Does anyone have knowledge on the 425 Dual Quad Ta_20 Camshaft?

[Rivi-98]

Wondering if any of you have run this cam or are running it and how you would say your experience is with them. I have heard low vacuum is an issue but I will get a hydraboost if necessary.

[XframeFX]

1 hour ago, Rivi-98 said:

any of you have run this cam or are running it and how you would say your experience is with them

"Them"? Lucky to find even one testimonial. I searched for feedback on TA's milder TA-112 and Russ M. at nailheadbuick.com kindly remarked it as being a good grind and that they use it in most of their Nailhead builds.

 

Back to your TA-20 request, for a Nailhead? If so, this one?:

http://www.taperformance.com/proddetail.asp?prod=TA_20

This is very likely to be Crower #S372595-005. Actually, I'm certain it is:

https://crower.com/printcamcard/?part_num=s372595-005&x=9&y=10

 

I purchased said TA-112 in January as a just-in-case backup if discovering my camshaft being NG upon disassembly. It turned out to be not bad. Still wanted to proceed with a "fresh" camshaft but the cam-card inside the box revealed a more aggressive profile than I expected. The only difference to the TA-20 you are considering is shorter duration. I was not eager to deal with valve springs and carburetion, I decided not to use this camshaft.

 

I will gladly SELL my TA-112-401 Camshaft to anyone who wants it.

Again, Centerville Auto recommends this profile. Vacuum is said to be good and not so much unburned fuel stink as with longer duration profiles.

 

Before purchase:

1) Ask for a copy of the Cam-Card first! Then compare with that from Camshaft grinder.

2) Consult with an expert (Centerville Auto for Nailheads)

3) Try to purchase as a package with Lifters. Flat Tappet Lifters are dwindling with off-shore items remaining and usually for hollow pushrods only (#969) which supposedly work.

 

I ran the Specs for the TA-20 (Not .470" lift but .480") with 4⁰ built-in advance:

 

 

 

Edited July 11, 2023 by XframeFX (see edit history)

[Rivi-98]

2 hours ago, XframeFX said:

"Them"? Lucky to find even one testimonial. I searched for feedback on TA's milder TA-112 and Russ M. at nailheadbuick.com kindly remarked it as being a good grind and that they use it in most of their Nailhead builds.

 

Back to your TA-20 request, for a Nailhead? If so, this one?:

http://www.taperformance.com/proddetail.asp?prod=TA_20

This is very likely to be Crower #S372595-005. Actually, I'm certain it is:

https://crower.com/printcamcard/?part_num=s372595-005&x=9&y=10

 

I purchased said TA-112 in January as a just-in-case backup if discovering my camshaft being NG upon disassembly. It turned out to be not bad. Still wanted to proceed with a "fresh" camshaft but the cam-card inside the box revealed a more aggressive profile than I expected. The only difference to the TA-20 you are considering is shorter duration. I was not eager to deal with valve springs and carburetion, I decided not to use this camshaft.

 

I will gladly SELL my TA-112-401 Camshaft to anyone who wants it.

Again, Centerville Auto recommends this profile. Vacuum is said to be good and not so much unburned fuel stink as with longer duration profiles.

 

Before purchase:

1) Ask for a copy of the Cam-Card first! Then compare with that from Camshaft grinder.

2) Consult with an expert (Centerville Auto for Nailheads)

3) Try to purchase as a package with Lifters. Flat Tappet Lifters are dwindling with off-shore items remaining and usually for hollow pushrods only (#969) which supposedly work.

 

I ran the Specs for the TA-20 (Not .470" lift but .480") with 4⁰ built-in advance:

 

 

 

Good write up, I did contact Centerville and they claimed that a TA_20 they tested was around 14" Vacuum at 500-600rpm, but that was on a ported intake/head 401. I will bite the bullet and give it a whirl. Will report back my findings for future reference/buyers on the TA_20 Dual Quad setup.

[XframeFX]

58 minutes ago, Rivi-98 said:

Will report back my findings for future reference/buyers on the TA_20 Dual Quad setup.

Yes, please do! 

Often advise is requested. But, seldom do we hear of any results.

 

I will post an image of the nylon camshaft sprocket in another post for those still running it. Because . . . . I was sitting on pins & needles thinking a failure is imminent on a road trip far from home. Turns-out, it was not a "ticking time bomb" as I thought!

