Project: 1939 Jaguar SS100 Replica Classic Roadsters, LTD. "Duke"

[Bruce Nunnally]

Squashed threads, repair, discovery of another issue, repair, and now we need to wait for the proper keyed linkage parts to come in the mail.

Here you can see the squashed threads on the carb linkage attachment rod

I took the carb bolt to the hardware store and discovered what the equivalent threads are -- 8 mm 100 (fine)

then got a die and 2 new bolts.

Chased threads look a bit better

New retaining bolt in place along with the rest of carb linkage assembly to drive the secondary

This Toyota OEM linkage was the piece that the engine swapper re-used instead of a correctly keyed linkage piece.

I believe this is the root cause.

The linkage has never has a smooth movement. In the center of this pic you can see a silver screw head that is up against another pieced

I disassembled the choke and associated hardware to get in to that screw and tightened it up, which keeps the upper linkage to the choke

from having excessive lateral play, and allows the linkage to move smoothly.

Now I need to wait for a proper linkage kit to come in the mail so I don't re-create. With proper keyed linkage bits the retaining bolt is

not a load bearing retainer -- it just needs to tighten enough to keep things from coming apart with no lateral stress.

The repaired threads should work for that. It used a washer with a locking tab to prevent backing out.

[Bruce Nunnally]

View looking down at the linkage; just at the left end of the round wheel-like throttle linkage you can see the new lever peeking out.

I think I found an appropriately carburetor solution. I added a lever that goes from the back of the Toyota throttle and transmission linkage to the Weber 32/36

keyed linkage part. This transfers the torque from the throttle through the lever to the keyed linkage, so preventing slippage or issues from the non-keyed

Toyota OEM part.

Close-up of the lever from the bottom prior to reassembly on the Roadster

I have the Roadster back together. Happily no issues with intake leaks after taking the carb stack back off and on again.

Minor re-do with the fuel line to carb; that would really like to be a fitting instead of hose clamp.

The linkage screw fix is working well -- there was a sort of hard spot when you first pushed the gas pedal before and

now it is smooth throughout if perhaps too soft. The Roadster is driving well; although it rained here today I was able to

take it out and around the block to test.

I have more hardware on the way so if this doesn't stay fixed I have options, but this seems to be a good solution.

[Cadillac Jim]

Are you using gasket sealer at all on the carb stack? I'm not at all sure that you are supposed to, but I would look at the rebuild kit instructions about that if you are having any leaks at all.

[Bruce Nunnally]

Ran a new baseline today for comparison with future runs after linkage repair.

Run num Speed(mph) Time(s) Dist(f) Graph run Description

2 0.00 0 0.00 Speed Start
2 10.00 1.12 8.64 Speed Line
2 20.00 2.58 41.30 Speed Line
2 30.00 4.45 110.04 Speed Line
2 40.00 6.50 215.68 Speed Line
2 50.00 9.16 392.01 Speed Line
2 60.00 13.29 726.73 Speed End

Prior run 10BTDC test (timing unchanged)

Run num Speed(mph) Time(s) Dist(f) Graph run Description

4 0.00 0 0.00 Speed Start
4 10.00 1.06 8.36 Speed Line
4 20.00 2.54 41.89 Speed Line
4 30.00 4.48 113.21 Speed Line
4 40.00 6.62 223.40 Speed Line
4 50.00 9.46 413.15 Speed Line
4 60.00 13.63 750.79 Speed End

Red line is today's run at 13.3 sec. Blue line is the 10BTDC run from the timing comparison tests at 13.6 sec. Timing still set at 10BTDC. Runs are not corrected for temperature; today was 77F prior was 84F.

On visual examination after the run choke was fully open. WOT AFR was ~11.7:1 at higher RPM.

[Texas Jim]

Looking much better...

More torque from 1500 to 5200...

More HP from 1500 to 5200...

Just a hair slower from 0 to 20... but after that all times are better...

