The V8 Owners Forum -

mgbv8 wrote:

sidecar wrote:It does matter which way round to a small degree if the manifold is a dual port, the lower ports in the split runners are supposed to be fed by the primary side of the carb, the idea is that the secondary side is heated less by the engine because it is insulated from the engine by lower runners.

I've had them both ways round on dual planes and there was no difference in starting cold or hot. Then again I've never had the warm start issue on the 6 MGB V8 conversions that I've worked on or built ?

Most of the cars I've come across with the primaries to the rear have been done that way because the owners have taken the short route with the throttle cable while knowing no better.

Its down to personal preference I guess. But I always mount carbs with primaries to the front on a fresh build

Dual plane and dual port ain't the same thing, I think that the manifold in the picture is dual port.

(not trying to teach you to suck eggs here!)

You can teach me to suck eggs all you want mate
The difference between young and old is that the old always know that you are never too old to learn stuff eh ?

Yes it does look like a DP manifold having looked at the pic again.

I'm not a fan of the DP to be honest. It was supposed to be a road economy manifold with a low profile wasnt it?

Its certainly not a max power manifold anyway. Again having said that, the carb should still work either way round. Albeit slightly better with primaries to the front?

mgbv8 wrote:You can teach me to suck eggs all you want mate
The difference between young and old is that the old always know that you are never too old to learn stuff eh ?

Yes it does look like a DP manifold having looked at the pic again.

I'm not a fan of the DP to be honest. It was supposed to be a road economy manifold with a low profile wasnt it?

Its certainly not a max power manifold anyway. Again having said that, the carb should still work either way round. Albeit slightly better with primaries to the front?

LOL, I think that Dual ports are pretty bad in terms of making good BHP for the reasons that you state but I did not want to say that as it might upset the OP!

I spent some time talking to V8 Developments about Dual Ports, they will only sell a customer a very mild cam if the engine is going to be fitted with a Dual Port.

Some interesting stuff off topic, So my carb is the wrong way round and my intake sucks (see what I did there).

Only had the car 3 weeks and lots could change, oddly enough it didn't need the low manifold as I had enough room to fit a 1 inch spacer...
I do have another car that could at some point benefit from the low set up on the Stag.. don't you just love cars !

Stu

Camo wrote:Some interesting stuff off topic, So my carb is the wrong way round and my intake sucks (see what I did there).

Only had the car 3 weeks and lots could change, oddly enough it didn't need the low manifold as I had enough room to fit a 1 inch spacer...
I do have another car that could at some point benefit from the low set up on the Stag.. don't you just love cars !

Stu

Hi Stu,

If your lump is totally standard in terms of heads, cam etc then your manifold will probably be OK, they just become restrictive when the engine has been modified to breath better. A good road going manifold is the Edelbrock Performer. Your manifold is still worth a few quid though because on some cars you can only get the carb under the bonnet with a low rise manifold.

The other thing to look at for is that the filter lid is not too close to the top of the carb, that really messes up the air fuel ratio and general breathing of the engine. The Eddy carb is generally setup way too rich for a 3.5 lump, this can cause bore wash. However if the carb was supplied by RPI they are setup way too lean!

I wrote a load of stuff ages ago on these carbs, if you are bored have a read of this....

http://how-to-build-a-pilgrim-sumo.wiki ... ing-system


Pete

Camo wrote:Some interesting stuff off topic, So my carb is the wrong way round and my intake sucks (see what I did there).

Only had the car 3 weeks and lots could change, oddly enough it didn't need the low manifold as I had enough room to fit a 1 inch spacer...
I do have another car that could at some point benefit from the low set up on the Stag.. don't you just love cars !

Stu

Yes Stu!
It does suck. But not much