 

On a test drive last summer, I swung by the Upholsterer. He was impressed not only with the results but quote: "Of all the auto seats we've done, you are the only one to come back to show the finished product!"

[telriv]

I have NOS Coyles nylon camshaft sprockets in stock if anyone is looking for one.

 

Tom T.

[drhach]

What are you looking for in terms of performance from the TA-20? I'm running a TA-112 (rebranded Crower). The car pulls tons of vacuum (with 10:1 pistons), has plenty of power. I don't know how it stacks up to other cams. But it suits me fine. 

[Rivi-98]

1 hour ago, drhach said:

What are you looking for in terms of performance from the TA-20? I'm running a TA-112 (rebranded Crower). The car pulls tons of vacuum (with 10:1 pistons), has plenty of power. I don't know how it stacks up to other cams. But it suits me fine. 

I am looking to get back to the closest dual quad cam the Super wildcats shipped with. I have a 65 401 and would like to build it up to Buick specs like their their Duo Quad setups and the TA_20 is the closest I have seen other than the really expensive (and rare) OEM 091 Super Wildcat cam.

[RivNut]

Take a look at the chart I’m attaching. The dual quad cam is the same cam as was used in other stock factory engines.  There is no special Super Wildcat cam.  It’s the same as the 1963 401 cam and the late 63 425 and 64 425 cams, and 65 425 cams.  The only difference is the width of the groove in the shank.  The distributors are different.
 

Edited July 12, 2023 by RivNut (see edit history)

[NTX5467]

I'm wondering just how much of that .480" lift is really needed or past the max-flow lift of the cyl head ports?  All things considered. 

 

That much lift with the shorter duration can also lead to valve spring fatigue, more than if it was more like .450" lift.  Any machining of the valve guides tops for that .480" lift?  Might need to consult with Russ on these things?  Just to make sure.

 

Just some thoughts,

NTX5467

[telriv]

The MAX you can go on valve lift stock is close to .490". 

BUT in reality with the stock rockers that's closer to .410".

So there is plenty of room with a stock set-up.

The ONLY TIME the rocker ratio is 1.6-1 is with a lobe lift of .250" ANYTHING  above that (.250"x1.6 actually equals .400" lift at the valve) & the ratio gets cut down drastically to the point where you would be lucky IF it's 1.4-1 & even 1.1-1 as you keep going up on lobe lift.

I know it's hard to understand BUT after years of experimenting the ONLY WAY you can get ANY EXTRA lift is to increase the rocker ratio. 

 

Tom T.

[Rivi-98]

13 hours ago, RivNut said:

Take a look at the chart I’m attaching. The dual quad cam is the same cam as was used in other stock factory engines.  There is no special Super Wildcat cam.  It’s the same as the 1963 401 cam and the late 63 425 and 64 425 cams, and 65 425 cams.  The only difference is the width of the groove in the shank.  The distributors are different.
 

I did look into this, and all the repo cams I have found are more of a blend of various 401 425 cams ta112 does look very smooth comparatively to the ta20. Thanks for the chart saving that for sure.

[Rivi-98]

13 hours ago, RivNut said:

Take a look at the chart I’m attaching. The dual quad cam is the same cam as was used in other stock factory engines.  There is no special Super Wildcat cam.  It’s the same as the 1963 401 cam and the late 63 425 and 64 425 cams, and 65 425 cams.  The only difference is the width of the groove in the shank.  The distributors are different.
 

The distributer difference is simply a fly weight change right? I have a beautiful 59' Cast Iron Distributer I was planning on using, and my recurve machine indicates it's almost Identical say a degree or 2 off from the Super Wildcat dist at the crank. 

[RivNut]

Tom Telesco can set up a distributor for you. 

[telriv]

It's MUCH more than simply JUST  a flyweight change.

Vacuum ALSO has a part in all this.

 

Tom T.

 

 

[JZRIV]

I installed the TA-20 and vacuum was an issue. Not quite enough for consistent brake booster operation let alone old A/C vacuum controls that need all the boost they can get. I think it was around 12" at 700 rpm. Would have been OK if I brought idle speed up to 1600rpm but I wasn't doing that. At the time you could get that grind with a 112 Lobe Center but it wasn't in stock so I got the 110 and was promised vacuum would be fine. Only afterward in troubleshooting and making calls I learned from Jerry Cantrell (Schneider Cams who grinds them) NO it wouldn't be fine. He said the 112 LC would improve vacuum maybe 1.5-2" at normal idle which is still marginal in a car like a Riviera. 

