Triple weber conversion on 1970 Series 2 E-Type

There are many posts on the forum regarding the triple Weber conversion. Let me be up front by stating it’s a done deal, so what I need is some help from those who have done this job. My engine builder included a conversion “kit” when my engine was shipped. Unfortunately he has since moved back to the UK. The Webers and manifold came with no instructions. Most of the install is a no-brainer but there are some questions I need to have answered pertaining to a US Series 2 car. 1). the water/heater hose configuration is different from the odd Series 2 manifold. I have a large outlet from the top of the manifold and think it goes to the upper firewall inlet. However, there is also a LOWER inlet and what goes there? 2). Does the front of the manifold (inlet for thermostat, etc) connect the same? 3) What to do about the vacuum system. I A-S-S-U-M-E that the smaller outlet on the lower rear of the manifold connects to the vacuum tank? How about the crankcase breather up front. On the SU’s it was ported to the SU carbs. Do I just cap it? Since I can’t find instructions anywhere online, and most of the weber photos are on Series 1 cars I’m stumped. Photos please!


The most important thing I would suggest is to ask those on the forum what their Webber settings are.

I had Webers on my car when I bought it. No more said about that!

Wenders have many jets, air correctors and emulsion tubes. With 6 of each to buy when trying to tune, it becomes really expensive.

So if you can get setup data from those who have webers and have been through the tuning of them, you will save a lot of time and money

I wish you success

60 OTS
They sound great!

On the subject of the crankcase breather, do not just cap it or you risk blowing out the front crank seal. You can run a hose towards the ground a la Jaguar 120, run it to a vented catch can, or run a new line to your air cleaner(s).


Thanks Dennis. I have located a Weber tuner in my area that has experience with E-Types. Hope he can get them purring!


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Thank you Steve! Still hoping a few photos show up or maybe a copy of instructions.

I do not know about converting an E to Webers but when I converted my Cosworth Vega to Webers many years ago I attached a hose piece to the breather pipe similar to what Steve suggests and then inserted a small breather filter into my hose piece . I keep it tucked up next to the firewall out of the way underneath my heater box. I un-tucked it for this photo to show my breather filter. Just a thought.

This thread appears to have some Weber jet, etc. numbers to use for the E-type…

68 E-type FHC

Good idea! Works on motorcycles, why not a Jag.

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Hi Bob, I have a Waterford manifold, hopefully yours is similar.
Pics below but:
On the rear of the manifold, the larger outlet does go to the upper firewall inlet. The lower pipe is vacuum on mine and goes to the vacuum reservoir.
Unfortunately, I bought my car with Webers, so I’ve no idea about a stock setup, but the pics show the setup, closest to the block coming from the water pump, then the upper rad hose and the small bypass both go to the rad as normal I would think. The crankcase breather on mine is dumped to atmosphere by a draft tube.

Hope this helps.

Bruce, huge help thank you! Your manifold is similar to mine I think. However, as I looked at photos from my disassembly I noted a water return pipe clamped underneath the original manifold. It has a “T” towards the front where it also connected to the secondary manifold on the twin Stromberg setup. I cut off the T section and plugged it with a short bolt using JB Weld. Should be good to go. It looks like maybe your manifold has an integrated return port, then a hose to the lower inlet on the firewall?

I’ll have a look in the morning when I’m back in the shop.

I can’t be the only guy who has 3x Webers and likes them. Maybe just lucky, my mechanic dialed them in, they work and sound great, need only yearly cleaning. My series 2 came with them when I bought it about 15 years ago, so far so good.

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Bruce, while you’re looking how is the crankcase breather device up front ported? I see a hose coming off off it but to where? Obviously not to the air filters as with the Strombergs or SU’s.

I love the two DCOE Webers on my Cosworth Vega but I bought them in kit form in the '80s from a Cosworth specialist and they were already jetted etc. for the engine. I have cleaned and re-gasketed them a few times over the years but never deviated from the original internals. I hear the initial set up is the hard part especially with 3 involved but mine have been very reliable with a plugged accelerator pump jet and dirty cold start screen being the only things that have caused running problems in 30+ years. Just check the synchronization and idle mixture occasionally.

68 E-type FHC

Bob, that crankcase ventilation hose just goes down below the frame and is open, it dumps the crankcase pressure straight out to the air - same way it was done for ever before pcv systems came along (my 63 vette is the same).

For the water return, on mine the return goes straight from the firewall to the waterpump. I think what you are looking at in the pic is probably the vacuum hose that goes to the brake vacuum check valve which also goes to the vacuum tank and to the brake servo via the short hose going to the firewall and then a pipe behind the firewall that wanders to the brake servo, eventually, like most things e-type :slight_smile: BTW, thanks for asking the questions cause I’m learning all this one step ahead of you, I’ve had a lot of the car apart, but haven’t had to look at any of this yet.

Thanks again Bruce. I literally took a hundred or more pictures as I began taking the car apart but still not enough or bad camera angles. You’ve helped me solve both problems now!



I’ve had perhaps a dozen engines over the years with Webers. Engines with 1 DCOE, 2 DCOE, and now 4(!) DCNF carbs and never a problem with any of them. The quantity of carbs doesn’t impact the complexity of the calibration process (all throats end up the same), but more carbs do cost more for calibration bits and take more skill to get them flow balanced.

My most recent Weber project earlier this year, the 4 DCNFs, cost about $300 for rebuild kits, idle and main jets to get them fully sorted. Seemed pretty reasonable to me as they will be good for as long as the fuel composition doesn’t change.

As you note, the proper selection of internal components is critical. Once set they are good for decades if kept internally clean. It does take an analytical mind to get the calibration right, and I found it better (cheaper, faster) to do it myself rather than take it to shop. Buy all the Weber tuning books you can find, read and understand them. It should only take about 3 iterations to get things dialed in, assuming you can find some guidance on an initial setting (many sources for that for a 6 cylinder Jag).

Happy to help Bob, I noticed you read a recent (ish) post that I was going to link to for some starting points on setup, mostly I like @Wiggles comment about sounding good and looking expensive, I think I must be compensating …

Here’s the modified water return line connected below the new manifold.

Also, I’ve been looking at how to vent that emissions outlet without leaving oil on my garage floor. Amazon sells many different small “oil catch cans” made for exactly that purpose. I think I’ll go that route.

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If you go the catch can route, just remember to check/empty it every 500 miles or so. Once you figure out how often it approaches full adjust your mileage from there.