'77 fj40 carb/intake "fun" (1 Viewer)

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After reading on this great forum about all the related issues & solutions for idling problems/ vacuum leaks, I felt I need to investigate. Sooo, upon carb removal, I look down the in the plenum, and lo and behold, I find what the PO had done! Booger welds galore! And a crack still growing. See pics- So, I've researched and found the "best aluminum welder" guy here in Southeastern AZ, (according to several other welders) He said he charges $50/hr. Sold! Next I'm vacillating between OEM, Felpro & Remflex manifold-to-head gaskets. Plus I'm trying to choose which carb kit to buy- prices vary greatly. I can't seem to separate the Bakelite spacer from the carb bottom btw...I'm considering the removal of the exhaust's heat-riser flapper-valve with a block-off plate, and plugging the shaft holes as shown elsewhere on this forum. But I don't want to "fix" anything else that ain't broken, but want to do this whole thing just once, if possible. Please chime in with comments or suggestions! Thanks all!

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Update- with no comments yet, I hope this isn't too boring for all, but for me, it's been a real lesson in doing proper due-diligence- so after some effort and head-scratching, I finally got the manifolds off today. See Pics attached. That rear-most manifold bolt up against the firewall was lotsa fun! Now the surprise- All the lower manifold bolts were just finger tight! Yikes! Thank you, PO. Anyway, nothing broke or stripped during removal, thankfully. 3 questions- The gasket didn't appear to be leaking as far as I could see, and I'm curious, can anyone tell what mfr. this one is? Also, there is some oil laying on the bottom of the intake ports- is this leaky valve stem seals? Or what? Lastly, the exhaust heat-riser flap sure seems to provide a lot a restriction to flow even when wide open, so would removing it altogether free up flow? (I'm looking at Kurt's plate) Now it's off to the welders Monday after I separate the two manifolds.

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does the flapper move? when cold it directs exhaust up to the bottom of the intake, after it gets warm it is supposed to rotate and direct the exhaust down the exhaust pipe. in that position it does not position it does not restrict flow. When it doesn't rotate it overheats the intake and cracks it.

My guess on the oil in all the intakes is maybe you either have some blow by or the PCV is not working correctly.
 
does the flapper move? when cold it directs exhaust up to the bottom of the intake, after it gets warm it is supposed to rotate and direct the exhaust down the exhaust pipe. in that position it does not position it does not restrict flow. When it doesn't rotate it overheats the intake and cracks it.

My guess on the oil in all the intakes is maybe you either have some blow by or the PCV is not working correctly.
3_pups, yes, the flapper does rotate fairly freely by hand, and springs back closed. It seems to work as designed, but I do have the cracked intake to deal with unfortunately. I'm thinking to increase exhaust flow by removing it anyway, but haven't decided yet...
 
Before you have those boogers 'picked' :rolleyes: , I had the same and elected to find a 'new' used intake manifold... I got one from Georg ( @orangefj45 ), but I'm pretty sure Mark (@65swb45 ) moved a bunch to his post-warehouse fire "Lemonaid Stand".

Call Mark (he's doesn't do PM) and see what he says... Before you have your's patched...

A carbureted man in a fuel injected world. my website: marksoffroad.net
I use the Internet to promote my business; I use a telephone to conduct it.

TLCA #1086. 65SWB45, 64LWB45, 68FJ40, 69FJ40[the karma cruiser], 76K5, 97Sub5.7, 2015 Trax, and a few steel strings, to go with the steel horses.;) proud member of TWTOTEC.
THANK YOU FOR YOUR PATRONAGE...AND YOUR PATIENCE. 818-953-9230
I would use an OEM gasket and have whichever manifolds you end up with surfaced, to ensure they fit tight.
 
I have used the OEM gasket twice, once 13 years ago...zero issues. Did OEM on another last year. Have a machine shop mill or whatevet they call it.
 
Before you have those boogers 'picked' :rolleyes: , I had the same and elected to find a 'new' used intake manifold... I got one from Georg ( @orangefj45 ), but I'm pretty sure Mark (@65swb45 ) moved a bunch to his post-warehouse fire "Lemonaid Stand".

