'74 TVR 2500M

I'm planning on getting the Mikuni set-up from Vintage Performance Developments. They have adapters already set up, but I think that they can probably be improved upon with a little manifold work.  I intend to use the car in autocross (SCCA Heritage Classic Street) where I am currently using my TR3. I probably could have used the GP2 cam, but Sam and Richard Good assured me that with the other mods I will not see much loss down low but really enjoy the rush at the upper rpm range!  I hope he's right... I won't be above 5k all that often.  Sam has an engine stand for test runs, but no dyno in his shop. My distributor was set up by Advanced Distributors based on my build specs.

We had the Goodparts GP3 cam in the autocross car in Virginia, and it certainly didn't suffer down low.  At higher RPMs, it would pull hard right up until the rev limiter kicked in at 6200.  I would highly recommend having some sort of rev limiter on this setup.

It's looking really good.

In reply to JoeTR6 :

I seem to recall your having mentioned the rev limiter before, Joe. Sounds like the voice of experience... I will heed your advice! Thanks. 

In reply to JoeTR6 :

Joe, I'm going to send you a PM about the rev limiter. Definitely something I'm interested in for my car as well. 

In reply to oppositelocksmith :

Keep me in the loop!

I should say it was drop dead simple with a Megasquirt.  Carburators complicate it quite a lot.  There are electronic ignitions (e.g., MSD) that can feather spark but the fuel will keep pouring in.  I think the trick would be to use a soft limiter that doesn't completely cut spark but cuts random cylinders to keep the fuel burning but limit power.

Thinking about this some more, the TR6 in Virginia originally had an Electromotive HPV-1 ignition that did this with triple Webers.  Worked great.

Stu Lasswell said:

I'm planning on getting the Mikuni set-up from Vintage Performance Developments. They have adapters already set up, but I think that they can probably be improved upon with a little manifold work...

Interesting website, they have some cool stuff. My '98 Ducati has Mikunis. Different style but I'm happy with how they run. I wonder, did you happen to notice that site's Google reviews? There's only 3 but they're all 1 star.

   Darn!  I may not be going with Mikunis after all. I just looked into some of the comments on MG and Volvo sites, and there seems to be a general dissatisfaction with John Parker and his company (VPD).  Since I'm now up to 5 Zenith-Strombergs I might as well get a couple of them rebuilt and see how it goes. If I need more carb than that, I can still  get Rich Good's tri-carb manifold and add another one!  I'd rebuild them myself if I knew them better, but I know a guy locally with a good reputation who will do it. Maybe I can get him to go through them with me so I can familiarize myself  with them.

Stampie said:

Just wanted to throw out my recommendation for National Carbs.  They're local to me and do a great job either stock or custom.

https://nationalcarburetors.com/

Just saying ...

In reply to Stampie :

Check their site, Stampie.  Try looking for Triumph, MG, Austin Healey, TVR... anything that used S.U. or Zenith-Stromberg carbs.  It's like those makes or carbs don't exist!  They're probably great for the more common/popular models, but I think I'll stick with someone familiar with these specific carbs! But hey, I do appreciate your suggestion!

I have four extra Strombergs that you are welcome to.  They aren't generally hard to rebuild except for the throttle shafts, and for that I sent mine to Joe Curto.  If you need extra tunability, they can be fit with adjustable jets.  I also know where there may be a set of used triple Webers if you care to go that route.

Throttle shafts on a ZS are easy! :).

One interesting option you could consider is the new fuel injection setup by Ramin Mirshab. He’s active on a bunch of the FB sites and had some running cars at the VTR Nationals this past week. I’ve spent a bunch of time talking with him about it, and it looks like good kit. I almost put it on my car...

In reply to Stu Lasswell :

That's cool.  I think their list is the rebuilds they keep in stock.  Of course they would only stock the more common/popular models.  They do offer to rebuild others that aren't on the list.

In reply to oppositelocksmith :

Interesting. I've been avoiding even looking at fuel injection (like Patton's) figuring I'd stay with the relative simplicity (of set-up, anyway) of carbs. May be it's time I consider moving into the 21st century!

In reply to Stampie :

Again, thanks, Stampie.  There are plenty of people who specialize in British carbs, and I think I would be better served by them, especially if I can get the work done locally, or close.

