Demon 98's against Zenith 228's

[Forty6217]

I was hoping somone could give me some information and direction on the best carbs to run on my 230 Plymouth with a Offy twin carb manifold.

The Engine is 8.5 - 9 to 1 compression, it has an Edgy ground cam 260 duration with .410 lift, balanced, head decked to 79.8cc.

The Offy manifold is a twin carb 2 bolt type, of course the Demon is a 3 bolt, but I do hear you can get adaptors?

The question is which are the best carb's to go for and what is the difference in cost?

[Frank Elder]

Stock carters.....you can't go wrong with the simplicity of the B&B.

[martybose]

I tried a pair of 98's on my 230, but never managed to get them to work right. If they were jetted right for running around town they were too lean at top end, resulting in serious detonation. I was using adjustable main jets, and fiddled constantly with little success. I am much happier with my Carter-Webers.

Marty

[Suddensix]

I agree with Frankie47. My engine is comparible to Forty6217 and I've been running a pair of B&B's for 4 years with no problems and 20 mpg on the highway in O.D.

[Forty6217]

These new Zenith 228 carbs are not cheap they are $650.00 each, they would have to be good dont you think?

[Andydodge]

Assuming you are in the US I'd just use a pair of stock Carter B & B's.........I would think you could get rebuild kits still....here in Oz the carbs and kits are hard to find and as the Offy intake pattern is the same as that used for the local Stromberg single barrel carb that was used by Holden over here then thats what I'm using........and rebuild kits are easy here to.........but that don't help you......lol........I'd stick with a pair of the carters.......andyd

[Forty6217]

Hi Andy its Mike from Canberra, it is funny you should say that the Holden strommys would fit.

I pulled out my offy manifold thinking the strommys would bolt straight up, but they seem to be a different bolt centre.

The stromys are too small the Offy manifold measures 2-15/16' of an inch??

When I bought the manifold in the US and I brought it back I just thought it would fit.

I am not sure what is going on, is the early holden carby a different stud centre size is that why it is not correct?

[greg g]

There were some singles that used a smaller bolt center, I know Studebaker used a 2 3/4 or 2 7/16 deal on their smaller Champion engines. Looked very much like the Carter B1B but with a different (smaller) base. So if your Holde engines were in the same cu inch range 170 +/- them might have sized a similar carb. I believe some earlier Mopar trucks used a similar one and it was an "economy" option on some early 40's Plymouths (perhaps the roadking model).

The after market dual intakes unless set up for 2 bbls uses the 2 15/16 which were common to many cars of the era and across Carter, Rochester, Stromberg etc.

[Forty6217]

There were some singles that used a smaller bolt center, I know Studebaker used a 2 3/4 or 2 7/16 deal on their smaller Champion engines. Looked very much like the Carter B1B but with a different (smaller) base. So if your Holde engines were in the same cu inch range 170 +/- them might have sized a similar carb. I believe some earlier Mopar trucks used a similar one and it was an "economy" option on some early 40's Plymouths (perhaps the roadking model).

The after market dual intakes unless set up for 2 bbls uses the 2 15/16 which were common to many cars of the era and across Carter, Rochester, Stromberg etc.

Thanks for the information, I thought I had bought an unusual manifold, this Offy I have also has a 1-9/16" carb bore size.

Have you heard reports of these Zenith fuel systems 228 carbs. I been advised that they are very good carb, with external main jet adjustment, slide in and options on bore size with different venturis, basically an upspected original?