I've followed the recent post concerning inlet manifold leaks causing symptoms similar to a dead cylinder, and found the same on my B20B twin Stromberg. The carb cleaner was finished, and I will not buy any more since it destroys the diaphrames, so I've used my highly flammable contact cleaner. It's very effective! Anyway, on the one side a nut is missing, but the leak was actually worse on the other side. It has never been removed in 32 years, so I'm thinking of sending it off to a workshop in case I break a stud, or would it be OK to do myself? (I'm an electronic engineer and learn as I go.)

Any other suggestions of things to do while the inlet and exhaust is off? It is a "seperate" manifold set-up.

I've done the carbs early this year (gasket kit), except for replacing the needles. Could not get them out. Any suggestions? Only 112 000 km or 70 000 mi. Plugs burn clean/perfect since carb job. Will probably do valve cover gasket job at the same time.

The absolute biggest thing you can do to improve things is to ditch them strombergs and bolt on a good pair of SUs.

George seems to like the later bottom float HIF units... which are admittedly better in many respects.

I like the earlier side float HS carbs, which are more troublesome, but easier to deal with (in my opinion..)

On a similar note... is there an adhesive sealant that is appropriate for intake/exhaust manifolds? I've used stuff on other cars, but never on the combined gasket that the Volvos use. Something perhaps that could be used only around the intake ports?

-Matt

I find the Strombergs easy to work with. At the moment I'm happy with it, and New Zealand roads do not allow for performance driving. But I do plan on upgrading to FI. I've got an FI manifold in the garage, and will design my own system (electronic engineer). It's a lot of work, but it's what makes me happy. Some people install huge sound systems... The first project, however, is a real time programmable ignition (tune it as you drive). Sure, vacuum and centrifugle advance/retard mechanisms are good, but after 30 years... And tuneable?

I'm still wondering how to remove the fuel metering needle. It is stuck in the piston (yes, grub screw is out). Can I just pull it with pliers, or are there little springs and things that will get damaged?

Thanks
Niel

You can put a couple blocks of softwood in a vise and clamp the needle
between them, then lift the piston with a screwdriver on each side,
sort of a manual puller. Be careful not to bend the needle though.
--
George Downs, The "original" Walrus3, Bartlesville, Oklahoma

Pliers will damage the needle, so don't do that unless you know you'll be replacing it. Have you tried wearing a rubber dishwashing glove? Those give a lot better grip than bare fingers.

I'll do the "wooden blocks" trick. You can see that they've been rubbing against the jet. It has done 111 000 km of mostly city driving, so that equates to lots of actual operating time. What needle number do you suggest for Strombergs? We don't have emissions tests, so I want to go for better performance rather than Volvo recommended.

Thanks
Niel

I seriously doubt that you will have any stud problem. Go ahead and do it.
The big problem is the single bolt/2 manifold washers. If your manifolds
are the same thickness it is OK but if they are different you have to have
spacers to take up the difference so both sides get tight.
--
George Downs, The "original" Walrus3, Bartlesville, Oklahoma

I'm the one with the failing manifold gaskets... I did the job yesterday morning in about an hour and it greatly improved the situation. It now runs strong!! I've had the problem before with another B20, but FI. If even one stud is busted, it will probably leak somewhere. I was dreading the prosp[ect of broken studs, so I bought a set of nine beforehand. The old ones weren't too difficult to get out (use a lot of B'laster or similar penetrating oil). I had to take the vise grips to a few of them and slowly eek them out, but it all worked well. Replacing the studs is a good idea and the use of anti-seize compound is recommended to assist in future removal. This problem seems to be prevalent in most of these engines. After you put it back together, drive it around then park it and let the engine cool for about an hour and re-torque the bolts. If the inlet and outlet manifold thicknesses are dissimilar (like when using a Canon intake with Webers), use trimmed washers to make the surfaces flush to prevent bent studs and pain and suffering. It's not that intimidating once you've done it five times (my 72 FI 145 had a broken stud I never replaced, but kept putting new gaskets on. DUMB!!! It's not that difficult to extract a busted stud with an easy-out screw extractor).

Cheers!

Ben

I've been working on them since 1967 and don't remember ever breaking a
manifold stud. Usually do not use penetrating oil on them.

A good trick for pulling them is to lock 2 nuts together and then you can
unscrew them with a regular wrench. You can put them in that way too.

I've replaced stretched studs but do not replace studs generally unless there
is a problem with them.
--
George Downs, The "original" Walrus3, Bartlesville, Oklahoma

What thread are the studs? I want to get new studs in any case. They are all rusted up, and at least one has a missing nut. In daily use, so I've got to do it right the first time.

One of our mechanical lab engineers is excelent with practical solutions. He recons a high quality silicone sealer will do the job until I get a proper gasket. Will see what expensive stuff we have in the lab, and post the name if it is any good. The car is getting to the stage where I've got to accelerate very slowly to maintain sufficient vacuum on the inlet, and I would not have looked at the gasket if it was not for the "running on 3 cylinders" post.

Thanks a million

Studs are 5/16" NC 20 (or maybe it's 18; I never can remember what the standard pitch is).