In reply to JoeTR6 :

Thanks, Joe,  Again, I have FIVE 175CD carbs already... I may just see that as a sign to accept the inevitable, and learn to love them  (or at least live with them)!

Stu Lasswell said:

In reply to JoeTR6 :

Thanks, Joe,  Again, I have FIVE 175CD carbs already... I may just see that as a sign to accept the inevitable, and learn to love them  (or at least live with them)!

Oh, you didn't want one per cylinder (ducks).

Well, things have been progressing, if at a snail's pace.  As I noted before, the engine/trans. unit is in place. I borrowed an angle gauge (thanks, Michael dusterdb13) and made sure that my working angles for the drive shaft were within spec. No issues there... in fact, I was able to add back in some of the spacer blocks we cut out, giving me more clearance over that pesky frame member! Here's a shot of the chassis with the now-complete drive line, and a shot showing how much clearance I have at the differential flange.

Today I also got the new high-torque starter installed.  As I believe I intimated previously, I have decided to stick with the Zenith-Stromberg carbs.  I found a local club member (and Vintage Triumph Register president), Jack McGahey, who will rebuild some of the carbs I have. Now, since I'm not buying new Mikuni carbs and have five Z-S carbs laying around,  I figured I'd spring for the GoodParts triple carb set-up.  I mean, if two are good, three could only be better!  Jack has volunteered to work with me and "learn me" Strombergs so we can properly install and set them up!  I guess I'm pretty much caught up on the mechanical part of this build (well, the major parts) so I'll have to start really looking at the bodywork next!

Sounds good, Stu!  Nice progress!

Triple carbs!!!!!!

That makes me excited. 

Glad the driveline angles are solid.

Jack is definitely another guy who knows his stuff!

Nice progress! 

A little unsolicited advice. Sell the 5 Strombergs. Buy 3 SUs and one of Richard’s triple carb manifold kits. Stop worrying about it. 

Not to be biased... which I am but EFI is the way to go. Why?

-Self tuning, it automatically adjusts to any weather, elevation and future engine modifications/changes.

-The parts are readily available. My kit uses all standard GM sensors that routinely last 100-150k miles and are found at any auto parts store in the country. BTW it can run on just 1 sensor so if the others die (highly unlikely) you'll still be ok!

-Near perfect fueling. As stated above its self tuning! It will reach whatever AFR you command and hold whatever idle speed you tell it to

-Its not too expensive. For around $2200 you get a setup that is trouble free, has way better throttle response, gives you data (if you wish) and does not require routine rebuilds. As the car's age less and less reliable carburetor kits and rebuilders will exist.

-Webers are a nightmare and much more expensive. Their base price is just that.. a base. You still need hours of tuning, jets, chokes, emulsion tubes, filters, fuel pumps etc. Then once the weather changes you are back to square one. 

Is it complicated?

No! simply bolt on the manifold, install the high pressure pump and match the colorcoded, labeled and numbered wires to the sensors. Turn the key and drive!

Performance Increase?

-Recently a race team in Texas fitted this to their TR6 and saw a 4 second reduction in lap time. 

Sorry to turn it into an advertisement but my interests aren't to make money, this is a side business. What I enjoy is seeing something I make bring positive benefit and joy to those that use it.

“I will say, I’m completely sold on fuel injection now. I’ve driven plenty of Triumphs with all kinds of carbs, nothing compares to this" - Greg B. Texas

Pictures

https://imgur.com/a/Zq2SWBs

   This last weekend my wife and I went down to Savannah GA, and I talked her into hitting the Charleston (NC) British Car show on Saturday.  I hoped to see a few TVRs, but alas there was only one in attendance, and it was a bright yellow "wedge". Talking to the owner, he mentioned that he had previously owned a TVR 2500M, fitted it with a Toyota 4AGE, and that his son in Chicago had it now. Small world!  I told him how we had been in contact with his son (Adam Cohen) via our grm group, and had talked to the guy he had previously sold it to (Jack Ingold) as well.  Although I'm not really a fan of the "wedges" his was one of the rare Rover V-8 powered ones... what's not to like!

In reply to Stu Lasswell :

That's pretty cool, Stu! 

I'm not a big fan of the wedges either, though there's one (theoretically) for sale on the TVRCCNA site that's a coupe.  Looks a lot cleaner than the drop-top versions.