250 cam specs?

[pro94]

What is the cam specs for a stock 250 cam. The guy I bought the engine from said it came out of a truck, with a stick shift. it had a d7 head on it.

 

[Anlushac11]

8)

I could be wrong but I thought it was about 252 deg duration and .390" lift

 

[Hot 6t Falcon]

Howdy,

The specs for a '69 hydraulic cam are 256 degrees.
Intake opens 10 btdc; closes 66 abc
Exhaust opens 58 bbc, closes 18 atc
Overlap is 28 degrees
and lift is .368

Cam timing changed as Ford moved into EPA engines. but I've never bothered keeping those numbers.

Most important change on a 250 engine was the timing gear was more and more advanced after about '75 by about 7 degrees. Good for lower emisions, but bad for power.

So when you are going to put on a new timing chain ALWAYS specify one for a '69 250.

Finally - a 250 in a TRUCK??? I don't think so..... but I'd be willing to learn something new.

PS. the timing gear on a 200 did NOT change.

 

[JackFish]

Most important change on a 250 engine was the timing gear was more and more advanced after about '75 by about 7 degrees. Good for lower emisions, but bad for power.

Did you mean "retarded" the timing?

 

[pro94]

Finally - a 250 in a TRUCK??? I don't think so..... but I'd be willing to learn something new

Yea, I saw the truck it came out of. I bought the engine off ebay for 50 bucks running motor totally complete. I drove down to dothan, al to pick it up. and it was sitting in this guys shop next to some old ford truck. and he said he pulled the engine out of the truck, cause he had a crate 302 he was dropping in which was there in the shop also. I didnt go into detail about the truck. just short small talk. I was just happy to get the 250 loaded up. and be on my way. so thats all I really know about it.

 

[Hot 6t Falcon]

Jackfish wrote "Did you mean "retarded" the timing?"


The '69 chain and crank gear look the same as a ‘75, but when the '69 cam gear is put on top of the '75 cam gear, lining up the teeth, the keyway in the ‘69 gear seems to be about 1/16" more clockwise than the ‘75.

I think Clockwise rotation means advanced, but I do get confused in my old age.. That crudely calculates to be about 7 degrees (3 1/2 crank degrees).

Retarding the cam usually gives more low end grunt (highly technical term there), and Ford certainly didn't do that.

Ford did retard the ignition timing.

Pro94,

Take another look at this engine. Does the intake manifold unbolt from the block? or is the intake manifold log cast right onto the head.?

 

[MustangSix]

Retarding the cam usually gives more low end grunt (highly technical term there), and Ford certainly didn't do that.

Ford did retard the ignition timing.

It's the other way around. Retarding the cam decreases cylinder pressure at low speed and shifts the torque and power curves to a higher rpm. They did this to reduce the cylinder pressure for the sake of NOx emissions.

Advancing the cam has the opposite effect; it increases cylinder pressure at lower rpm and increases bottom end grunt by shifting the curve down.

 

[Lazy JW]

Jack is correct. I dunno about the small sixes because I have never worked on any, but I did verify that Ford indeed retarded the cam timing on my 1981 300 by 4º.
Joe

 

[pro94]

Take another look at this engine. Does the intake manifold unbolt from the block? or is the intake manifold log cast right onto the head.?

No, its cast on to the head. its a 250. I know how to identify the differences between the I6's. just I didnt know about a 250 in a truck. I will try to find the guys email and get in touch with him and see whats up.

 

[Anlushac11]

8)

Just out of curiositydoes the engine have a rear sump or front sump oil pan?

Which oil pan do you need?

 

[pro94]

Just out of curiositydoes the engine have a rear sump or front sump oil pan?

Which oil pan do you need?

I dont remember. I think its a front sump. Im not for shure which one Im gonna need. Chris Alston's is gonna build me a custom 2x3 tube chassis for it. so it will be rack and pinion and a arm front suspension, back half the whole 9 yards. so I dot know what pan I need yet.

Turbo 250 I6, 4 speed, pro street