Bottom line I was very disappointed and changed the cam.

Nothing better than the Factory 091 dual quad cam for a Riviera....which is NOT available. Buick engineers who designed it back in the day knew what they were doing.

I always wondered why a camshaft maker never duplicated that grind.

Thankfully Telriv set me up with an original 091 cam for which I am grateful to this day.

Edited July 13, 2023 by JZRIV (see edit history)

[RivNut]

53 minutes ago, JZRIV said:

I installed the TA-20 and vacuum was an issue. Not quite enough for consistent brake booster operation let alone old A/C vacuum controls that need all the boost they can get. I think it was around 12" at 700 rpm. Would have been OK if I brought idle speed up to 1600rpm but I wasn't doing that. At the time you could get that grind with a 112 Lobe Center but it wasn't in stock so I got the 110 and was promised vacuum would be fine. Only afterward in troubleshooting and making calls I learned from Jerry Cantrell (Schneider Cams who grinds them) NO it wouldn't be fine. He said the 112 LC would improve vacuum maybe 1.5-2" at normal idle which is still marginal in a car like a Riviera. 

Bottom line I was very disappointed and changed the cam.

Nothing better than the Factory 091 dual quad cam for a Riviera....which is NOT available. Buick engineers who designed it back in the day knew what they were doing.

I always wondered why a camshaft maker never duplicated that grind.

Thankfully Telriv set me up with an original 091 cam for which I am grateful to this day.

Other than the width of the groove in the shank, what is the difference in the 2nd, 3rd, and 4th cams from the right in Dennis Manners chart? Are there specs that are not published? 

[Rivi-98]

2 hours ago, JZRIV said:

I installed the TA-20 and vacuum was an issue. Not quite enough for consistent brake booster operation let alone old A/C vacuum controls that need all the boost they can get. I think it was around 12" at 700 rpm. Would have been OK if I brought idle speed up to 1600rpm but I wasn't doing that. At the time you could get that grind with a 112 Lobe Center but it wasn't in stock so I got the 110 and was promised vacuum would be fine. Only afterward in troubleshooting and making calls I learned from Jerry Cantrell (Schneider Cams who grinds them) NO it wouldn't be fine. He said the 112 LC would improve vacuum maybe 1.5-2" at normal idle which is still marginal in a car like a Riviera. 

Bottom line I was very disappointed and changed the cam.

Nothing better than the Factory 091 dual quad cam for a Riviera....which is NOT available. Buick engineers who designed it back in the day knew what they were doing.

I always wondered why a camshaft maker never duplicated that grind.

Thankfully Telriv set me up with an original 091 cam for which I am grateful to this day.

I figured that would be the case, but I have a pretty odd Riviera it has the factory AC Delete and Radio delete. So I figured if I could get enough vacuum for the distributors advance and booster I would be ok. Must have glanced over you daying you had 12" at 700 sorry. Did you happen to port your intake/heads before doing the vacuum gage test or was it stock?

Edited July 13, 2023 by Rivi-98 (see edit history)

[telriv]

As far as I know it was completely stock.

 

Tom T.

[JZRIV]

22 hours ago, RivNut said:

Other than the width of the groove in the shank, what is the difference in the 2nd, 3rd, and 4th cams from the right in Dennis Manners chart? Are there specs that are not published? 

Ed - It is my understanding those 3 cams are identical. All with 109 spacing/lobe separation. So yea, find a stock 63 with an original "optional" 425 with good internals and original distributor and you have a very strong running engine. I always thought the 63s with 425 would be so much more sought after if they didn't have the Dynaslow tranny. 😏 

[JZRIV]

16 hours ago, telriv said:

As far as I know it was completely stock.

 

Tom T.

Yep completely stock throughout. I wanted the driving experience to feel EXACTLY like it would have been when the 66MZ was new. 

[NTX5467]

Aftermarket cam companies can't exactly duplicate anything the OEMs did, just offer their version of "equivalent to" products.  Usually, such cams have different timing events for a similar total duration, a bit more valve lift, and such.

