4.0 ohv cyl head

[samx227]

blew the head gaskets on the ranger, it was misfiring on cold starts and then eventually started misfiring full time and that's when I decided to pull it apart. any way I never over heated it (according to temp guage) so I believe the heads are fine I just wanted to know if anyone knows what the clearances should be on the heads? thanks in advance!

 

[truckerdawg]

I have had the heads to crack and warp without overheating-these thin walled castings were made to save weight for the epa and fuel economy and are not heat friendly. I would have the heads magnafluxed and checked for warping before putting them back on-it's a lot of work to find the problem still exists or comes back real soon in the case of light warping.

 

[simpler=better]

x2 have a shop check them for flatness/cracks

 

[RonD]

Clearances?

Check between each valve seat, that is where they crack.

Should be under $150 to have both heads cleaned surfaced and pressure tested, under $100 in some places

 

[samx227]

clearances as in when measuring with a straight edge to see if they are warped. they measured at .03 on the deepest part if this makes sense to you guys
local machine shop wants $300 to clean and magnaflux them...

to the naked eye they look to be fine but yes it would be tons of work to just put it back together and it still have the same problem.

 

[baddis]

use a flat edge long enough to go across the whole head from end to end.

 

[RonD]

.03 or .003 and inches not mm right??

.003" would be right at the limit, .002" is the most you would like to see

 

[samx227]

Yes RonD thanks for that info. Well I gotta pull the block now because I dropped two little bolts in to the bottom end through the cam galley (I think that's what you call it lol) if it's not one thing it's another lol. I will let you guys know how she runs when I get it all back together. Should be this week

 

[cp2295]

Wow that sucks a lot have you tried using a magnet to get it out? Or is it just completely impossible to do a magnet? While you're pulling block definitely replace the rms! New clutch too and slave cylinder if you have a stick.. I hope it all goes smoothly!

 

[truckerdawg]

Hope that "$300 clean" means valve job and planing for that price. If not prices are quite high in your area. Good luck and don't forget to go back with fel-pro gaskets. Check out the many posts on the lower intake install too.

 

[samx227]

Tried using a magnet and it's a no lol the block is out and I'll start tearing it down tomorrow. I decided to do a rebuild since it's all out, this will be my first engine build so I'm pretty excited.
Cp2295 rms? And she just went through a automatic to manual swap about 2500 miles ago so everything is fresh!

 

[JoshT]

rms = Rear Main Seal

Have fun, I'm starting the same thing in a week or two. Not my first build, but hopefully it'll be the last time going into this engine.