my '69 Plymouth

A place to show off your Pride and Joy

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hemi472
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Post by hemi472 »

Great looking car :thumbright:

i dont know if there are any six pack tuning experts on here - but i would i thought you could change the power valves ( i guess the outboard carbs have a power valve?) and put a lighter spring in the diaphragm ?
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Pete
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Post by Pete »

No power valves or enrichment devices in the outboards and that is the set up's Achilles heel.

You get the legendary "Stumble" as you have just opened up 2 x 500 cfm carbs and not added any fuel with them.

The engine soon overcomes this, but it is always noticeable if you floor it hard.
Pete Wiseman; Cambridge.

Mopar by the grace of God
JinxJay
Posts: 254
Joined: Thu Jun 05, 14 12:17 pm

Post by JinxJay »

hey folks, thanks again for the positive comments. well i've done the cam and the car is much better,
even on these very cold mornings ,two stabs of the throttle and it fires up straight away and ticks over on its own,
set the six pack and kickdown up as stock, it runs and drives great, have an air leak on the rear carb , but will sort that soon,
now its not a multi feet dance to stop, having to blip the throttle to stop it from stalling while slowing down in neutral .
the brakes could be better, but now i've 17 inches of vacuum at idle instead of 4.5 I can put power brakes on,
that's next weeks project, need a bit of heat in my garage first,,

also have to sort out the colour of my engine, had the correct shade mixed for the valley gasket and new rocker boxes, but completely the wrong colour for the rest of the engine, oh well something else to deal with,
JinxJay
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Post by JinxJay »

hemi472 wrote:Great looking car :thumbright:

i dont know if there are any six pack tuning experts on here - but i would i thought you could change the power valves ( i guess the outboard carbs have a power valve?) and put a lighter spring in the diaphragm ?
the middle carb does all the normal work, but its basically an eco-carb and does not like low vacuum

there are ways round it with different base plates etc, but to be honest it was not fun round town and did about 3 to the gallon!!!!
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Charger
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Post by Charger »

it sounds fantastic now as well 8-)

:thumbright:
Si
1970 Charger 500
383 | 4bbl | 727 column | PAS | PAB | buckets/buddy - check out my photos HERE

If you don't want another same old brand-new car ... you could be DODGE MATERIAL

1970 Dodge Charger Registry - https://www.1970chargerregistry.com/
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Jim
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Post by Jim »

Pete wrote:No power valves or enrichment devices in the outboards and that is the set up's Achilles heel.

You get the legendary "Stumble" as you have just opened up 2 x 500 cfm carbs and not added any fuel with them.

The engine soon overcomes this, but it is always noticeable if you floor it hard.
That's part of the charm of a Six-Pack Pete. The little 'stumble' then it's like getting hit around the head with a baseball bat. It's fabulous, it's what makes the Six-Pack special, - more exiting sometimes than flooring the more progressive 2 x 4's on a Hemi.
Last edited by Jim on Thu Nov 10, 16 9:27 am, edited 1 time in total.
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Blue
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Post by Blue »

Yea six pack set up's are just a poor design, I guess it was down to cost. if the outboards had accellerator pumps and the carbs were canted or mounted sideways it could have been a tuners dream, rather than the compromise it is.
“This ain’t no party, this ain’t no disco, this ain’t no foolin’ around”
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octanejunkie
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Location: Somerset

Post by octanejunkie »

Sweet looking car. Very menacing. :drwho:
"If its a job no man can survive, he's the man for the job"
JinxJay
Posts: 254
Joined: Thu Jun 05, 14 12:17 pm

Post by JinxJay »

been meaning to add a few more pics...

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Sandy
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Post by Sandy »

Is DaveR not around any more?

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I don't remember the Challenger having any stumble.
Dodge This, Cat That

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Blue
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Post by Blue »

Dave isn't a member these days Sandy. His carbs were heavily modified in the States, very skilled work. I did look to replicate the modifications when I was tuning Jems Belvedere but decided I had neither the equipment nor the watchmaker level of skill required.
“This ain’t no party, this ain’t no disco, this ain’t no foolin’ around”
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Sandy
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Location: Glasgow

Post by Sandy »

Hi Blue,

I didn't realise Dave wasn't a member any more.

Yes, Linda took the carbs and manifold across to the U.S. on a plane and brought them back on her return after the work had been done.

The Challenger did go well (not as well as a V6 Buick of course, but not bad for a Mopar ;) )

All the best
Sandy
Dodge This, Cat That

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JinxJay
Posts: 254
Joined: Thu Jun 05, 14 12:17 pm

Post by JinxJay »

hi folks,

finally got round to fitting the new servo, master cylinder and bias valve, my car at some stage it had been fitted with discs on the front but still had the original drum / drum bias valve, but had been updated with a disc / drum manual master cylinder.

the brakes were never great , in fact my old roadrunner with drums all round stopped better ... LOL

anyway I did my research and found the bias valve of a '78 Cordoba had all the correct fittings to suit my car that had a drum / drum bias valve, it fitted with little problem, other than the headers being a pain in the arse to work round,

the master cylinder / servo combo fitted very well with new firewall gaskets etc, had the correct rod and fittings and was adjusted perfectly to drop straight in, just had to make the lines from bias valve to master cylinder,

a very straight forward job after bleeding, and checking the adjustment on the rear shoes,

I cant believe how much of a difference it has made, the car now drives more like a modern car, very little effort needed to stop, and has made it more of a joy to drive,


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Charger
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Location: Manchester, UK MMA/921

Post by Charger »

nice one Jay :thumbright:
Si
1970 Charger 500
383 | 4bbl | 727 column | PAS | PAB | buckets/buddy - check out my photos HERE

If you don't want another same old brand-new car ... you could be DODGE MATERIAL

1970 Dodge Charger Registry - https://www.1970chargerregistry.com/
JinxJay
Posts: 254
Joined: Thu Jun 05, 14 12:17 pm

Post by JinxJay »

heres a few under side pics..

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