 

In Dennie's talk at the Flint Anniv Meet, he noted that the Riv GS cams were a bit milder than the similar cams in a Skylark GS, usually with a bit less exhaust duration.  Needed more torque for the heavier Rivieras, he mentioned.

 

Did the cam bearing sets change with the groove/no groove situation of the cams?  Just curious, as the groove situation could be one way of denoting which vendor did the cam production?

 

Take care,

NTX5467

[telriv]

NO

Cam bearings are the same '57-'66

 

Tom T.

[TKRIV]

I am running my 425 on TA-112-401 on Dual Quads and am happy with it's drivability and performance.

Made a minor change on metering rods and it drives sweet.

No problems with vacuum. 

Tom K

[Rivi-98]

6 hours ago, TKRIV said:

I am running my 425 on TA-112-401 on Dual Quads and am happy with it's drivability and performance.

Made a minor change on metering rods and it drives sweet.

No problems with vacuum. 

Tom K

It's not too lopey is it?

[TKRIV]

This is a mild cam. Not lopey. I selected this cam and not the TA-20 as I did 

not want any vacuum headaches.

[Rivi-98]

3 hours ago, TKRIV said:

This is a mild cam. Not lopey. I selected this cam and not the TA-20 as I did 

not want any vacuum headaches.

Sounds like the way I'm gonna go thanks for the input!

[Rivi-98]

On 7/13/2023 at 11:51 AM, telriv said:

It's MUCH more than simply JUST  a flyweight change.

Vacuum ALSO has a part in all this.

 

Tom T.

 

 

So was GM using the high initial timing on the dual quads as a way to improve manifold vacuum or was that strictly to improve the burn of the much added fuel consumption? It would seem to me a KX Distributer would increase vacuum through all ranges maybe that is a way to gain a little more vacuum?

Edited July 19, 2023 by Rivi-98 (see edit history)

[telriv]

Much better throttle response with little to no air going through the throttle blades as ALL throttle plates are supposed to be closed & blocking ALL or MOST incoming air.

Vacuum advance is hooked to ported vacuum & NOT manifold vacuum as others.

Don't forget when you step on the go pedal vacuum will be heading to zero depending on how hard you press.

SO it as little to nothing to do with gaining any further vacuum.

There is no way to increase vacuum when you step on the gas UNLESS you are very light/gentle on the pedal.

 

Again, just my thoughts.

 

Tom T.

.

[NTX5467]

If you look at the OEM vac advance specs on almost any engine, the vac advance starts at about 9" Hg and is maxed-out by 14" Hg, which is a somewhat limited window of advance for the unit.  It should work in concert with the mechanical advance map, too.

 

Typically, vac advance is run by ported intake vacuum, not 'manifold vacuum", although once the throttle is opened past the ported vac supply port in the throttle body, the two CAN be the same.

 

To me, a key point in "learning the equipment" is to NOT floor the throttle off-idle, but use a 1/2 throttle punch initially, then increasing it before the normal 1-2 shirt.  This keeps manifold/ported vacuum higher for a more efficient level of performance.  Once intake manifold vac drops to where the vac advance in not at play, you have to rely strictly upon pure mechanical advance (which can be a bit slow, sometimes).  Finding that "sweet spot" can make driving fun and more enjoyable as the car is having fun, too.  And it can use LESS fuel, too, as the carb is not fully into the enrichment phase of its mixture curve . . . even better.

 

Just some experiences,

NTX5467

[XframeFX]

On 7/18/2023 at 5:02 AM, TKRIV said:

I am running my 425 on TA-112-401 on Dual Quads and am happy with it's drivability and performance.

Finally, a testimonial on the TA-112-401 I purchased in January!

So, one review and a good rating. Russ M. uses a similar grind in 95% of his nailhead builds.

I was concerned with the enclosed cam-card stating .480" Lift.

Here's one of many posts on this:

On 7/12/2023 at 6:24 PM, telriv said:

The ONLY TIME the rocker ratio is 1.6-1 is with a lobe lift of .250" ANYTHING  above that (.250"x1.6 actually equals .400" lift at the valve) & the ratio gets cut down drastically to the point where you would be lucky IF it's 1.4-1 & even 1.1-1 as you keep going up on lobe lift.

I know it's hard to understand BUT after years of experimenting the ONLY WAY you can get ANY EXTRA lift is to increase the rocker ratio.

