Cam and Head

[70stangcoupe]

Ive recently decided to start doing some performance modificatons to the completely stock 250 in my 70 mustang. There are a couple of things I was wondering about.

First, does anyone have any idea as to what kind of power gain I could expect from porting and polishing the stock 250 head.

Second, could someone give me some suggestions as to which cam would be my best bet to choose.

 

[Anonymous]

What are your expectations with this motor. That will help determine what u want to look for.

 

[70stangcoupe]

I'd, of course, like to get as much power out of the motor as possible, but I'd like it to still be very streetable and able to drive in stop-and-go traffic. Im not all that concerned with gas mileage as long as its not extremely low.

 

[Anonymous]

I have gotten alot of info from this site

http://www.geocities.com/mustang_man_1966/

http://www.inlinepages.com/~inlinefever ... tions.html

http://inlinefever.homestead.com/RamAir.html

http://www.geocities.com/mustang_man_19 ... _tips.html

Mike at FSPP has a good selection of cams and there are quite a few guys here who are more knowledgeable about proper cam selection than I. I am running a 274 from FSPP.

 

[robbinsj]

I put the FSPP 264/274 with the 112* lobe center for the 250 in my '69 daily driver. Holy crap what a difference. The car is very driveable (especially with the new cable clutch on the T-5). I haven't had it in long enough to get a good read on the mileage, I'm still in the breakin period. I've got a Weber 38 and Clifford dual headers on as well. Make sure you get the timing set from 1970 and earlier. The cam timing was retarded by as much as 7* on the later 250 timing sets.
-Joey

 

[JackFish]

I put the FSPP 264/274 with the 112* lobe center for the 250 in my '69 daily driver. Holy crap what a difference. The car is very driveable (especially with the new cable clutch on the T-5)-Joey

I've been hoping for some reports on this cam, as I have one on the shelf to install.
Have you had head work done too? How is the carb mounted?
FSP also has this one that looks interesting:
http://cquesttechnologies.com/fspp/prod ... 2D10%2DDHS
It's 268/274@110*
Will a 110 LC work OK with an automatic?

 

[rbohm]

8) 110 lc will work just fine. 112 would be better, but not by enough to return the cam and get another. the only difference is that you would have a peak torque at a lower rpm, about 250-300 roughly with the 112 lc cam.

 

[CobraSix]

I'll yield on the cam question to those more knowledgable. I went with the Comp Cams 260H which has 110* seperation and it runs really nice with the 200.

As far as port and polishing the head I kind of yield to the addage of "polishing a turd" mentality. I did some mild polishing on my head. I think at stock internals and even with a hotter cam then stock, you'll notice little if any difference in real performance outside the mental boost. I'm sure it helps, but we are talking percentages here. I've seen some numbers where it adds 1-2%HP. Well on an engine with 100HP (for example) that would mean 102HP. Would u really notice that? on a 500HP engine it's an additional 10HP.

That being said, if you already have the head off and are bored some weekend, you might as well do it. However, I wouldn't pull the head specifically for just that purpose.

Slade

 

[robbinsj]

I looked real hard at the 110* but my primary purpose for the car is as a daily driver, so I went with the smoother idle and lower power band. I milled the head way too much and I also installed the 1.65 roller rockers. I'm putting the earlier timing set in now. Still working on the carb jetting with the Weber and getting the idle right. The 500 miles I've put on it so far have been a lot of fun, the engine pulls hard past 90mph....
-Joey

 

[addo]

I'll leave number theory to a certain seventh-state Aussie but will disagree with you there on the cam having an effect.

Having driven a 170-powered manual Falcon with a reground cam and near-stock carby/ignition, it did make a difference. Airflow in the head only comes into issue as you approach the limits of what it may provide, relative to what the motor now wants. As the air must go through the carby, there is no risk of it leaning out.

So -around town, it could be peppy and fun. Stretch it out and be disappointed when it strikes that wall.

Cheers, Adam.

 

[CobraSix]

I definitely recommend a cam upgrade. I too ran my 260 cam on a stock engine with electronic ignition as the only upgrade to the engine. Man what a difference. That's when my engines limiting factor seemed to shift from getting air/fuel into the cylinders and became the 1v carb's ability to get more air into the engine. Before I felt I wasn't pushing the carb and after I felt like the carb was beings pushed to the limit. Granted that is all conjecture on my part...

Slade

 

[70stangcoupe]

Thanks for all the advice guys. you will probably be hearing from me alot in the near future. Theres alot that I'm not sure about.

 

[Anonymous]

A wealth of info is available on the FSPP site. and if you run your cursor around topics go over 'TECH & LINKS' then when it comes out click on 'TECH INFO' then find 'selecting the right cam'----heck just click here http://www.cquesttechnologies.com/fspp/Selectingcam.asp
the info here says the 110 has a choppier idle but more low end power than the 112