[Bruce Nunnally]

I suppose overall we have established a baseline around 61-65 (as high as 68, low as 56) whp. Now as we actually get into mods -- header, intake -- we hope to see improvements from the

baseline.

[Bruce Nunnally]

Received the 32/36 air horn and did initial install. No instructions came with the air horn, or are available on the website.

No instructions, and assembly is a bit tricky -- two of the bolt need to go into place with the top of the carb off, two can go into place

with the top of the carb on and the bottom of the air filter on etc.

The bolts and nuts make sense, but their placement leaves the allen-head bolt head covered from below on my 32/36, so it is hard to get some of them really tight.

I took the Roadster around the block and warmed it up but didn't have time to do a full test tonight.

Still doing fitment checks to ensure the hardware is staying in place etc. The new air horn would make

getting into the carb to change jets a lot more trouble. If it is not a nice add in my testing, then it will

go back into the box.

Tests have shown that using a nylon lock nut on the standard filter mounting studs, backs them

out when loosening the lock nuts. That is the reason for adding the M5 SHCS as shown in the

pictures (side view). They are mounted from the bottom of the top half of the carburetor.

I am not clear on what the 'best' fitment would be for the new air horn, but I think a press-fit onto the

32/36 air horn and no engagement with the air filter bolt holes would have been better. What the kit

does instead is replace the threaded bolts from the air filter assembly with bolts and nuts that pass

through the threaded holes in the carb top and into the air filter assembly. This is good on paper,

but on the carb the bolts can't fit in place unless the carb top is off, but the carb top has to be on

before you put on the air filter bottom, so it is a dance to get it all put together, and then the access

to the bolt heads is useless in 2 cases.

[Bruce Nunnally]

Took the carb off again this morning to reset the electric choke and tighten the air horn bolts.

With carb in my lap it is easier to get to at least one air horn bolt at each end so I think I have that in a good state.

The electric choke had to come off the carb for the linkage repair so needed reset.

The choke is a heated coil affair. When cold it contracts, closing the choke butterfly.

As the engine runs, electric current heats the coil, causing it to open the choke

Butterfly. Proper adjustment is done at 68f or below. The choke housing is

rotated so that cold the choke butterfly is closed at 1/3 throttle.

Unfortunately after my test drive of a few min the choke was still not fully open,

Suggesting an issue in power or adjustment. The linkage is properly actuating

So the butterfly opens on throttle but the carb will need to come off again on

A colder morning for adjustment. I am not a fan of the electric choke, but

clearly I just don't get it yet.

Next is choke adjust and / or air horn tests depening on the weather.

[Texas Jim]

Electric chokes are good.... They work well, when properly adjusted.

If I am adjusting it when cold, I want it just a tiny bit more than barely closed when cold.

It goes against what a lot of instructions say, but I usually adjust them when "HOT" to be fully open and then check it on a cool day to make sure it is "RIGHT".

This is the way I check it.

When I park it at operating temp, I take the air cleaner off and check if choke is fully open.

Then after it cools off, preferably several hours, I open the hood to check if the choke is still fully open. and do not touch the linkage yet.

Now.... If choke was open when hot, and is still open, (and it should be) ... I reach over, using the throttle linkage and OPEN the butterflies.

If the choke is adjusted "RIGHT" it will "SNAP" closed.

If it doesn't do that, then adjust it by rotating the choke housing just a bit till it is closed.

Then check when hot to make sure it is still OK when hot.

[Bruce Nunnally]

Nice write-up on the choke adj. I adjusted the electric choke hot to ensure we had open butterflies for a test run. I'll look at it cold in the morning

for confirmation.

89F for today's test run of the Weber 32/36 carb air horn.

I held the run a bit past 6000 rpm. I am not actually trying to minimize 0-60 times so much as measure the power to 6000

rpm in first gear.

