Okay...I bought the fancy polished HS6 SU's. Mounted em on my fancy polished B18B aluminum 2 stack manifold. Replaced the needles with "KD"'s, put in new float needles and seats, watched a bunch of utubes, did the piston drop test, flushed the main jets with inlet structure...backed out 12 flats and fired up...

It runs straight to 2 grand and the float bowls vent gobs of gas...

Square one...It was a B20 E 1971 version when I bought it, but the inject ports were blocked and it had Strombergs on...

I'm still using the original fuel pump. Did B20E Pumps put out higher pressure than B20B-D's???

The engine is a much modded B20E...Schneider 274 cam, oversize Valves, ported head

Needle & Seats: Do you have the Viton tipped + spring loaded version? Solid brass won't do.

Throttle blades: Are they the emissions type with spring loaded over run valves?

Strombergs: Where did they go? I'm not a fan BUT the seperate air bleed for the idle mixture is an ace up their sleeve.

The cam: What specs is it? On the card, what does it say?

O/S Valves? the stock valves are a tad too big for the bore, what have you got?

My choice for in-between twin SU's & twin DCOE's is a good version of Volvo's 38DGES manifold, an adapter plate & a 500cfm Holley 2bbl.

I got the Viton Needle and seats.
The throttle blades are solid, no holes at all
The Strombergs disappeared 12 years ago...
The cam is as follows, but Phil told me to stretch the LSA to 110, and I told them to grind to have the powerband at 2500 RPM-4500 RPM

Grind Number: 274F
Intake Duration (gross): 274
Exhaust Duration (gross): 274
Intake Duration (.050”): 228
Exhaust Duration (.050”): 228
Intake Valve Lift*: .450"
Exhaust Valve Lift*: .450"
Lobe Separation: 108
Intake Valve Lash: .014"
Exhaust Valve Lash: .014"
RPM Range:
2000-6000
The intakes are 2mm oversize, the exhaust 1mm. The head was ported by a local SBC expert, all he did was smooth things out: If I knew how, I'd post a picture...
The Engine runs great, pulls to 6500 and beyond, I have the Rev Limiter set at 6300...If I could stop the Mikuni Float Bowls from weeping...life would be wonderful. They're smaller float bowls than standard, and float level is at minimum possible, I've spent many hours, adjusting the Mikuni floats, 1 mm at a time...
See my new post...the engines runs great on the HS6's, but now they have a mind of their own...

I Just read Dual Springs! LOL So forget that stupid question!

I have to go to bed, the sun came up an hour ago.

So you have 46/36mm Valves?

Cam is not a problem but could be better. Problem with the Volvo head is poor exhaust flow & porting the exhaust actually requires Volvo experience. If he IS a good porter, the inlet will be fine, but be worse inlet/exhaust flow ratio. With high compression, you go bigger on the exhaust. Going back to 220° on the inlet & going as much as 240 on the exhaust would have got you where you needed to go.

Valve springs are?

The Mikunis are insanely oversize. One of them would flow as much as the two HS6's combined. Have you noticed any power loss compared with the carbies changed back to Stock?

You know what happens to older men...they start to assume a LOT...and forget to READ. As my Dad use to say "Thinking with your mouth again?"

The Car is a 142S 1970. when I got it, it had a B20E installed with the inj ports blocked, and two Stromberg CD 175's hanging on a one piece intake/exhaust manifold.
To all the OLD doofuses that think I'm trying to run 2 Carbs off a 40 PSI Electric Pump, way back in the tank, I Say B-L-E-A-A-H!!! I bought new Float needles and Seats from VP. They appear to be the same size of the old bronze/ball bearing ones I took out, but they're much lighter, if anything, they hang up in the UP Position.

I'm going to adjust the float tabs...down a hair and try again tomorrow...

Ron;

You may have watched a "bunch of utubes", but apparently not any where, as Eric notes, it says you sure as hell can't run the >40PSI output of the E FuPu and supply SU bowls with it...I suggest you abandon the FI pump and install a replacement mechanical FuPu (and don't forget the Spacer, unless you want more spilled fuel!)...and the going up to 2 grand is most likely caused by a vacuum leak (or forgetting to install the Throttle return springs).

Cheers

What Spacer???

Mr. Kwas:

My original post states that I bought the car with inj ports plugged and a pair Stromberg CD's...with a mechanical pump ....the only thing B20E about the car is the Engine Block and Head....

Ron;

OK, I stand corrected...I guess I got excited when I read about putting high pressure on the Carbs when I should have read the op again...high pressure like that would certainly cause the overflow...

1. Mech FuPu needs the spacer...see: https://www.sw-em.com/Fuel_Delivery_Components_and_Considerations.htm#Bakelite_Spacer I'd still check the supply pressure is not too high.

2. Bowl Valve body and Seat need to be clean and floats adjusted ...see: https://www.sw-em.com/su_carbs.htm#Common%20SU%20problems and: https://www.sw-em.com/SU%20Carb%20Service.htm#Check_and_Adjustment_of_Fuelbowl_Floats
...yes I read they were rebuilt, but checking these things is good practice, especially now that they are known to overflow...and I like having a "last-chance" filter before the Carbs. Some guys don't like the idea of the plastic ones over the heat of the engine...use the glass envelope ones if that is also a concern you share...see: https://www.sw-em.com/Fuel_Delivery_Components_and_Considerations.htm#Fuel_Filter

Cheers

The electric fuel pump for the fuel injection system puts out way too much pressure.

Volvo originally used mechanical fuel pumps and the fuel pressure should not exceed 4 psi.
--
Eric
Hi Performance Automotive Service (formerly OVO or Old Volvos Only)
Torrance, CA 90502
hiperformanceautoservice.com or oldvolvosonly.com

A Black Spacer about 3/16" thick...it's on there...