Mopar Muscle Association UK

Just got in after picking up this holley 750 i won on ebay last night.
It was only about 5 miles from my house so no postage or waiting.
I had to borrow the ?185 quid though!
It was described as only having two weeks use and is the same model number as the crusty one i took off.
It came off a 360 Mopar so can anybody tell me if i'll have to rejet for my 440?
Did i pay the right price or was i robbed?

:pirate:

Edit: Pic now attached

I think you will almost definately need to rejet for a 440

I'd remake that pipe to get rid of the rubber.

Kev wrote:I'd remake that pipe to get rid of the rubber.

Will do then.

Ta Kev.

Bratfink wrote:I think you will almost definately need to rejet for a 440

You assume it was right for the 360. I think it will work OK too.

Outta the box jetting should suit a 440 , but it might have been jetted down for the 360.

Odds are it wasn't though.

Ok, what jets should be in there or what should he use if they have been changed

Jetting depends on the engine and what you want from it. Engines are as individual as people. I am always banging on about it. Haven't you noticed?

I would fit the carb as it is and install a rich/lean indicator (best) or a vacuum gauge (second best) to tune it.

Always check fuel level in the bowls after any jet changes. Set your idle mixture and speed first.

Vacuum gauge is the cheaper route. Just disable the secondaries first so you are only testing the primaries. Pick a stretch of road you know well and drive along it at two different rpms (best) or one rpm (3000rpm) noting the exact vacuum reading each time. Use the same stretch of road for each test.

Then go up two jet sizes. There is not enough difference between one jet size and the next to make a readable difference so always move up or down two sizes at a time unless you are fine tuning.

Repeat your tests. Do one of the following.

a) If vacuum is higher try going up another two sizes. Repeat tests until vacuum stops rising. Your correct jet size is the size you used the last time you noted any increase at all.

b) If vacuum is the same or lower after going up in jet size go down the jet sizes until you find where the peak vacuum level is.

With a rich lean indicator you can see all the time what your mixture is.

Keep an eye on your plug colour after all this.

Thanks to all replier's (is that a word?) respondee's, answerer's?
A rich/lean indicator sounds expensive, I could do with a vac gauge at work anyway so this is probably the way i'll go.
Don't know if i'll rig a cable choke or take it off altogether as has been sugested by members.
Looks like i either have my fuel pressure gauge and my rubber joint or neither so gonna try it with for now.
By disabling the secondaries i asume you mean keeping them in the shut position right?
Do the secondaries not have jets too?
I have skimmed over the recent "how to...." threads, i'll have to read them more throughly.
How in the dark would i be without this board?
In total darkness thats how dark.
Once again, Thanks

wildman wrote:By disabling the secondaries i asume you mean keeping them in the shut position right?

Right.

Do the secondaries not have jets too?

Jets or a plate with holes. Yours has a plate i think. Secondaries are a bit more tricky to get right. You can only drill bigger. Bummer if you go too far because you will have to buy a new plate and they are pricey. Just work on the primaries for now. You do 95% of your driving on those. When you feel like you know what you are doing give the secondaries a go later on.

My 600 Vac Sec has a replacement secondary plate that is jet changeable. They are well priced (minus jets) and come with a longer transfer pipe with good seals. Can't remember the price but it was worth it to have that tuneable factor.