Run num Speed(mph) Time(s) Dist(f) Graph run Description

2 0.00 0 0.00 Speed Start
2 10.00 1.18 8.69 Speed Line
2 20.00 2.69 42.54 Speed Line
2 30.00 4.58 112.03 Speed Line
2 40.00 6.66 219.07 Speed Line
2 50.00 9.46 405.14 Speed Line
2 60.00 13.50 730.44 Speed End

The engine pulled well near 6000 rpm, but fell on its face mid-way around 40-50 mph.

Previous:

Ran a new baseline ... for comparison with future runs after linkage repair.

Run num Speed(mph) Time(s) Dist(f) Graph run Description

2 0.00 0 0.00 Speed Start
2 10.00 1.12 8.64 Speed Line
2 20.00 2.58 41.30 Speed Line
2 30.00 4.45 110.04 Speed Line
2 40.00 6.50 215.68 Speed Line
2 50.00 9.16 392.01 Speed Line
2 60.00 13.29 726.73 Speed End

Today's run in Green:

Looks very promising at higher RPM but big issue around 3000 RPM. Overall slower time than without, but shift point could have contributed to timing. Compare Red to Green for before/after.

Today's green run is 6 hp better at 5900+ RPM, but that surprising trough at 3000 rpm is 15 hp worse.

[Texas Jim]

That is a strange anomaly between 2500 and 3500...

Wonder what caused that ????

[Bruce Nunnally]

On the very first runs, which had way too much timing -- we saw a similar effect. That is the range that the centrifugal timing comes on.

Look at the blue run here (needs to be recalc for correct final drive)

here is that data re-cast with proper final drive and in comparison today's run except I don't have the proper temp correction info.

Not saying it is correct, that I understand why it happens, or that it is not 'just' a tuning or AFR problem, just pointing out that I have seen that shape.

[Texas Jim]

My first thought is the advance somehow STUCK for a second or two and didn't advance...

That's a really odd curve...

[Bruce Nunnally]

Yes. I would like to get another couple of comparison runs and see.

[Cadillac Jim]

What does the A/F show during the dip?

[Bruce Nunnally]

I think our AFR has gone to 11.7:1 at WOT now. I am not certain what it read during this run.

Box in the mail today with the Offenhauser Series C intake manifold for the Weber 32/36 and 3TC

Hopefully installation and test soon; have to order a gasket, and want to re-run tests w current config.

[Bruce Nunnally]

Re-ran some tests on the current configuration, with the new 32/36 air horn still in. Temps were 86F, baro 29.88.

Lots of wind, but never got sorted out with or against; weather report says 15 mph South, so neutral.

First run I shifted at 6000 rpm as normal, and did a 13.7 sec 0-60. Second run I held first to 6200 rpm, but only got to 59.1 mph doh.

Third run I focused on the gps meter, and held 1st gear until it went past 60 mph. This took 14.7 sec. Much slower, but not the point.

I wanted to hold first because the way that I sample the data is from the 0-60 run data and I wanted it all in first gear so we can see

the 'rest' of the curve to 6200 rpm.

Run num Speed(mph) Time(s) Dist(f) Graph run Description

2 0.00 0 0.00 Speed Start
2 10.00 1.11 8.74 Speed Line
2 20.00 2.62 42.62 Speed Line
2 30.00 4.53 112.74 Speed Line
2 40.00 6.63 220.86 Speed Line
2 50.00 9.45 408.16 Speed Line
2 60.00 13.70 752.78 Speed End

3 0.00 0 0.00 Speed Start
3 10.00 1.16 8.69 Speed Line
3 20.00 2.67 42.45 Speed Line
3 30.00 4.59 113.04 Speed Line
3 40.00 6.76 224.86 Speed Line
3 50.00 9.62 415.35 Speed Line
3 60.00 14.68 829.32 Speed End

I thought that with the air horn this part of the curve would be flat but it continues to fade.

I don't see the huge dip around 3500-4500 we did on the one test run from yesterday, but I also don't see the high rpm gain

from that run -- suggesting some data slurring from 2nd gear at the top end. This is why I wanted to see the 'blue' or 2nd

run, is first gear all the way to ~6200 rpm and we can see the complete hp curve with no chance that the shift to 2nd gear

is mixed in.