Call Mark (he's doesn't do PM) and see what he says... Before you have your's patched...

A carbureted man in a fuel injected world. my website: marksoffroad.net
I use the Internet to promote my business; I use a telephone to conduct it.

TLCA #1086. 65SWB45, 64LWB45, 68FJ40, 69FJ40[the karma cruiser], 76K5, 97Sub5.7, 2015 Trax, and a few steel strings, to go with the steel horses.;) proud member of TWTOTEC.
THANK YOU FOR YOUR PATRONAGE...AND YOUR PATIENCE. 818-953-9230
I would use an OEM gasket and have whichever manifolds you end up with surfaced, to ensure they fit tight.

Thanks for the props Danny. I meant to chime in here, but I've been busy playing catch-up from my trip.

I've said this before: IMO a cracked and welded manifold is probably better than an uncracked one that hasn't been matched to the exhaust.
 
Thanks guys for suggestions. I've dropped off the offender at the TIG welders. Got a remflex gasket kit on order, removed the heat riser flapper mechanism & plugged the holes, found and ordered an air rail check valve, and then ordered a carb rebuild kit from Kurt! I'm on a roll, relatively speaking LOL. UPDATE! the check valve is out-of stock! Damn!
 
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Thanks guys for suggestions. I've dropped off the offender at the TIG welders. Got a remflex gasket kit on order, removed the heat riser flapper mechanism & plugged the holes, found and ordered an air rail check valve, and then ordered a carb rebuild kit from Kurt! I'm on a roll, relatively speaking LOL.

Where'd you find the remflex gasket?
 
I would be concerned about where all that oil is coming from inside the intake. It wouldn't hurt to do a compression check of all the cylinders while it is apart.

I had a similar problem.
 
Where'd you find the remflex gasket?

More importantly, why do you think you need a Remflex gasket? One of my mottos is that I would not sell anything I wouldn't install. And I would not sell or install a Remflex gasket. Period.
 
There isn't anything inherently wrong with Remflex gaskets BUT some people expect miracles where the problem is severely messed-up or uneven sealing surfaces. It won't perform miracles. I have a Remflex gasket on another engine for at least 10 years and it has performed well. The reason I used it was b/c I "de-siamesed" my intake ports for performance reasons and the OEM gasket wouldn't work. Remflex made a custom gasket for that application.
 
I would be concerned about where all that oil is coming from inside the intake. It wouldn't hurt to do a compression check of all the cylinders while it is apart.

I had a similar problem.
Yes I will do that. Please share what you found your similar problem to be?
 
More importantly, why do you think you need a Remflex gasket? One of my mottos is that I would not sell anything I wouldn't install. And I would not sell or install a Remflex gasket. Period.
Mark- Someone (pin_head?) said in another related thread "to just use a Remflex and forget it", so I took that to mean they're quite good.
 
I stand by what I wrote. I replaced a Remfex gasket that failed on Kelly O's 40. I came off in six pieces! The only other gasket I have seen fail that miserably is SOR's much-touted kevlar gasket. Buy OE for the stock 2F manifold.
 
Even on a properly machined head and manifolds that are resurfaced I'll use a remflex. Awesome gaskets. And as long as you use them properly last a really long time. Not beating on the Toyota gaskets but I'd recommend a remflex to a novice over a toyota gasket all day long. 7 years in on a few I've installed.
 
Please share what you found your similar problem to be?

Broken piston rings on 5 of 6 pistons, skirts broken on 4 of the 6 pistons. Camshaft was worn down severely, I was totally unable to get a solid valve adjustment. I wound up having a build up of carbon so bad in the exhaust ports in the head that I don't know how the mighty 2F was still running. Browse through my build thread and amuse yourself!
 
Mark- Someone (pin_head?) said in another related thread "to just use a Remflex and forget it", so I took that to mean they're quite good.

I spoke with Onur (Beno) a few weeks ago and he also suggested I go with Remflex over OE given my application.
 

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