Can you assist me in geting better ¼ mile performance while keeping my Comet a streetable car?

Same box I am using to trigger my Duraspark dizzy. Have not installed the engine yet, but am looking forward to exploiting the ability to run a lot of lead when cruising and enjoying the MPG.

 

You could always just put a straight six and turbo it out and have one high torqued six banger.

 

One thing to watch for is at wide open throttle,if your mtr has 10& 1/2 or less comp ratio,there is no need to have more than 32 degrees of total advance because you are not going to make any more HP.Over the yrs there has been many dyno tests on a number of different engines & this has been proven.Also ,high timing & a lean condition if you don`t catch it will burn a piston quickly.Groberts can give you some ideas on how to avoid this.

 

There are some generalities in timing advance requirements at peak power/WOT but really are no steadfast rules, Dan.

Much of it has to do with cumbustion chamber design and even the amount of swirl or tumble caused by the port angle/design itself can play a part in mixture homogeniety. Some of the old iron can run very high lead at WOT because the chambers are crap.. whereas the newer designs are much more efficient and can run as low as high 20's - low 30's. Compression ratio has a lot to do with it but the camshaft can play a huge role here because it decides where the cylinder pressure peaks occur.

Also consider that highly tuned intake tract size/tapers/lengths and properly sized exhaust systems can play big roles based on their contributions to inertial ramming(fresh charge push) and scavenging(spent exhaust gas pull). And when you get even one or both of those wrong?.. which many do.. things that go boom really start to get all confusing. What advance curve or total timing number works for one combo of somewhat similar parts.. just can't be matched on another when even just a few things have been changed up.

As for how to avoid burn down?.. well.. don't lean it out looking for that last 2 or 3 horsepower and stay on the safer side of the fuel curve. Which brings up another conundrum. What is the proper A/F ratio for max power? Some love 12.5'ish.. others can run upwards of 13.xx+. All of the previously mentioned things can and do come into play there too. Even vehicle weight and drivetrain/chassis setups have impact here too. Rich is always safer than lean and keep in mind that a blown up engine always makes MUCH less power than any pig rich motor ever will. Unless the motor is squeezed or running nitrous.. too much ignition lead is far better than running too lean on fuel since it will just cause the motor to lay down a bit and fall over faster after the peak as more fuel remains unburned and the peak cylinder pressures are reduced. MBT falls, efficiency, and power is lost.. not the end of the world. Which allows us to take the hint without severe penalty and move back in the other direction to regain what was lost because we got too greedy with total timing.

 

Yeah Rob,we both know a heavy car that is lean,the mtr is not going to last very long.I am a plug reader myself as I am not familiar with the new technology.At the circle trk. yrs. ago,we always shot for a light chocolate brown color on the plug.However,some of the tuners on the late model stock cars would lean them down where there was almost no color at all,squeezing out every ounce of HP they could.Just through trial & error you had to find out how far you could push it,of course this will get expensive when you gall a piston.It will take me awhile to get up to speed on the newer stuff when I get to the trk,just have to keep learning.

 

with high energy msd ignitions plug reading are a different world of the old school light brown color. reading a fresh plug entails looking at the brown ring around the porcelain and how far up or down it is. and for timing, I agree that timing really has to do with chamber design and piston. I run a wiseco dome piston in my Boss 302 and with the closed chamber head it runs best at 45 degrees. full timing comes in at 2000 rpm. the only reason I dont lock the timing is for a little ease of starting. I run a Ford Duraspark Dist which I feel is a very easy distributor to set up and its very reliable. I run it with an msd 7AL. new aluminum heads with small heart shaped chambers and small or no dome pistons run around 32 degrees. and they make no more power above that. even the ford race manual in 1970 was telling you to run 42 degrees on all their engines back in the day.

 

What brand of heads are you running on the Boss?

 

Original Ford heads

 

I`m not the only one,but most people I know don`t bother going over 40 degrees of timing unless they are pushing over 11to 1 compression,there is just no gain in power to be had & I`m not going to argue w/ them.

 

It's actually the other way around most times, Dan. Lower compression ratios can and need higher total lead as the mixture motion and combustion speeds are reduced. Mixtures start to pop off pretty quickly well over 12 or 13:1 ratios.

On the other hand.. and along the lines of the old iron being currently discussed now.. there are some pro-stock racers out there turning near 10,000 rpm and using 43 degrees of spark lead. This is one of them.

 

Wouldn't that be a stock or super/stock Mustang? I hate to join in and add to the arguments but my understanding is the timing is generally dictated by cumbustion chamber size and shape. Older stuff generally had to have more timing and if you start doing weird stuff like dome pistons it adds more complexity. But, with most flat top or stock style pistons and a modern combustion chamber design Total timing will be lower. My world products heads with flat tops runs best around 32-34* iv tried 36-38 and it makes no difference. So, I always ran the lowest total that it would run. Just my experience.

 

Yes I am talking mainly about the iron headed stuff,& that is what I`ll be using for a while with the Roush hds.I know they are`nt the best but hopefully w/ bigger valves & the port work done at a .600 lift if I get 280 & 180 they will be decent.Iron does have one advantage over aluminum,they hold heat,& heat is HP.

 

This is my response to the first post from Krazy Comet at the beginning of this thread. KC, you were the first with the right solution for my getting into the 12s. I didn't get to the track as much this summer, other things just continued to take priority. I played around running BFG Radial TAs in place of the M/T Drag Radials. It turned out to be a big mistake. The Comet got real slow and dangerous. I almost headed her into the wall twice about 100 feet out from the staging lights. It was ugly!!!!!!!

Yesterday I went back to the M/T Drag Radials after installing a 3,500 convertor. I was running a 2,400 stall convertor. The Comet immediately responded. I went from a best with drag radials of 13.02 at 108 to a 12.53 at 109 with no other modifications. Happy dance!!!

I want to thank everyone for their input!!!!! This is the best site for Maverick and Comet owners.

 

Congrats on the new time!!!

 

An already impressive car picks up six or 7 tenths from a converter