OHV 4.0L correct exhaust manifold stud replacement?

[RussAdams]

I've been looking trying to find correct replacement studs for my 1999 Ranger 4.0L OHV.

My studs are:

M8 1.25
1.9 inches/49mm

The side that screws into the head is 1/2 inch/13 mm.

The shallowest hole on the head is .65 inch/16.45mm.

None of the exhaust manifold bolts I find on Amazon list the lengths.

Can anyone tell me which studs will work?


Any suggestions?

 

[alwaysFlOoReD]

Have you tried a dealership? I've been surprised at how reasonable some parts are.

 

[RussAdams]

Have you tried a dealership? I've been surprised at how reasonable some parts are.

I have not. Good suggestion.

 

[Broosedamoose]

Parts Geek has them: Studs

 

[RussAdams]

Parts Geek has them: Studs

Thanks for this! Unfortunately they only have 1 set of 4. I need all of them.

 

[gaz]

@RussAdams
Hello,
I've only ever replaced them with Stage8 locking header bolts. Their kits aren't the cheapest alternative but they require to be torqued once and stay that way

 

[RussAdams]

Stage8 locking header bolts

Are these what you're talking about?

Stage8 header bolts

With shipping about $85.00. Not cheap for sure. You obviously feel they are worth it. Care to explain?

 

[gaz]

@RussAdams
Yes sir. Those are all I've ever used on Ford OHV 2.9l and 4.0l.

The reason that they are worth paying for is they get torqued once and never need to be tightened again. Exhaust manifold bolts are known to loosen and require retorquing, I had heard this my entire life. When I first needed to mess with exhaust manifold hardware I took my mechanical mentors suggestion and bought a set of Stage8 locking bolts.

As said, though on the expensive side, some of the best money I've ever spent. Off the top of my head, the torque on the OHV 4.0l exhaust manifold bolts is only 22 or 25 ft/lbs, they truly benefit from the locking feature.

Either way, it's always nice to have options

 

[RussAdams]

As said, though on the expensive side, some of the best money I've ever spent.

That's quite the referral!

I'll give them a try.

 

[RussAdams]

So yesterday I talked with the folks that manufactured these heads.



The valve guides and seats are cast.



It would cost more to have a machine shop grind the seats and bore the guides and then ski

m the one head than it would to buy a new pair of heads.



Engine Quest sells new fully loaded heads for $620 for the pair.



They are Chinese cast, but built out and tested in Las Vegas.



Attached is a price list from a local machine shop.



I don't put more than 2-3000 miles a year on the truck.



I think I'm just going to replace the springs, seals and valves. Will lap the valves.



Then put it all back together.

 

[RussAdams]

I've finished the heads.

Painted them with flat black Rustoleum hightemp head engine paint, and installed new seals, springs, valves. Applied a liberal amount of assembly lube when putting it back together.

Lapped the valves as best I could before installing them.

 

[RussAdams]

<snip>

Stage8 locking bolts.

<snip>

As said, though on the expensive side, some of the best money I've ever spent.

Following Gaz' recommendation I installed the exhaust manifolds to the heads using Stage8 locking bolts. If nothing else they look pretty:

Painted with POR15 high temp flat black from a rattle can. Baked in the oven at 450F for two hours.

 

[gaz]

@RussAdams
Looks like you've put some time into this, good job.

Machining prices vary from area to area...shoppe to shoppe, the performance valve job I had done on my 4.0l was $240 plus parts; the money that I would have spent on new castings or assembled refurbished heads, I spent on a bored out throttle body and custom reground cam.

The machinist I use, the valve seats and guides are part of the "valve job". I can't imagine a machinist performing a valve job without doing the guides??? I have done some machine shop work and the guides were always done as part of the valve job. Sorry to learn this about your local place; sounds like they 1st charge customers for toilet paper and 2nd to flush.

I hope that you report on how you work pans out . That POR15 is some truly interesting stuff!!