Mopar Muscle Association UK

Pete wrote:More cammage, chap

Mine being bigger, or Blue needing more.
Mick

I think more over lap would help Blue's out, but I know he is trying to compromise on road useage....I think a cam swap is easier and cheaper than a tear down....you pays your money...........

Blue wrote:I'm sure that if I was working with a conventional six pack manifold I would have had it cracked ages ago. Trying to tame a race manifold with a huge plenum is the challenge.

I quite agree.

will be nice to meet up and say hello to all you modern Mopar Racers and streeters ...will no doubt bring back some good old memories for me.

See you there Sat 30th .......Les

Dave wrote:

Blue wrote:I'm sure that if I was working with a conventional six pack manifold I would have had it cracked ages ago. Trying to tame a race manifold with a huge plenum is the challenge.

I quite agree.

http://www.aussiespeed.com/index.php?pa ... &Itemid=23

Errmm might work

youd have to drill and tap the base of the manifold and stick a helicoil in
and i guess if the plenum is really big you'd need 2 or 3



Ok....i'll get me coat


Dave

Not silly at all Dave. Although that design wouldn't fit the manifold in question.

In fact that reminded me that I once considered running one of those manifolds on my car but if I had done so I was going to try dividing the manifold in half length-ways so that each cylinder only "sees" half of each carb. That would double the vacuum signal to each venturi and probably solve the issues Blue and Jem are having.

I have been thinking about ways of reducing the plenum volume, there are some less than elegant attempts at the bottom of this page,
http://victorylibrary.com/mopar/weiand-c.htm

Dividing the manifold down the middle is an interesting idea Dave, I'll have to have a closer look at the position of the carbs to see if I agree with you on that one.

Blue wrote: Dividing the manifold down the middle is an interesting idea Dave, I'll have to have a closer look at the position of the carbs to see if I agree with you on that one.

Not having one of the manifolds to hand I never looked into the practicalities of doing this.

I do know that Mopar Action once opened up a standard aluminum dual plane manifold plenum just to see how well that would work on a 500 inch big block test mule as part of an overall manifold comparison test.

The results were terrible.

Yet the unmodified standard manifold stood up very well to several popular single planes.

I just feel that the six pack works best with a strong vacuum signal and high velocity through the carbs. An open plenum at low-to-moderate revs just does not flow enough through each venturi.

Dave wrote:

Blue wrote: Dividing the manifold down the middle is an interesting idea Dave, I'll have to have a closer look at the position of the carbs to see if I agree with you on that one.

Not having one of the manifolds to hand I never looked into the practicalities of doing this.

I do know that Mopar Action once opened up a standard aluminum dual plane manifold plenum just to see how well that would work on a 500 inch big block test mule as part of an overall manifold comparison test.

The results were terrible.

Yet the unmodified standard manifold stood up very well to several popular single planes.

I just feel that the six pack works best with a strong vacuum signal and high velocity through the carbs. An open plenum at low-to-moderate revs just does not flow enough through each venturi.

dave are you going the nats if so are you racing the vette/ what et do you expect

Cannonball wrote:[dave are you going the nats if so are you racing the vette/ what et do you expect

A nice quiet quarter mile drive in air conditioned comfort.

But high 13s would be nice. Surprising but nice.

For Christmas I am going to get one of those code reader/Programmer things.

The idea next year is to get some baseline runs in and then upload a "performance" profile to see how much (if any) difference they really make.
Then re-program it to either "economy" or "standard" (if there is a difference) for the drive home.

But for now I am more than happy with the way it drives and have no immediate plans to change anything. However it uses so little fuel I could afford to upgrade the performance settings slightly at the expense of mileage sometime in the future.

See you on the Sunday at the Nats. I will stop by to say Hi.

Dave wrote:

Cannonball wrote:[dave are you going the nats if so are you racing the vette/ what et do you expect

A nice quiet quarter mile drive in air conditioned comfort.

But high 13s would be nice. Surprising but nice.

For Christmas I am going to get one of those code reader/Programmer things.

The idea next year is to get some baseline runs in and then upload a "performance" profile to see how much (if any) difference they really make.
Then re-program it to either "economy" or "standard" (if there is a difference) for the drive home.

But for now I am more than happy with the way it drives and have no immediate plans to change anything. However it uses so little fuel I could afford to upgrade the performance settings slightly at the expense of mileage sometime in the future.

See you on the Sunday at the Nats. I will stop by to say Hi.

nice one, see ya then

Dave wrote:

Blue wrote: Dividing the manifold down the middle is an interesting idea Dave, I'll have to have a closer look at the position of the carbs to see if I agree with you on that one.

Not having one of the manifolds to hand I never looked into the practicalities of doing this.

I do know that Mopar Action once opened up a standard aluminum dual plane manifold plenum just to see how well that would work on a 500 inch big block test mule as part of an overall manifold comparison test.

The results were terrible.

Yet the unmodified standard manifold stood up very well to several popular single planes.

I just feel that the six pack works best with a strong vacuum signal and high velocity through the carbs. An open plenum at low-to-moderate revs just does not flow enough through each venturi.

single plane manifolds running spread bore carbs on aussie hemis
gives a dough like off idle reponse and often a big flat spot when the secondaries open.

usual method is to turn carb around 90*

and divide plenum with a welded in ally plate
that has a 1/8 of an inch deep 1/2 inch long section missing out oif the top edge directly under the centre of the carb

front 3 cylinders have 1 little and 1 big
back three cylinder have 1 little and 1 big

with the option to tune it by putting the secondaries closer or further away from the port buy turning it round

driver has grin
tyres have no tread

you run a 650 on a 265 Inch engine....!

less of an issue with a smaller squre bore for obvious reasons but similar torque impact when divided.

sure you don't fancy 4 52mm JayCee IDAs

you can have an 8 pack then

Dave