351w timing

[fast3175]

First off this is the first Ford "hotrod " I have ever owned and only bought it becuz the price was right. I have however owned many other hotrods over the years. I bought an 84 capri from a friend who spent alot of money building years ago and then let sit for 3 years. It was a 5.0 car now has a 351w.

Motor I believe came out of an LTD. It has kb hypereutectic pistons (part #Kb124) which show to be 11.5:1 w/55cc head and 9.7:1 w/69cc head. Heads are stock fully ported w/crane roller rockers. Cam is comp cams part #35-452-8 hydraulic roller 290/290 at .006 and .544"/.544". Victor Jr. intake and Holley 750dp with milled choke & 50cc pump in front. Hooker Super Comp (part #6223) 1 3/4" primary full lenght headers and 2 1/2" exhaust with Flowmasters that exit in fron of rear tires. Stock dist. and the duraspark are still in car. Built C-4 with 10" 2800-3200 conv and 9" with Detroit locker diff and 4.10s. Holley blue elec with crappy stock fuel line to reg. set at 6.5psi.

Now all that said, what kind of timing should I be running with this combo. When I bought it timing was at 17 on the balancer and I have no clue what is built into these things. Car had alot of bottom end but nosed around 5500. Prob alot to do with small stock fuel line but I backed off timing to 12 at the balancer and it pulled well to 6200. What kind of rpms are these things good for? Is the Duraspark junk or should I leave it in? The heads are the stock ported units which I have heard from friends are prob killing the motor. Any truth to that? How much diff. would I see with some Trick Flows or maybe AFRs?

I know a little windy but I hate having people have to ask me more questions before they can answer mine so I try to be thorough. Thanks in advance for any help.

[vristang]

Welcome to the Board!
Heads will make a huge improvement on that motor.
TrickFlow or AFR would be great.

I will let someone else answer the dist and timing Q's though.
Although I would think that if it runs better with less timing, you should be ok with the 12.

jason

[Rev]

I run 13 deg. initial timing with 38 deg. total advance, all in by 3000 rpm on my 306. I would get an aftermarket electronic distributor (my choice would be an MSD magnetic pick up - no vacuum advance). It would allow total advance adjustment of the mechanical advance mechanism. I think 6000-6500 rpm is all you want out of that combo probably less with those heads. Where does Comp Cams say the power peak is for that cam. I think those heads do probably hurt you some at those rpms. You may need better bottom end to run repeated high rpms above 6000. At least stronger rod bolts and maybe better rods might be necessary to hold it together. Good luck with the project and have fun with it.

Rev

[rwhite65]

The heads are definately a limiting factor for you. I dont know what size your stock fuel line is, but I would suspect it may be limiting you a little as well.
Ryan

[fast3175]

Thanks for the help guys. Sounds like heads will be my first change. Anyone know if I will have valve to piston probs with the Trick Flows? I have heard that becuz of the valve angle this is a pretty common issue and I dont wanna have to worry about it. I would prefer something I can bolt on and go. Thanks again.

[Rev]

TrickFlow TW heads are supposed to be OK with stock pistons up to about .500" valve lift. Anyone will tell you though to check piston to valve clearance when you install just to be 100% sure that you won't smack a valve the first time you really wind it up.

I'd bet those KB pistons are fly cut as well and that would help even more on the piston valve clearance. With .544" lift and 290 deg duration, I think you should be very careful to make certain that you do have adequate piston valve clearance before you fire it up with the new heads.

Rev