Initial settings and jetting advice for Strombergs

[promotor]

I'm looking for some initial carb settings for a Stromberg engine.

It's a high compression and big valve head (approx 10.25:1) with C-type cams, emission CDSE carbs with Euro spec crossover tube, and 40953 distributor.

I'm not sure which adjustable metering needles to go for.

I'm also looking for initial position settings for the needles and for idle-trimming screws etc for first start-up please.

Any discussion or advice much appreciated!!

[Tonyw]

Promotor,

I have just done this and most of the information I found from looking through the archives, the needle I went for were B1G the jets were .100 the positioning of the jets is fairly important as this basically gives you the starting point, I have set mine at 95 thousanth of an inch below the carb bridge. The jets have to be pressed in and is a delicate little operation.

This has come up a lot and there are various opinions and settings a look in the archives is time well spent.

Tony w

[RogerFrench]

I'd like to endorse everything Tony has said, and make one small comment.

If you have euro-spec inlet manifold, you don't have crossover tubes. They were made for the federal US market, and indeed cross over the engine to the exhaust side in order to warm up the incoming charge.

I suspect that what you're calling a crossover tube is more properly termed a balance pipe or tube, connecting the two inlet runners.

[promotor]

Promotor,

I have just done this and most of the information I found from looking through the archives, the needle I went for were B1G the jets were .100 the positioning of the jets is fairly important as this basically gives you the starting point, I have set mine at 95 thousanth of an inch below the carb bridge. The jets have to be pressed in and is a delicate little operation.

This has come up a lot and there are various opinions and settings a look in the archives is time well spent.

Tony w

Thanks for the advice - what spec is your engine?

I have measured my jets and they are 0.114 below the bridge at the highest part (outer edge) of the jet!

I have gone for BIY needles as I wanted more fuel higher up the rev range to guard against possibility of running too lean as Strommies are a bit notorious for that?

I found the Strommie needle spreadsheet and have saved that for use again as that looks quite handy!

I'd like to endorse everything Tony has said, and make one small comment.

If you have euro-spec inlet manifold, you don't have crossover tubes. They were made for the federal US market, and indeed cross over the engine to the exhaust side in order to warm up the incoming charge.

I suspect that what you're calling a crossover tube is more properly termed a balance pipe or tube, connecting the two inlet runners.

My mistake - well spotted! I do indeed have a balance bar and not crossover tubes. On a side note, did the crossover tubes make the European ECE15 market or where they only in USA?

[RogerFrench]

I understand crossover tubes are unique to the Federal Elans and Europas.