Carb advice needed

[sunny67]

I have a 67 Alpine that’s pretty much stock for everything but the motor. The PO installed a later model 1.7 Sunbeam motor with a single carb (yep, it’s a dog). The carb has a choke or cold start attachment. See photo. Gasoline will leak out the choke when I turn on the electric fuel pump. When I remove the choke mechanism from the carb body, there’s no leak. The float level seems to be correct based on what I read and I tried two different float needle valves.
I believe I have the choke disk positioned correctly but not absolutely sure. A photo of the orientation of the choke disk’s 4 holes vs the slot would also be helpful.
Any ideas on my leak? I’m stumped.

 

[Scotty]

A 67 Alpine (Series V) should have a 1725 stock, which is a 1.7L. I've never seen just a one-barrel Stromberg on the Alpine, I bet it's a dog on just that alone...

Electric fuel pump? How much psi is it putting out?

 

[alpine_64]

Can't see the head in the photo but wonder if it's an iron head arrow motor.... Or . If it is an alloy head is the manifold from a arrow series car and it's facing the carb down 10° as the motor is now upright

 

[RootesRooter]

Yup, that's a cast-iron head with single Stromberg, found in the U.S. on the Alpine Coupe fastback and Sunbeam Arrow. 70hp, vs about 92hp on the aluminum-head, dual Stromberg engine.

 

[husky drvr]

Can't see the head in the photo but wonder if it's an iron head arrow motor.... Or . If it is an alloy head is the manifold from a arrow series car and it's facing the carb down 10° as the motor is now upright

Michael,

It's an iron head engine and at least the manifolds and carb appear to be from an Arrow range car. For a more definitive ID, more pictures and the engine and carb ID numbers will be needed.

The manifolds are the same as the ones in Bill Blue's Alpine coupe. The mounted carb linkage here seems to be a hodge-podge assembly of odds and ends. Isn't that a part of a Zenith WI* choke cable mount welded in front?

A photo of the orientation of the choke disk’s 4 holes vs the slot would also be helpful.

S-67,

I'll agree with Michael on the mounting angle having the carb angled more downward than designed.

Here is a link to one of Bill Blue's threads with some pics of Bill's dismounted carb. Beware, there are only a couple of posts about this type carb - as a side excursion - in this thread. Maybe the pics will help.

Carter Side Draft

One of the better kept carburetor secret is the Carter side draft used on the Nash Healey, Corvettes and Corvairs. They came is various sizes, I decided to use a big one, installing it on the Iron Headed 1725 in the '69 Fast back. I decided the carb designed as a performance upgrade for the...

forum.sunbeamalpine.org

I was about to post the link to the site's copy of WSM 145 at the carb section, but after a quick look, I don't think your later style carb is covered there.

Just for a baseline, what are your goals for the car? What are your abilities, experience, and possibly budget?

Hope this helps,

 

[Scotty]

The more I read on this board, the more I learn. I didn't even know this existed. Why did they use just a single carb on an engine that should at least have a deuce?

 

[bernd_st]

Isn't that a part of a Zenith WI* choke cable mount welded in front?

Yes it is. Appearantly spotwelded to the original Single Stromberg choke bracket...

 

[husky drvr]

Why did they use just a single carb on an engine that should at least have a deuce?

No reason to use two when one was able to generate all the power the engine was capable of making.

Bottom line >>>>>> == $...$...$...$ - and the same reasons Fox body Mustangs were offered with four, six, and eight cylinder options.

Cheaper to produce by design and quantity scale of production.

> [ same engine as most Hunter sedans. Found a possible ~ 470,000 production number for Hunters (not sure if that includes "badge engineered" variants) compared to ~ 69,500 for all series Alpines and no clue about Alpine and Rapier coupes ] Here's another fact to surprise you, there was a variant of the Hunter sedan sold as the Hillman Minx, NOT imported here, using an engine with a different crankshaft producing only 1500 c.c. displacement.

Cheaper for the customer to buy.

Probably more reliable due to fewer things to malfunction and keep tuned and/or repaired.

Probably more economical to operate and repair.

Depending on time and location, lower insurance premiums and taxes.

Beginning of "smog" controls - President Nixon signed into law the Bill which created the EPA in December 1970.

Just a few thoughts,

 

[Bill Blue]

I found the single carbed Alpine to drive like a flat head. Good torque but runs out of breath at about 3500. I think they should have put a larger carb on it. Possibly extending the revs up to say, 4500.
Bill

 

[sunny67]

I lowered the fuel pressure and I’ll see if it will solve to problem. It doesn’t always leak so time will tell. It just seems that 2.25 lbs is pretty low but there is only one carb so we’ll see.
As for the car, I added a few pictures. The PO replaced the suspension components, brake components and electrical system but left this tired motor. It’s at roughly 100 lbs of compression in each cylinder. I have a new cam, rebuilt aluminum head and valve cover, 4 stock carbs that need rebuilding, intake and exhaust manifolds and a block that’s been re-sleeved to original bore. I picked these up for a reasonable price just because the were available but I’m still considering a V6.
The PO butchered the interior. So far I’ve found original gauges and rebuilt the dash with curly walnut. He also removed all heater and vent systems and removed the door glass and mechanism. He didn’t save any of the parts. I got everything sourced now and working on reinstalling.

