Throttle ball bearings for Stromberg?

[david.g.chapman]

I have a fair amount of slop in my Stromberg throttle spindles - maybe enough to introduce air into the intake stream.
There is an article on the Buckeye Triumph website about fitting 1810-2rs bearings to the spindles which looks attractive. There are also 1810-zz bearings available which are 7 pounds for a pack of 10!
2rs bearings have a close fitting double seal and zz bearings have a double metal seal with a slight gap.
My question is - what are the chances of the air/fuel intake mixture washing out either of these bearings? Also, Weber carbs use bearings presumably without trouble, and I can't see a seal between the Weber bearings and the intake. So maybe there isn't an issue?

Dave Chapman.

[StressCraxx]

The 2RS bearings should work as long as there is no leakage past the shaft under the bearing and the bearing to the bore of the housing.

Webers have open bearings packed with grease. Most use EZ Turn grease which isn't fuel soluble (Recommended by Keith Franck). The shafts are sealed with leather between the outer washer and the housing bore. The leather is soaked/treated with mink oil, or some use EZ Turn grease worked into the leather.

[elans3]

Later Weber (151 40 DCOE's, & 152's 45 DCOE's), have sealed bearings, I've seen them fitted with 2RS, and ZZ type, and really protect the spindle from wear.
Over the last ten years, (retired now !) I've probably rebuilt 100 sets of these, and never had to either re-throttle shaft or put new bearings in. That tells you how resistant they are to fuel wash-out.
For the price of four bearings, I'd give it a try, although it would obviously be better if you could get new shafts too.

[david.g.chapman]

Thanks StressCraxx and elan3, that's very helpful! I think I'll go down the zz route, possibly with an additional internal shield. Keith's grease is also food for thought.
Cheers,
Dave Chapman.

[69S4]

I have a fair amount of slop in my Stromberg throttle spindles - maybe enough to introduce air into the intake stream.
.

Are you getting any issues with idling or low speed running from 'slop' induced air leaks? I've had a consistent niggle with a high idle speed on my S4 and despite changing the seals it's not improved. I have wondered whether it might be down to air leaks in the spindles but other than the idle speed issue the car runs well.

[JonB]

Question about how you'd do this - I've not looked closely at my Strombergs but I wonder how you'd fit bearings to the spindle shaft. There's no space in the body of the carb, around the shaft, to take a bearing is there?

[david.g.chapman]

If anyone searches for "Stromberg CD175 easy bearings upgrade" on the internet there is a pdf which explains how one guy did it.

As for spindle air leaks affecting performance, I have a lean spitting issue until the carb bodies are warm. I will only really know if anything improves when I strip and rebuild the carbs at the end of the year.
The slop in the spindles may also be causing the throttle butterflies to foul the carb bodies. All will be revealed when I strip down....

Dave Chapman.

[JonB]

https://static1.squarespace.com/static/ ... pgrade.pdf

Thanks Dave, it looks pretty straightforward.

[69S4]

As for spindle air leaks affecting performance, I have a lean spitting issue until the carb bodies are warm. I will only really know if anything improves when I strip and rebuild the carbs at the end of the year.

Dave Chapman.

That's interesting as I have that as well, and it's worse when the dashpots are topped up. I'll be very interested in how you get on with this

[JonB]

OK - following download and reading of the document, I note the author doesn't indicate the thickness (front to back) of the bearing. I spent a while searching and discovered a standard bearing size that appears to be used on remote controlled racing cars. It is R1810-2RS (the 2RS denoting a double rubber sealed bearing). These are 5/16" (7.94mm) inner diameter, 1/2" (12.7mm) outer diameter and have a thickness of 5/32" (3.97mm). I measured the housing depth at 4.95mm so I think these will fit, and allow space for a secondary seal if desired (O ring or similar). In the document he recommends not using shielded bearings (Z or ZZ spec) as "they will leak rapidly and lose lubricant" which makes a lot of sense to me. He also suggests fitting a plastic washer with a smear of grease under once the bearings are seated. Finally, he mentions using a metal epoxy to seat the bearings - I would use proper bearing seating fluid (Loctite) for that.

The R1810-2RS bearings don't appear to be readily available in the UK. Mine come from an European supplier and cost £24 for 10 of them. They are easier to acquire in the US.

I'll update once the bearings have arrived and I've had a chance to fit them.

[JonB]

Quick update.

I fitted four of the bearings to my Strombergs and I'm pleased with the result. I do need to add the plastic washers (covers in this application) mentioned in the document, plus a blob of grease (I'll use waterproof marine grease for this, as it's stickier and thicker than LM grease). The job was relatively easy and I have one spindle that is binding ever so slightly - if I'd taken more time or care this would not be the case. It turns to fully open and returns to fully closed under spring force alone, so not a problem I think. I can't test the carbs yet as the car is under restoration.

Well worth doing IMHO. The old rubber spindle seals were completely perished, and would have let in an awful lot of air, resulting in the usual uneven idle. Fingers crossed for the first start up!