Comparison of without the air horn (green) and with the air horn (red / blue) on runs from different days.

[Texas Jim]

From the last chart... it looks like it runs better WITHOUT the airhorn...

[Bruce Nunnally]

Certainly no better with. I will shelf it for now as it gets in the way of jet swaps.

I still don't get the loud induction noise mentioned as a sign of proper 32/36 tuning. We may not have sufficient vacuum still? I need to log vacuum.

I would like to design a cold air system. The radiator fans run all the time and are unshrouded so that air washes the carb intake air. The radiator and fans are ripe for redo as well another day.

AFR was 12.5-12.8 on that run btw, so better than the 11.x I saw previous.

Going to try fitment on the stock corolla header next just in case it can be made to work. If not, will need to figure out a custom header solution.

Ordered intake gasket so it will take a few days before can try the offy intake.

[Texas Jim]

Probably a stupid question but...... have you had anyone sit in the car and mash the gas pedal to the floor, with the engine OFF of course, while you LOOK into the carb and actually SEE if the throttle plates are opening fully ???

Sometimes there can be a difference in what the gas pedal does and what it does when you work the linkage on the carb by hand.

"IF" it isn't opening fully when you mash the gas pedal, that could account for the LACK of intake noise.

[Bruce Nunnally]

Yes rechecked this with my son when I redid the linkage.

[Bruce Nunnally]

Got a start on trying to install the header. All 5 exhaust manifold bolts, and both exhaust pipe bolts came out no problem, and the exhaust manifold is off.

Looking down at the exhaust manifold when it was installed

the stock manifold feeds 1 and 4 into one pipe, and 2 and 3 into another then mixes

Shot of the mouth of the stock exhaust manifold

I suppose the pipe weld is where the cat was in the oem installation If the header can't fit for some reason I think taking this to the muffler shop and

having them re-do the lower (mid) section with continuous and perhaps larger diameter piping would be an improvement

No obvious port matching needed

New header waiting installation

engine compartment view since I have not shown it lately.

[Bruce Nunnally]

bonnet off and against the wall for full access

squeezing the header in - can't fit up from the bottom due to cyl 3 tube, can't fit down from the top due to steering rod

Pulling plug wires gave some room. Possible that pulling valve cover would give some room to angle, but if I could move steering shaft that seems best

Steering rod has this double knuckle affair; loosened the bolts on both ends but can't get it to slide up one side or down the other enough to free the rod end

I am hoping if free the rod end can move up and out of the way, and that if it were out of the way the header would slot in under it.

[Bruce Nunnally]

got the steering rod undone -- you have to take the bolt/nut completely off the collar to allow the keyed shaft to escape.

With the steering rod up and out of the way I could almost get the header down and into place -- but it hung on the bracket for the steering

Removed the bracket, and the header is in place with the felpro gasket and 4 of 5 bolts

Couple of issues:

• one of the header bolts is not going home properly -- won't start. Tried another bolt in that hole same issue, but it tightened in another hole. Possible the hole is sprung, or has something in it? Have to sort it out.
• 11" of space between the header 3-bolt flange and the exhaust pipe 2-bolt flange. This looks like a place for a 11" pipe with one of each flange on each end.

  

• the header sits slightly lower so I lost some ground clearance

  

• The header is too close to the steering bracket I mentioned. Either I will need to just recognize and put a high temp isolator in there, or bend the bracket away, or alter the bracket shape, or header pipe away or something.

[Texas Jim]

Bruce,

Try loosening the other 4 bolts, so that you can move the header around a little bit and see if the 5th bolt will then start.

If that fails... take the other 4 bolts completely out and try starting the 5th bolt.

If that fails, move the header back a little bit and try starting the bolt by itself... without going thru the header at all.

If it still doesn't work, it may take a tap to clean the threads up.