 

[husky drvr]

It’s at roughly 100 lbs of compression in each cylinder.

The engine serial number is for a North American 1969 Alpine coupe ( NOT Alpine GT coupe. No surprise there. )

Compression pressure should be around 160 PSI. Even if it had low compression pistons, which it should not in N.A., then pressure should be around 120 PSI.

Since all four are about the same, the engine seems to be in decent condition. Just with something "off."

Quick question, when you were doing the compression test did you remember to block the carb's piston open as well as having the throttle butterfly open?

Looks to be a nice project.

Your description of the PO's efforts sound like his intention was to build a race car. Is that possible?

 

[rixter]

Hi,

It looks like you have the CDSE carb. I am not suggesting you retain that arrangement, but having used the twin version of those Strombergs on my Alpine 5 for years I may be able to provide some info and photos. I have a few of them off my car as well. Where exactly is the leak coming from? The more common leak location is out one of the vent holes, but you haven't indicated that. I am also curious as to the leak not being present when you remove the cold start mechanism. If that were to be at fault, I'd think the leak would be worse after removal.

Rick

 

[sunny67]

The engine serial number is for a North American 1969 Alpine coupe ( NOT Alpine GT coupe. No surprise there. )

Compression pressure should be around 160 PSI. Even if it had low compression pistons, which it should not in N.A., then pressure should be around 120 PSI.

Since all four are about the same, the engine seems to be in decent condition. Just with something "off."

Quick question, when you were doing the compression test did you remember to block the carb's piston open as well as having the throttle butterfly open?

Looks to be a nice project.

Your description of the PO's efforts sound like his intention was to build a race car. Is that possible?

I did not prop the carb piston up. I’ll do that and try again. it makes since that it would lower the reading. I don’t think the PO had any special plans. He just liked to tinker. I purchased from his son because unfortunately the PO had developed Alzheimer’s and was in a home. He owned it for about 20 years.
I got lucky and found a man that lives about 100 miles from me that had 4 Alpines rusting in a field. He had lots of parts protected in a shed as well as on the cars. I bought 4 carbs, both manifolds, a block, 3 heads, all the parts for door windows and heater/vents, many new rebuild kits, complete new exhaust system, windshield, two complete dashes and gauge set to make one working set, convertible top frame, and many more smaller items. All for about $600. As I said, I got lucky.

 

[hartmandm]

Shouldn't you remove the spark plugs as well for a compression test?

 

[Scotty]

No reason to use two when one was able to generate all the power the engine was capable of making.

Bottom line >>>>>> == $...$...$...$ - and the same reasons Fox body Mustangs were offered with four, six, and eight cylinder options.

Cheaper to produce by design and quantity scale of production.

> [ same engine as most Hunter sedans. Found a possible ~ 470,000 production number for Hunters (not sure if that includes "badge engineered" variants) compared to ~ 69,500 for all series Alpines and no clue about Alpine and Rapier coupes ] Here's another fact to surprise you, there was a variant of the Hunter sedan sold as the Hillman Minx, NOT imported here, using an engine with a different crankshaft producing only 1500 c.c. displacement.

Cheaper for the customer to buy.

Probably more reliable due to fewer things to malfunction and keep tuned and/or repaired.

Probably more economical to operate and repair.

Depending on time and location, lower insurance premiums and taxes.

Beginning of "smog" controls - President Nixon signed into law the Bill which created the EPA in December 1970.

Just a few thoughts,

Wow. Thank you for taking the time to explain this all to me. I'm still learning about the extent of the cars built by Rootes and find the ones I've seen or learned about to be pretty damn cool. I'm sorry if I came off as being a bit dumb.

 

[sunny67]

After setting up cameras and lights so I can see the bottom half better, I now see it’s gas is coming out a number of places around float bowl gasket as well as the choke. That’s telling me that needle valve isn’t seated properly and fuel is coming thru the threads or both needle valves I’ve tried are sticking. What’s strange is that after lowering the pressure, I turned the pump on multiple times over the last few days with no leak. I tried to start it today and fuel gushed out more than ever. I’ll take it apart again.One question.
Am I correct that the float is not hollow and therefore cannot fill up with fuel?

 

[rixter]

This is where mine was shooting out when there was debris in the inlet valve. I would think it is the easiest path out.

Rick

 

[sunny67]

May have found it. It’ll take a few days of not leaking to be sure. I replaced the needle valve for the third time. The engine fired right up which isn’t the norm. It’s always been a hard starter. Fingers crossed.