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Discussion Starter · #1 ·
I'm having low compression and vaccum reading issues due to the valve train not seating well,

I've made a compression test and it indicates valves not sealing well, I just lapped them so the seats are not the problem.

I belive they are kept open by the lifters.

Is it possible to convert them to adjustable, like the chevy engines?

Can I use chevy rocker arms in them? I6 or V8 pieces?

What is the rocker arm ratio of the I6 Ford engine?

thanks a lot.
 

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I'm having low compression and vaccum reading issues due to the valve train not seating well,

I've made a compression test and it indicates valves not sealing well, I just lapped them so the seats are not the problem.

I belive they are kept open by the lifters.

Is it possible to convert them to adjustable, like the chevy engines?

Can I use chevy rocker arms in them? I6 or V8 pieces?

What is the rocker arm ratio of the I6 Ford engine?

thanks a lot.
I'm not to sure that lapping if that's all you did will be adaquate, especially if this is a heavy duty or an emissions head with hardended seats.

So that leads me to the question as to whether you used a seat cutter/ grinder before lapping? Lapping alone as a seat restoration process makes the seats too wide and the valve ends up not settling well on the seat. Also, did you restore/replace the guides. When these get loose the valve rather orbits the seat having a hard time setting itself down.

Bogie
 

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Discussion Starter · #4 ·
You did not state the year of your engine. Early 300 six engines use guided cast rockers that can be lashed. Similar to the 289-302 early rockers.
it's a 1987 engine, came out of a E350 Econoline, it's installed now in my son's Granada.

I don't know about the early 289-302 rockers, this is my first time I deal with Ford engines.

the rockers are cast not stamped like the chevy units.

you mean there's a way to adjust them valves? shims or something?

the truth is I would love having a chevy-like system, adjustable by turning them loose 'til they make noise then tigthen down 1/2 turn, you know what I mean right?
 

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From the middle of the world
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Discussion Starter · #5 ·
I'm not to sure that lapping if that's all you did will be adaquate, especially if this is a heavy duty or an emissions head with hardended seats.

So that leads me to the question as to whether you used a seat cutter/ grinder before lapping? Lapping alone as a seat restoration process makes the seats too wide and the valve ends up not settling well on the seat. Also, did you restore/replace the guides. When these get loose the valve rather orbits the seat having a hard time setting itself down.

Bogie
I just lapped them to clean up the grime, the engine sat down for several years, the seats and valves are ok, not worn, so are the guides, they didn't need a restoration, the engine has low millage, they are not too wide now, I lapped them not to correct any problem, just a clean up job.
 

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Discussion Starter · #7 ·
the nut just bottoms out and can't be adjusted any further, do I need longer push rods or do I have to machine down the head bosses or the rockers?
 
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