Rob & Stu's 63 Polara 500
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BUDGIE
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Anonymous
I hope it goes well.
Someone was telling me (from New Zealand) about these mobile chassis dynos where you take your rear wheels off and the dyno bolts to the hubs. It seems there are several that go to events over there. Never heard of that before.
I saw one of the big US mobile dynos at the Buick GS Nats some years ago that looks like a car transporter with the car at head height. Quite scary, I thought, especially with the turbo cars where you never quite know what is going to happen
Keen to see the figures
Someone was telling me (from New Zealand) about these mobile chassis dynos where you take your rear wheels off and the dyno bolts to the hubs. It seems there are several that go to events over there. Never heard of that before.
I saw one of the big US mobile dynos at the Buick GS Nats some years ago that looks like a car transporter with the car at head height. Quite scary, I thought, especially with the turbo cars where you never quite know what is going to happen
Keen to see the figures
there y'go Sandy, pic halfway down page....DynopackSandy wrote:Someone was telling me (from New Zealand) about these mobile chassis dynos where you take your rear wheels off and the dyno bolts to the hubs. It seems there are several that go to events over there. Never heard of that before.
http://www.mopartalk.co.uk/mopartalk/vi ... c&start=15
Gavin Chisholm - 414ci W2 Stroker SmallBlock Panther Pink '71 Challenger convertible - in bits
Car progress can be viewed here
Car progress can be viewed here
Thanks for your patience guys, thought I'd jot down a line or two about how the 'dyno day' went...
Got back home about midnite on Friday after a day of mixed fortunes up at Engine Data Analysis.
Arrived there bright 'n' early at 9am with the plan of breaking the old, but fresh girl in, then seeing how we get on with some carb tuning and some different combinations of more timing and more octane. Well, we all know about best laid plans.......
Once Dave & Bill Billadeau had brought back Kenny's flywheel
, Dennis of EDA & Paul Knight got on with coupling us up to the dyno ready for phase 1 (break-in)
This gave us plenty of time for some Mopar chit chat with Dave & Bill while Paul & Dennis got on with the work!
After they'd attached the headers, fuel supply (super unleaded), coil, water pump hoses, sensors for this and sensors for that, and chucked in some 20/50 we were ready rock n roll
As the first goal was to successfully break in the cam, Dennis fired her up and kept it at 2000-2200 rpm for about 30-40 mins. Phase 1 completed successfully, to everyone's relief . The only suprise was that it used 4 gallons in that time, and by my CSE-grade1-maths-reckoning, that equates to about 8mpg Not too bad on a run if out on the road, but at a constant 2100rpm?!
The problems (yes, problems - what did you expect?!) came when we started to put it under load and give it a few more revs. There appeared to be a big flat spot (engine almost stalled) as the revs rose above about 2500, and the dyno indicated this by showing it was running lean each time we got the flat spot.
After a couple hours checking the float levels, changing some springs & needle/metering rods, and making sure the secondaries were opening, we still hadnt got to the bottom of it
To cut a (12 hour day, and a) long story short(ish), after investigating other areas, Kenny & Paul then noticed that it was the primaries that weren't squirting consistently each time the throttle was applied. Although this was 95% (Kenny's estimate) definitely all that was causing the lean spot, we wanted to fit another pair of carbs to see if it cured the problem so we could be sure it was our 43 yr old carbs at fault, and nothing to do with the engine rebuild itself. Trouble is, EDA didnt have 1 carb that fitted our inlet, let alone a matched pair. He had an Edelbrock (modern version of our Carter AFB), but the linkage fouled on the inlet. As did all the Holleys.
One symptom that suggested it may not be just a carb problem, was that there were some soot marks appearing around the air bleed holes on one of the carbs, which Dennis thought might be something to with the high vol oil pump fitted. Den said you shouldn't use a high vol oil pump with a hydraulic cam (tho Paul, Kenny & Koffel that sold the pump said it should be ok), and as the pressure was over 80 psi at less than 3000rpm, thought oil may be pumping up (sorry if thats the wrong term!) the lifters and causing the valves to let the spent gases back thru the inlet and back thru the carb. To see if the high pressure was causing the flat/lean spot, we changed the oil pump spring for a weaker one. This dropped the psi down by about 30 on the next run but didnt eliminate the flat spot, so swapped the spring back and set about thinking what to do with the carb/inlet problem
As we werent going to get any of EPA's carbs on our inlet we decided to fit a single 4bbl inlet & single carb, just see if the flat spot went away. By this time it was getting on for 5pm. Time for the Billydoos to come to the rescue again!!
We got on the phone to Dave to see if he had a spare inlet that would fit, and that we could borrow for the test. Of course he came up trumps so we high tailed it over to Bradford in Paul's Previa as quick as the rush-hour traffic would allow. Once there, all he could offer
was an Indy single plane manifold (should do nicely!), and also gave us an Indy valley cover plate as our cross-ram covers the valley without separate cover/gasket. Oh, and a couple of stock oil pumps in case the pressure needed looking at again!
