birkin hood. The last thing that I need to a dress this is cut away a small portion of the valve cover at the front.

I had my reasons for wanting to go the S2k route. I think I will be happy once it's done, but it is a lot of work. It's probably not too much less work than building a car from scratch.

For me, designing and building is a big part of what I wanted out of building this car, but if you are not a builder and just want to make the change for the final result, I'd recommend buying something like a WCM that gets you there to start with.

 

I haven't had time to work on the car much laterly due to work, but hopefully this fall I will be back into it and can post some updates as progress is made.

[Arya Ebrahimi]

The best way to approach an overhaul is to sneak up on the car quietly with sawzall in hand

 

Seriously though, after significantly "reconstructing" a 7 to fit a new drivetrain(Olds small block to LS1), I think we(Mazda and I) would have been ahead by starting from scratch and using the existing car for simple dimensional references.

 

The Rotus we started with was not exactly a gem in terms of fit, finish, and overall condition, so there was little remorse in cutting it up. With a car that appears as clean as yours, I would do my best to avoid major reconstructive surgery. It may sound like a broken record, but there are better platforms for what you propose.

 

Just my $.02

[leeper]

Yes I've come the same conclusion. I'm going to work on the engine (the Twincam) and have a bit of fun but I'm going to do nothing that changes the exterior. If you can't tell I'm a bit hesitant to elaborate :ack:.

 

At the same time I'm keeping an eye open for a '91- '96 SEiGHT with the intent of completely dismantling/rebuilding. It will take me a year to talk the better half into letting me have a second toy of this scope but if you hear of one, please let me know!

 

Thanks for everyones input.

 

Calvin

[Croc]

Hi Leeper

 

Now hopefully I do not reopen a can of worms here....but I found another post with good pics this morning on the WSCC site in the tech forum which probably validates the way forward that you describe above. It is a s2000 with type 9/quaife going into a Westfield with the regular bonnet (not the seight bonnet).

 

http://boardroom.wscc.co.uk/cgi-bin/ikonboard.cgi?act=ST;f=3;t=82482

 

I love the engineering that has gone into this, the dry sump looks particularly nice, however the ground clearance would be fatal for a car intended to be driven on the road.

 

Having followed this thread with interest, I thought this would be a useful data point in the consideration.

 

Cheers

[leeper]

Thanks but this is definitely a road car and I agree with both points (sump and ground clearance). I decided to go a different route and thought I should start a different thread.

 

Cheers