"Hard to understand"? No, you explained it well!

Speaking Lobe Lift, why go beyond the spec of .250ish of the 1963 #1359442 original? Wouldn't a .300" Lobe Lift put extra wear on valve guides and and rocker arm tips? Also, Russ M. recommends upgraded valve springs even with the TA-112-401 camshaft. Upper RPM will be a challenge with original springs.

I think it best to stay original. Or replace with an Elgin or Melling (same camshaft) which has a stock profile in it's grind.

 

That Dennis M. List is not very useful as none of those camshafts are available and it uses the .002" lift criteria. Good for ID'ing and comparing cams on that list, that's about it.

 

Sourcing New Hyd. Lifters appears daunting. Lots of recent camshaft break-in failures being posted. I know you can't believe everything online. But, numerous youtube postings indicate faulty lifters as the cause.

Purchasing a set of 16 is much cheaper than individual lifters. However, who produces a quality Hyd. Flat Tappet Lifter that doesn't require dis-assembly for cleaning and successful break-ins?

 

[telriv]

NO ONE.

Cam & lifters need to be, IF I remember correctly, a hardness of 62 on the C-Scale, IF you check them they usually are.

ONLY problem is they don't go as deeply as manufactured in the past.

Reason for ALL the cam & lifter failures.

AND IF it goes flat while breaking in you need to start the rebuild ALL OVER as the metal particles are through-out the engine.

Don't get into a false sense of security by changing the oil & filter many times.

It usually doesn't work out.

You can replace the inner springs ONLY for about an extra 15 lbs. of pressure.

Not an overly amount of pressure.

Yes the more lobe lift the more wear/stress on ALL the related components being that the original rockers are so short & stubby.

That's where ROLLER ROCKERS come into play with a larger RATIO.

Now eliminates ALL that stress & wear with a performance boost to boot, although quite costly.

It's ALL ABOUT GETTING THE AIR IN & OUT.

ALL the stock cams are about 207-208 @ .050".

 

Tom T.

[XframeFX]

On 7/21/2023 at 3:02 PM, XframeFX said:

Who produces a quality Hyd. Flat Tappet Lifter that doesn't require dis-assembly for cleaning and successful break-ins?

 

On 7/21/2023 at 4:21 PM, telriv said:

NO ONE.

So, at a local Speed Shop, I was informed of Comp Cams newest product, their #812D Flat Tappet Hyd. Lifters. Unfortunately the part number is for Chevys only. Hopefully other applications will follow.

They appear to be good but, coated? Only $124 for 16? Being NEW, no customer track record. Hate to be a guinea pig for this one so, Chevys can be it!

https://www.compcams.com/high-energy-dlc-hydraulic-flat-lifters-for-chevrolet-small-and-big-block.html

[telriv]

One of the only diff. between the Chev lifter is that the pushrod cup sits .060" lower than a "Nail". 

The other diff. is the pushrod cup is 5/16ths. as opposed to 3/8ths. for a "nail".

Now you need hybrid pushrods that are 3/8ths. on one end & 5/16ths. on the other.

You can use a 5/16ths. pushrod in a 3/8ths.cup but NOT a 3/8ths.pushrod in a 5/16ths.

 

Tom T.

[drhach]

On 7/19/2023 at 8:38 AM, Rivi-98 said:

So was GM using the high initial timing on the dual quads as a way to improve manifold vacuum or was that strictly to improve the burn of the much added fuel consumption? It would seem to me a KX Distributer would increase vacuum through all ranges maybe that is a way to gain a little more vacuum?

After having installed dual carburetors, I would say the "much added fuel consumption" notion is pretty false. If it is tuned correctly, you'll use the same amount of fuel that you would have used with an appropriately sized 4 barrel. I changed from a Quadrajet to this setup and the fuel economy is about the same. I have a progressive linkage and I can feel in the pedal when the second primary opens. Most of the time, I don't even use the second carb, let alone both secondaries. 

[EmTee]

6 hours ago, telriv said:

Now you need hybrid pushrods that are 3/8ths. on one end & 5/16ths. on the other.

Or an adapter disk/shim that sits between the top of the lifter and the bottom of the pushrod.

[NTX5467]

In any metallic interface, there usually is ONE sacrificial wear item.  Usually, it's the bottom face of the valve lifter.  If one degrades too much, easy to replace.  With the new COMP lifters having a harder bottom surface, that might well make the cam lobes to be the sacrificial wear item?