I know the Billadeauxs do work with Kenny fairly regularly, but we'd never really spoken before so we were extremely grateful to Dave for the loan of the parts. Cheers if you're looking in Dave
, we owe ya.
Back at Kenny's we found that the valley cover plate wouldnt fit with our heads and the Indy manifold so took a leaf out of Messrs Heath & Robinson's book and lashed up a valley pan gasket with a sheet of scrap ally and some duck tape (see pic) We figured it only had to hold long enough to do one pull on the dyno to see if the flat spot had gone with the removal of the 2x Carters, so RTV'd & DT'd it into place, bolted down the inlet, attached one of Kenny's 750 Holleys, reconnected the fuel inlet etc etc and settled down 
for a quick blast with some decent revs.
I'll pause there, attach some pics, then write up the next stage
about how the 'dyno day' went...Got back home about midnite on Friday after a day of mixed fortunes up at Engine Data Analysis.
Arrived there bright 'n' early at 9am with the plan of breaking the old, but fresh girl in, then seeing how we get on with some carb tuning and some different combinations of more timing and more octane. Well, we all know about best laid plans.......
Once Dave & Bill Billadeau had brought back Kenny's flywheel
, Dennis of EDA & Paul Knight got on with coupling us up to the dyno ready for phase 1 (break-in) This gave us plenty of time for some Mopar chit chat with Dave & Bill while Paul & Dennis got on with the work!
After they'd attached the headers, fuel supply (super unleaded), coil, water pump hoses, sensors for this and sensors for that, and chucked in some 20/50 we were ready rock n roll
As the first goal was to successfully break in the cam, Dennis fired her up and kept it at 2000-2200 rpm for about 30-40 mins. Phase 1 completed successfully, to everyone's relief . The only suprise was that it used 4 gallons in that time, and by my CSE-grade1-maths-reckoning, that equates to about 8mpg
Not too bad on a run if out on the road, but at a constant 2100rpm?!The problems (yes, problems - what did you expect?!) came when we started to put it under load and give it a few more revs. There appeared to be a big flat spot (engine almost stalled) as the revs rose above about 2500, and the dyno indicated this by showing it was running lean each time we got the flat spot.
After a couple hours checking the float levels, changing some springs & needle/metering rods, and making sure the secondaries were opening, we still hadnt got to the bottom of it
To cut a (12 hour day, and a) long story short(ish), after investigating other areas, Kenny & Paul then noticed that it was the primaries that weren't squirting consistently each time the throttle was applied. Although this was 95% (Kenny's estimate) definitely all that was causing the lean spot, we wanted to fit another pair of carbs to see if it cured the problem so we could be sure it was our 43 yr old carbs at fault, and nothing to do with the engine rebuild itself. Trouble is, EDA didnt have 1 carb that fitted our inlet, let alone a matched pair. He had an Edelbrock (modern version of our Carter AFB), but the linkage fouled on the inlet. As did all the Holleys.
One symptom that suggested it may not be just a carb problem, was that there were some soot marks appearing around the air bleed holes on one of the carbs, which Dennis thought might be something to with the high vol oil pump fitted. Den said you shouldn't use a high vol oil pump with a hydraulic cam (tho Paul, Kenny & Koffel that sold the pump said it should be ok), and as the pressure was over 80 psi at less than 3000rpm, thought oil may be pumping up (sorry if thats the wrong term!) the lifters and causing the valves to let the spent gases back thru the inlet and back thru the carb. To see if the high pressure was causing the flat/lean spot, we changed the oil pump spring for a weaker one. This dropped the psi down by about 30 on the next run but didnt eliminate the flat spot, so swapped the spring back and set about thinking what to do with the carb/inlet problem
As we werent going to get any of EPA's carbs on our inlet we decided to fit a single 4bbl inlet & single carb, just see if the flat spot went away. By this time it was getting on for 5pm. Time for the Billydoos to come to the rescue again!!
We got on the phone to Dave to see if he had a spare inlet that would fit, and that we could borrow for the test. Of course he came up trumps so we high tailed it over to Bradford in Paul's Previa as quick as the rush-hour traffic would allow. Once there, all he could offer
was an Indy single plane manifold (should do nicely!), and also gave us an Indy valley cover plate as our cross-ram covers the valley without separate cover/gasket. Oh, and a couple of stock oil pumps in case the pressure needed looking at again!I know the Billadeauxs do work with Kenny fairly regularly, but we'd never really spoken before so we were extremely grateful to Dave for the loan of the parts. Cheers if you're looking in Dave
, we owe ya.Back at Kenny's we found that the valley cover plate wouldnt fit with our heads and the Indy manifold
so took a leaf out of Messrs Heath & Robinson's book and lashed up a valley pan gasket with a sheet of scrap ally and some duck tape (see pic) We figured it only had to hold long enough to do one pull on the dyno to see if the flat spot had gone with the removal of the 2x Carters, so RTV'd & DT'd it into place, bolted down the inlet, attached one of Kenny's 750 Holleys, reconnected the fuel inlet etc etc and settled down for a quick blast with some decent revs.I'll pause there, attach some pics, then write up the next stage
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Anonymous