TR4/4A TR3/TR4 Weber DCOE serious fitment issues

[richie]

Hi everyone,

I was excited a little while ago when I found and purchased a twin Weber DCOE 40 kit to replace my tired leaky Strombergs. The kit was purchased directly from Pierce Manifolds who took over design of TWM manifolds, and who is a massively large Weber distributor / tuner extraordinaire.

I got my car out of storage to find that the inlet manifolds were significantly interfering with the stock cast iron manifold. I first thought it was my header wrap, so I removed the wrapping, only to find it still wouldn't fit by a long shot due to clearance issues on the inside two cylinders. Here are a few examples of fitment issues with the inner runners:



So, my thinking is, I got Webers, maybe I need to buy a header as a sort of "price of admission". Turns out, very few people seem to be able to assure me their headers will be compatible with the oversized TWM inlet manifolds. I've tried BP Northwest, Rimmer Bros, TSI etc... And whats more surprising is that the manifolds don't even have enough clearance for the factory clamps which clamp on both the inlet/exhaust manifolds, the solution is to use hex/allen bolts with large washers which in my opinion wouldn't feel adequate:



I have only found one thread so far which indicated that the only inlet manifolds known to be compatible with the stock exhaust manifold is the CANNON manifolds. Fellow user Darrell_Walker posted a thread about his findings and seems to conclude that the TWM kit, as sold by Moss/Pierce, MAY fit with the Moss header.

At this point I am sharing this to share my experience with others, and hopefully, to find someone out there who might have some advice on how to successfully get these modern 'TWM' manifolds fitted on a TR3/TR4. I'm really having a hard time shelling another $500 for a header which will still have clearance issues with the Cyl #1 tubing.

Any wisdom or experience would be welcome, if not, maybe this thread will be a warning of the "fitment" of the TWM kits...

 

[TR3driver]

I've no experience, but ISTR others saying they got them to fit with judicious grinding of all components involved (both manifolds and the clamps).

 

[PeterK]

What advice did Pierce have? Did you ask them since they sold you the manifolds? I'd always start there first.

 

[M_Pied_Lourd]

Not any help sorry, but just wanted to confirm as mentioned that the Cannon manifolds work with the Moss SS header. I did have to add a little weld to build up the contact area on the header where the football clamps held it but that's all the mods that were required.

Just a quick video of them installed...

https://youtu.be/_7QUGJqyCKw

Cheers
Tush

 

[richie]

What advice did Pierce have? Did you ask them since they sold you the manifolds? I'd always start there first.

Pierce has been as helpful as they can be, their tech shop was telling me that they don't really sell very often to customers, more to shops/distributors like Moss etc, so they haven't had much first hand knowledge/experience of fitment issues. I've gotten the majority of my answers from Moss but we still can't seem to come to any solid conclusions.

At this point the more I think about it, there's no real solution besides buying another header and dealing with whatever final fitment issues there are with the header. I might need to seek reimbursement and go with Cannon's or go with another carb option.

 

[richie]

Not any help sorry, but just wanted to confirm as mentioned that the Cannon manifolds work with the Moss SS header. I did have to add a little weld to build up the contact area on the header where the football clamps held it but that's all the mods that were required.

Just a quick video of them installed...

https://youtu.be/_7QUGJqyCKw

Cheers
Tush

I've watched your videos a few times actually! Did you every try fitting them with the stock manifolds by any chance?

 

[M_Pied_Lourd]

Hi Richie,

No, I never did try with the stock exhaust manifold...sorry.

Cheers
Tush

 

[richie]

Hey all, just wanted to log it for the history books. I ended up returning the kit as it looks like the only way this will work is if I order a header from Moss (they are not producing any at the moment due to their own fitment issues), or something else (TSI has a 4 week lead time and no confirmed fitment, BP Northwest has no confirmation of fitment either). Other option was to go with the Cannon linkage/manifold kit but that's just getting way too pricey. So unfortunately, no Webers for me in the near future. Contemplating SU's or Mikunis. Thanks to everyone for your insight.

 

[scb10s]

I have just finished installing a pair of Weber 40dcoe carburetors and TWM intake manifolds to my 67 TR4a. I did all my grinding on the intake manifold and clamps (football shaped ones) , no metal removed on the stock exhaust manifold. I was actually able to get the accelerator linkage, that was provided to work but, it wasn't all straight forward. I hooked my one man brake bleed vacuum pump up to the distributor so I could simulate manifold vacuum conditions; the PCV valve is not connected and this is where I'm looking for feedback from others. The new ( over ten years in the box) TWM manifold has no porting for PCV or distributor vacuum advance. I would like some coaching on what others have done to employee these two items into the overall engine system. The documentation on the Webers (40 DCOE 151) does not identify a vacuum tap for the distributor (still have the original one installed) and It has been converted to electronic ignition and I have no complaints with its performance. The engine runs very well as it should with nearly all new parts internally. Appreciate your feedback/guidance.
Stan

 

[Hamish Racing]

I and others just don’t bother with the dizzy vac.
i went to a formatted 43d dizzy without vac for my set up with DCOE 45

 

[mctriumph]

Just a side note, but the Jag 2 inch carbs will bolt-up to a Tr3 manifold netting you just as poor fuel economy
as the jag had.....I have seen weber conversions that got terrible fuel economy too .No doubt due to lack of tuning
on the DIY owner. Guess anything can be done wrong...
Mad dog

 

[davidzeeso]

Stan - 1960 TR-3A, installing as you did, file and grind on manifolds complete. ?How to insert black plastic sleeves for linkage rod?
Did you solve vacuum advance connection problem? I had anticipated reusing air filter arrangement I had on Weber down drafts,
but read that the air horns are essential for DCOEs. How did you fit air filter(s)?
David Z

 

[Jim_Stevens]

Short horns and ITG foam filters.