250 head buildup...need advice

[blueroo]

I'm giving some serious thought to starting a 250 head buildup over the summer but before I start it I'd like to have everything I need established.

Here's what I have so far in terms of what I'll need:

1) 250 head, D7 type
2) 3 Ford Tempo/Mercury Topaz 4 cylinder CFI throttle bodies
3) 3 small round chrome open element air cleaners
4) Meqasquirt EFI system
5) Electric fuel pump
6) Head gasket
7) Classic Inlines Header
8 ) Classic Inlines header gasket
9) Exhaust Port Divider

Now for some of the things I'm not sure of:

1) Can I use my 170 valve cover with the 250 head?
2) Will I need a new rocker arm assembly?
3) New lifters and pushrods?
4) T-stat housing?
5) Can I use Comp Cams beehive style valve springs?
6) I plan on going to a DUI system but until I do, what do I do with the vac advance on the stock dizzy?

 

[CoupeBoy]

1) Can I use my 170 valve cover with the 250 head?

Yes.

2) Will I need a new rocker arm assembly?

No

3) New lifters and pushrods?

You shouldn't have to change any of that

4) T-stat housing?

Use the old one

5) Can I use Comp Cams beehive style valve springs?

Not sure, I havent really looked into them.

6) I plan on going to a DUI system but until I do, what do I do with the vac advance on the stock dizzy?

I'm guessing this is a L-O-M dizzy? You have to use a stock carb that has an integral SCV until you are ready to upgrade your distributor. Or upgrade sooner.

-ron

 

[CZLN6]

Howdy:

FYI-
The 250 engines use a longer pushrod than smaller engines.

The 250 T-stat housing has a 1.75" outlet as compared to a 1.5" outlet on 144, 170 and 200s. They are interchangeable and a simple solution to the 250 into a 200 swap is to use the 200 housing on the 250 head. Otherwise you will have to use the larger diameter 250 radiator hose and use adapter rings to fit it to the 200 radiator bungs.

250 engines 1st appeared in '69 and never used a L-o-M distributor. So depending on what carb, cam and distributor you're using, it will either be a ported vacuum source or manifold vacuum source. All stock type OEM carbs, after '68, have a ported vacuum source. Even Holley and Autolite 2V. With a stock cam/ high vacuum engine use the ported source. If you are using a longer duration cam that lessens vacuum you may want to use a manifold vacuum source. As usual, trial and assessment will give you the best answer for your situation.

If you find an answer to using the beehive valve springs on these heads be sure to share the info.

Adios, David

 

[CoupeBoy]

The 250 engines use a longer pushrod than smaller engines.

I assumed he was putting the 250 head onto his 170 block and that he would need to retain the solid lifters/cupped pushrods/adjustable rockers that he is already using.

The 250 T-stat housing has a 1.75" outlet as compared to a 1.5" outlet on 144, 170 and 200s. They are interchangeable and a simple solution to the 250 into a 200 swap is to use the 200 housing on the 250 head.

I also assumed that he would be reusing his current t-stat housing. And that other then the physical casting of the head and valves everything else would most likely be re-used. I thought a 170 of his era would have the L-O-M.

-ron

 

[CZLN6]

Howdy Back:

You're right Ron. Sorry, I should have read and reread completely. I get it now and I'm with you.

Adios, David

 

[blueroo]

I don't plan on using a carb since I really want fuel injection. I'm planning on using three Tempo/Topaz CFI throttle bodies to give the look of triple carbs.

And yes, I know, I don't really need three TBs but what I'm looking at is by having each TB mainly feed two cylinders I can even out the amount of fuel each cylinder recieves resulting in better response.

The use of throttle bodies is why I asked about the stock dizzy. As there will be no carbs, what do I do with the vac advance?


Now, this might throw a wrinkle in here. My 170, from what I can tell is a partial mix of the early and late design. It has the weaker bottom end of the early design but it came with hydraulic lifters unlike the solids of some of the early blocks. However, I have since changed over to a solid setup.



As for finding out about the beehives, what are the specs of our stock springs? I saw this different stuff about installed height, etc.

 

[CoupeBoy]

When you go to using the TBIs hook up the distributor vacuum to the intake log directly.

And it really doesnt matter which valvetrain setup you have now, solid or hydraulic. Unbolt the rocker assembly from the head and bolt it onto the 'new head' re-use everything else.

-ron

 

[63redtudor]

blueroo, my '63 170 has a similar mix to yours. It has the adjustable rocker arms, hydraulic lifters & the 1/4" oil pump shaft. I was able to confirm the lifters when I did a head swap several years ago.
My '65 200 has the 5/16" shaft, but otherwise has the same valve train.
I have also found a '64 144 with the adjustable rocker arms, 5/16" shaft & while I haven't been able to pull the head, I think that it has hydraulic lifters.
As near as I can tell, all of these engines are original, I guess Ford kept the adjustable valve train for several years after they went to the hydraulic lifters.
Edwin

 

[wallaka]

I don't plan on using a carb since I really want fuel injection. I'm planning on using three Tempo/Topaz CFI throttle bodies to give the look of triple carbs.

And yes, I know, I don't really need three TBs but what I'm looking at is by having each TB mainly feed two cylinders I can even out the amount of fuel each cylinder recieves resulting in better response.

The use of throttle bodies is why I asked about the stock dizzy. As there will be no carbs, what do I do with the vac advance?


Now, this might throw a wrinkle in here. My 170, from what I can tell is a partial mix of the early and late design. It has the weaker bottom end of the early design but it came with hydraulic lifters unlike the solids of some of the early blocks. However, I have since changed over to a solid setup.



As for finding out about the beehives, what are the specs of our stock springs? I saw this different stuff about installed height, etc.

You should be able to use 73-78 302 exhaust springs, beehive or not. They are the same length and as 200 springs.

2" free length, 1.59" closed and 1.22" open. Around 80 lbs. closed/200 open would be a nice strength.