any ideas?

[Anonymous]

hey i just finished all my engine work for now... but i was wondering...
1967 mustang
the car was stock untill i put a 264 cam 110*, 1.6HR rocker, 2bbl holley 500cfm, new springs and push rods (the whole extended cam package) and a y-pipe to 2.25" dual exhaust.
im now getting anywhere from 10-15mpg before i was getting 18mpg
the car defently runs better than before but the car still doesnt seem fast enough... i know i know its never fast enough but still.
does anyone have any ideas on how to get more power out of these things without going to a turbo or supercharger. i want raw/naturaly asperated power. thanks!

-Sean

 

[Anonymous]

would a MSD 6AL do anything?

 

[yodabiri]

I would probably start with a header. That would allow the car to get rid of exhaust gasses faster, and it would definitely increase the power output, probably not by much but it should be noticeable. Plus since you have a 500cfm carb, the difference should be much more noticeable. Also you might get a few mpg back ; )

 

[Inline6Merc]

Also a good dizzy. Such as the Duraspark or DUI.

later,

Curtis

 

[wsa111]

Sean, are you ready?

You need a distributor with mechanical & vacuum advance, such as a ford duraspark, or better yet get the new DUI distributor from FSPP.

Second you need a 77 and above cylinder head with a direct mount for your 500 carb, by the way if you just bolted on the 4412-500 carb with the stock jetting, that is part of your lost fuel miliage.

Better yet is an aussi or argie cylinder head or the yet to be marketed head from FSPP.

Third you need a good header for a decent exhaust.

Get out your checkbook. William

 

[rbohm]

8) as stated if you have the stock jetting, you need to lean the fuel mixture out. in fact you might pick up as much as 25hp by getting your fuel mixture just right. a header will also help in both power and fuel economy.

 

[CZLN6]

Howdy Sean:

Hang in there. May I ask a few questions to maybe help with responses? What is your at idle and driving around vacuum like? How did you mount the #4412 Holley two barrel? Adapter or direct? What trans and rear gear do you have?

My guess, from what you've reported is that the Holley is way too rich for your application. And, depending on your engines vacuum the stock Power Valve may be set too low and the channels too rich. William has done alot of work with an Air/fuel meter to fine tune this application. Your new cam and package has likely reduced your idle vacuum.

The 264 cam package may be too much for your stock '67 head, or any log head for that matter. The cam shows .450" lift with a 1.5:1 rocker ratio, you got the 1.6:1 rockers, which increases lift even more. A stock '67 head is not capable of utilizing anymore than about .400" of lift. That cam really needs a optimized late model head at the very least, or better yet, as Bill suggested an Oz 2V, an Argie, or the new FSPP aluminum head.

Clearly the stock '67 Load-a-Matic distributor is not compatible with the Holley and not the best for performance or economy. Either the DS II or the DUI, with ported vacuum and centrifugal advance, would help a bunch.

A header will also help, but again, flow in or out, will depend heavily on the head ports.

Finally, your trans and rear gear are part of the final package. The cam you chose will hurt low rpm performance unless compensated for by adding more compression, initial advance and deeper gears. If you have a C4 trans you may have to do some adjusting on the vacuum modulator to compliment the lowered engine vacuum.

The strength of your cam and package is at the higher rpm range, but the rest of the engine isn't.

Your engine/vehicle package, is out of balance. You basically have a stock engine with a performance cam package. The rest of the package has to be upgraded to complement the potential of the cam package.

Start by increasing initial advance as much as you can short of pinging. Check out some of WSA11/Williams posts on tuning the #4412 for this applications.

Be sure to reply with more details on your total package.

Hope this is helpful. Be sure to enjoy the journey.

Adios, David

 

[Anonymous]

dont give up...tune up!!!

 

[addo]

I don't pick fault with the cam installation itself, but have a few questions and comments:

With a stock exhaust the carb is too much. You will have very similar performance with the stock carby, until near the RPM ceiling. There is a possible risk of bore washing with the excess carburetion.

I also would ask if the cam was correctly dialled in by the installer, and TDC verified. Yes, I am a skeptic about what happens when you turn your back on many mechanics.

Further to that, was the CR calculated and matched to the recommended amount, for this cam? No matter on the carb or valve timing, this is critical.

Then the distributor curve needs to be mapped, and modified as needed. Even the rebuilt dual advance points units have been proven to come with the wrong advance setups.

Cheers, Adam.

 

[Anonymous]

the carb was put on with an adapter
the trany is the stock c4 with original rear and gears
im not sure i told the mechanic to dial the cam in but im not sure i will check with him tomorrow (i've known him for 7 years)
what is the "CR"?
im plaining this weekend to re-gap the points and to check and re-set/advance the timing.

the car defently has more power it just feels like it has more in it on the low end its better but one you get to the higher end it picks up. also it feels like it shifts too soon when you have it floored.
any more ideas or sugests or questions let me know

 

[JackFish]

Was the head milled? Was the removed gasket steel?
When you say "faster", do you mean higher top-end, or getting up to high rpm quicker?

 

[Anonymous]

acceleration and high end speed were both improved nothing was milled

anyone have any ideas on how to make the intake manifold able to breath better or find one that will bolt up and allowe for a 500cfm holley

 

[JackFish]

acceleration and high end speed were both improved nothing was milled

I want to know if you want a higher top-end, OR do you want to get there faster?
If your gasket was replaced without milling then you probably have a low compression ratio (CR), due to the thicker composite gasket versus the thin original steel shim. Because there's more space in the combustion chamber, the gas doesn't reach a high enough compression to create maximum power when ignited.

 

[mcmillal]

Hi Sean,

I would definitely agree with the header and distributor recommendations. I too have an adapter mounted Holley 500cfm carb that runs awesome. I have not seen any hardened proof showing significant gains between a direct mounted carb vs adapter mounted. However, I did enlarge the intake opening equally on the adapter and intake log by about 40%. This gives me a bit more breathability. I also had quite a bit of work done honing out the inside of the intake log. What I think is really helping my setup is the height of the carb above the intake due to the adapter. Is helps to atomize the fuel intake better. I have great performance at both the low and high ends.

I will definitely be playing with some of the ideas William has suggested, on this forum, for tuning these 500cfm carbs.

Just another point of view.

............Cheers, Alex

 

[Anonymous]

for Jackfish... i want acceleration... so basically i want to get there faster!
im working on this to eventualy take to the drag strip[/quote]

 

[Anonymous]

on the distributor what years would a ford duraspark or duraspark 2 work for a 67 200 I6??

and for mcmillal what did you use to grind/bore out the adapters?

 

[rbohm]

8) ford put the duraspark on 200's and 250's starting in 1975(iirc) and they ran through the end of 200 production in 1983.

 

[JackFish]

for Jackfish... i want acceleration... so basically i want to get there faster!
im working on this to eventualy take to the drag strip

[/quote]
What rear gear are you running, and what's the initial timing set to?
The double roller timing chain, if you don't have one already would be an excellent bolt-in. You could advance it up to 6* for some healthy grunt.

 

[mcmillal]

Sean, I had the head work done for me, but I believe the guy used a dremel type of tool to enlarge the intake and adapter.

.....Cheers, Alex

 

[Anonymous]

as far as i know they are the stock rear gears... though i sat and burned my tires for a friend and i had both lose and spinning. i already have the double roller chain... im not sure what the timing is set to i was planing on playing with the timing this weekend...
im really thinking of doing the duraspark swap... any clues? besides the write ups in the tech info