 

So, is the coating there for friction reduction or wear reduction?

 

I COMPLETELY CONCUR with the use of roller-tip rocker arms.  Yes, more expensive, BUT the possible reduction of wear in the valve guides (and valve stems) should be significant.  My late machine shop operative noted that as the guides wear, due to sideloads placed on the valve stems by the rocker arms, the wear increases to the point where as the valve seats, it can hit the seat a bit crooked and not seat squarely and firmly as if it was less worn.  Certainly, the force of the valve spring might counteract some of this, but not all of it, I suspect.  End result is a minor hot spot on the edge of the valve, where it is thinnest, which continues to cook away until a flat spot exists on the circumference of the valve head, i.e., "burnt valve".

 

Some might disagree, but to me, the best valve guide upgrade is the bronze heli-coil type valve guide inserts.  Not hard to install.  Do a valve job first, as everything centers off of the valve seat.  Then cut the grooves into the existing guide.  Then install the bronze heil-coil insert.  Use the appropriate tool (in the installation kit) to seat the heli-coil in the grooves.  Burnish/trim the ends and you're done.  Lube the valve stems and install valves, springs, retainers, and valve stem locks.  Allegedly this type of guide has a very good wear interface with chrome-stemmed valves.  PLUS, should they ever wear, put in new bronze heli-coils and go again, it seems to me.  A "forever" repair for a vehicle which does not see much use?  Like adding a double-roller timing chain in place of a normal one.  To me, both of these are incognito upgrades for longer intervals between "take aparts", which with other quality parts and machining, can extend the life of any engine well WELL into and past the 200K mile mark, by observation, with oil changes every 4000 miles or so.

 

As to the timing chain upgrade to a double-roller design, I put one in my '77 Camaro at 92K miles.  When we replaced the engine at 525K miles (for leaking freeze plugs, all of them), it was still working fine.  Never had to re-set the initial timing, either.

 

Just some thoughts and experiences,

NTX5467

[Rivi-98]

22 hours ago, drhach said:

After having installed dual carburetors, I would say the "much added fuel consumption" notion is pretty false. If it is tuned correctly, you'll use the same amount of fuel that you would have used with an appropriately sized 4 barrel. I changed from a Quadrajet to this setup and the fuel economy is about the same. I have a progressive linkage and I can feel in the pedal when the second primary opens. Most of the time, I don't even use the second carb, let alone both secondaries. 

Good to know, I did go ahead and spring for the progressive linkage so maybe it won't be too bad. Off topic but how bad is heat soak with the dual carbs?

[drhach]

3 minutes ago, Rivi-98 said:

Good to know, I did go ahead and spring for the progressive linkage so maybe it won't be too bad. Off topic but how bad is heat soak with the dual carbs?

When I installed the duals, I added an O2 sensor.  Mostly for tuning purposes. But heat soak also shows itself as a rich condition when the fuel gets hot and tries to boil over. If left long enough, it would turn in to a lean condition. The car always starts when it's hot outside, but I have observed the fuel mixture changing quite a bit when idling in traffic. My intention was to add a return type fuel filter to keep processing fresh cool fuel through the system. But generally, it doesn't affect drivability or restarting in how weather. The car now also had much more fuel in the floats than it had with the Q-jet. With the Q-jet, if the car sat more than two days, the float bowl would be empty. Now the car can sit for a week or two and still fires right off. 

 

As they say, 'your mileage may vary". But in this regard, I think the duals are quite an improvement over the Q-jet. 

 

Regards,

Dan 

[RivNut]

2 hours ago, drhach said:

 The car now also had much more fuel in the floats than it had with the Q-jet. With the Q-jet, if the car sat more than two days, the float bowl would be empty. Now the car can sit for a week or two and still fires right off. 

 

As they say, 'your mileage may vary". But in this regard, I think the duals are quite an improvement over the Q-jet. 

 

Regards,

Dan 

Typical of a Q-jet.  When I had the Q-jet rebuilt for my ‘73 Pontiac Grand Am (man what a fun car) the rebuilder epoxied the plug into the bottom of the carb - no more empty float bowls.

[drhach]

I think that thimble sized float bowl was my only real complaint about that carb. I've heard that was why the Thermoquad was developed.