1969 250 Performance Mods?

[1961falconrat]

Hey guys! Well I finally picked up the engine I've been after, a 69' 250! Got it for $100 bucks! First thing I did when I got home was pull the head to see what I had found. I scored! the cylinder walls are great with no scoring or scratches and no ridges, the pistons look to be in good condition as well. The head needs work, #6 Exhaust valve has a chip out of it, but the seat of the valve looks fine. Anyway, I wanna build this engine to be a pretty healthy little beast, and from what I've read its not that hard to pull power out of it. I'm looking at a Comp Cam and lifter kit on summit, which is 260/260 Duration, .440/.440 Lift. and I'd like to go with bigger valves, im thinking the SI Port-Flow 1.75 from classic inlines. I have a local machinist that will do all the porting and honing. I'd like to go with a header, Siamese Port Divider from clifford, and an Electronic Distributor. I'm trying to stay away from boring and stroking for the time being because I don't have too much money haha. I have a 170 with adjustable rockers in it that are like brand new, should I put those in the 250? or stay with the stock ball-ball non-adjustable rockers? I'm not too sure what else to do, or if my ideas would work well, so i figured i'd ask you guys! I want to be able to drive it to school almost every day and go to the strip and turn a decent time. Im still in Highschool so I've got plenty of time for bigger modifications later down the road haha. So any Advice you seasoned Rodders can offer to a young rodder on what to put into this would be greatly appreciated!! Oh and also, its going into a 61' falcon wagon, I already have a c4 in it so all i need to do is build up this Engine and get goin! thanks again!

Vincent.

 

[rbohm]

8) ok, check out the cam selection at classicinlines.com before you buy from summit. the comp cams 260 grind is a good one, but not really designed for our sixes. CI sells clay smith cams, that are designed for our engines. i suggest a dual pattern cam with 110-112 degree lobe centers.

as to your rocker arm question, i would use the 170 rocker assembly on the 250 since they are adjustable.

as to valves, i would go with a 1.75in/1.50ex combination. have the shop that does the valve install unshroud the valves as much as possible for best flow.

unless you are going to build an Nth degree power plant, i would not bother with the port divider, they tend to be more trouble than they are worth.

as for electronic ignition, i would go with a dsll distributor and duraspark ignition with an msd blaster lll coil. this is probably the simplest upgrade for a young hot rodder to do as it is mostly bolt in with the right harness, which is available from ford last i knew.

 

[rocklord]

If the adjustable rockers from the 170 is used in the 250 you'll have to purchase a new set of pushrods (cup on top) for the 250 since they are longer than the 170's.
These are the ones you need: http://www.classicinlines.com/proddetai ... D250%2DANP

 

[CZLN6]

Howdy Falconrat:

And welcome to The FORUM! Yes, it is that good. While you'll hear varied opinions about the port divider, I suggest that you use one. But, have it fitted and properly welded into place while the head is disassembled. Then port to match the others.

You didn't specify what carb you will be using? That is a critical decision to be determined while the head is off.

In general, you've got the basics. You've gotten good suggestions on valve size, cam selection and rocker arms.

What ever cam you select, make sure you match it to the Pre-72 timing set.

On selecting a goal compression ratio, carefully consider what you are likely to do to the block when it comes time to do it. Know that one of the liabilities of the stock 250 block is the huge deck height at, typically, at .150". that's way too much for good combustion efficiency. On rebuild it can be dealt with, but final compression ratio must be considered now, because if you were to mill the head to maintain a 9:1 static ratio now, it would likely be unusable once the block is reconfigured to deal with the deck height problem. Check it out and plan now for the finished product.

Have you explored the roadblocks of putting the 250 into a '61 Falcon? Know that the '61 rear end will be geared very low for this combo, and weak. Just a thought.

Keep the info and questions coming.

Adios, David

 

[1961falconrat]

Hey guys Thanks for the Replies!

As to what what carb I am using, Im gonna be running a weber 32/36. I have thought about doing 3 singles or two deuces also but im not sure yet.

The Port Divider, I will probably use one and port it to match the others like CZLN6 suggested.

Now I was looking at distributors and came across a HEI for the 6. Would that be a good way to go other than the DsII? seems easier to me, but you guys know what works and what doesn't!

What I had planned to do is build this engine and run it in sept. But i'll probably hold off and just take my time and build it up for next years Nostalgia Drags. So that being said, I'll save up the money to deck the block, and bore and stroke it, and build the head to be a good compression head or what ever is the best way to go.

I figure I might as well do it right while i have it sitting out on the shop floor rather than rush my planning and go back in later and bore it out or run into problems.

Now i do realize that the rear end is a crap rear end haha its the stock wagon posi. I have a stock 8 inch out of a mustang, or i can get a 8.8 explorer posi from the wrecking yard for $200.

Thanks again Guys! Let me know what you think I Should Do!

Vincent.

 

[rbohm]

Now I was looking at distributors and came across a HEI for the 6. Would that be a good way to go other than the DsII? seems easier to me, but you guys know what works and what doesn't!

the dui dist is a good system fir a high end build or if you want the simplest wiring possible. the drawback is that it is quite expensive. the dsll system on the other hand is inexpensive, but requires a bit of wiring to install. its easy enough though if you know how to follow a wiring diagram. personally i would go with the dsll, unless i was building a race only car.

Now i do realize that the rear end is a crap rear end haha its the stock wagon posi. I have a stock 8 inch out of a mustang, or i can get a 8.8 explorer posi from the wrecking yard for $200.

Thanks again Guys! Let me know what you think I Should Do!

Vincent.

in regards to the rear end, i would go with the mustang 8" rear, even if you have to narrow it to work. it gives you a drop out center section so you can easily change gears if you want to deal with varying track conditions, or to have one gear for the street and one for the track.

 

[1961falconrat]

Alright, now to me this would be awesome, What are your thoughts on a supercharger? I can get a supercharger off a 3.8 t-bird, for $100 from the local wrecking yard. I figure go big if im gonna build a hot six, but im not sure if this would be a good way to go or not. They also have a T3 turbo.

as to the rear end, ill go with the 8" mustang and do some gearing to it.

And i might go with the dui, im not sure yet

Thanks again!

Vincent

 

[chad]

Alright, now to me this would be awesome, What are your thoughts on a supercharger? I can get a supercharger off a 3.8 t-bird, for $100 from the local wrecking yard. I figure go big if im gonna build a hot six, but im not sure if this would be a good way to go or not. They also have a T3 turbo.
Thanks again!
Vincent

We have a forum on this site for that Q...
may need other mods (arp bolts, etc...)

 

[rbohm]

Alright, now to me this would be awesome, What are your thoughts on a supercharger? I can get a supercharger off a 3.8 t-bird, for $100 from the local wrecking yard. I figure go big if im gonna build a hot six, but im not sure if this would be a good way to go or not. They also have a T3 turbo.

as to the rear end, ill go with the 8" mustang and do some gearing to it.

And i might go with the dui, im not sure yet

Thanks again!

Vincent

a supercharger would be cool thats for sure. you will have to fab up your own mounting brackets and belt drive though as there is no kit available for the ford small six. a turbo is easier to do, and draws far less power than the supercharger does.

for the 8" rear end, currie enterprises has all the parts you need to build it.