Intake manifold torque spec's/sequence?

[FJmoneypit]

I am still attempting to get rid of vacuum leaks around the manifold to head junction. Replaced gasket with no luck so I am going to double the gaskets up. My question is the torque spec and sequence for the manifold to head bolts/nuts and the intake manifold to exhaust manifold bolts.
I believe the manifold to head spec is 33 ft lbs? Thats what my Haynes stated.

She is a 1/76 FJ40 with stock 2f, carb/intake and exhaust manifolds.

Thanks

 

[Trollhole]

How about this. Straight from the FSM. Pretty sure you could figure out 7 & 8.

 

[Pighead]

I believe the manifold to head spec is 33 ft lbs? Thats what my Haynes stated.

That'd work for the OEM style gasket, feel free to re-torque a few times and a little tighter after running it. Also maybe look into a remflex gasket if doubling up doesn't fix it.

 

[Sam Stewart]

Is the leak actually coming from the gasket? Have you checked the head and manifold with a straight edge? Sounds like you might have a warpage problem.

 

[FJmoneypit]

Thanks for the info, just what I needed. I really, really need to get the FSM. the haynes is just not detailed enough. I will pick up my gasket set tomorrow so hopefully by the end of the week I will have the results. It does not appear that warpage is the major issue, so hopefully doubling up gaskets will work.

Thanks again

 

[Trollhole]

Thanks for the info, just what I needed. I really, really need to get the FSM. the haynes is just not detailed enough. I will pick up my gasket set tomorrow so hopefully by the end of the week I will have the results. It does not appear that warpage is the major issue, so hopefully doubling up gaskets will work.

Thanks again

In blue. https://forum.ih8mud.com/trollholes-cruisers/307029-great-cruiser-parts-link-thread.html


Merry Christmas

 

[77mustard40]

I'm fighting the same battle, not sure if I'm warped but will check when I have my do over. Going to try the Remflex this time.

 

[Steamer]

If the gasket has a little play in the bolt holes you might try pushing it up as you push the manifolds in to hold it up there till you snug up the nuts/bolts. This method took care of my exhaust leaks. Check post #7 here https://forum.ih8mud.com/40-55-series-tech/495122-warped-exhaust-manifold-f-engine.html

 

[FJmoneypit]

Thanks, I will take a look at the current gasket before I put her back together.

 

[KTP]

I'm fighting the same battle, not sure if I'm warped but will check when I have my do over. Going to try the Remflex this time.

Did that Remflex Gasket work? Because you are describing exactly what i'm going through. Nothing get more frustrating than working 6hrs and two gasket replacements and it still leaks. Agh!!!!

 

[brooklyn]

I had good luck with the Remflex after trying the stock gaskets. Remflex provides their suggested torque specs, but I used the torque specs above. Took a few times even with the Remflex to get everything torque until there were no more exhaust leaks. On some of the hard to reach bolts I ended up tightening until it felt like the other studs. All in all, took me three attempts. Also, found I had a leak at the base of the carb, which I overlooked because I was focusing on manifold gasket.

 

[coonassjohn]

Using 2 gaskets isn't a fix, just a band aid. The manifold is probably warped and needs to be trued.

 

[Ryan842]

I used a felpro gasket, my first attempt at tightening i snug them all up but not too tight. Once I ran the motor I noticed a leak, turned the motor off clean the carbon and nip all the bolts up again. I did this twice and now have no leaks.

 

[KTP]

I had good luck with the Remflex after trying the stock gaskets. Remflex provides their suggested torque specs, but I used the torque specs above. Took a few times even with the Remflex to get everything torque until there were no more exhaust leaks. On some of the hard to reach bolts I ended up tightening until it felt like the other studs. All in all, took me three attempts. Also, found I had a leak at the base of the carb, which I overlooked because I was focusing on manifold gasket.

Thank you for your words of wisdom. i'm waiting for my third Remflex to be delivered. I too will be Looking at other areas. So embarrassing the way it sounds right now. seriously sick of wasting my forth weekend trying to fix this issue. and since i still have ALL my smog lines it adds alot more time. again thank you for your time to help me.

 

[KTP]

I used a felpro gasket, my first attempt at tightening i snug them all up but not too tight. Once I ran the motor I noticed a leak, turned the motor off clean the carbon and nip all the bolts up again. I did this twice and now have no leaks.

i used the Felpro gasket this time with RTV just in case it may be warped and it still leaked. thank you for reply from down under

 

[KTP]

Thank you for your words of wisdom. i'm waiting for my third Remflex to be delivered. I too will be Looking at other areas. So embarrassing the way it sounds right now. seriously sick of wasting my forth weekend trying to fix this issue. and since i still have ALL my smog lines it adds alot more time. again thank you for your time to help me.

Using 2 gaskets isn't a fix, just a band aid. The manifold is probably warped and needs to be trued.

i agree, just not looking forward to ripping it all down with all my Carb compliant smog CRAP, 81' vacuum lines, AGH!!!!

 

[Nifski]

We have now gone through Two intakes that were cracked, they were welded and repaired and still leaked, we are now on our 3rd intake, they are difficult to find with no cracks due to the exhaust manifold heating the aluminum and cracking them from below, check your manifold correctly!

 

[AnthroHowl]

How about this. Straight from the FSM. Pretty sure you could figure out 7 & 8.
View attachment 582131

Which FSM is this from?

 

[Downey]

Ok, I'll beat the dead horse again. Back in the day we instructed guys who were installing exhaust Headers to use "Coppercoat" on all four surfaces (head, header, both sides of the gasket). Instructed to use the "paint-on can, not the spray-on can. Paint-on is a lacquer base, actually has small flakes of copper in it, bakes-on with the engine heat. Then we instructed to tighten until you think your wrench is going to break (which should strip a nut before it snaps a stud). This was the total remedy back in the day, and you know this also automatically applies to a leaking intake manifold as well.

 

[Rusto]

I had a leaky manifold on my 87 FJ60. It was due to warpage. I was able to sand the manifold down myself, used a remflex gasket and replaced the egr downpipe, carb to manifold gaskets and gaskets between the intake and exhaust manifold. It was time consuming as I have all the smog stuff intact, but it doesn't leak.

Also, with Remflex gaskets, I've been told that it is VERY important not to overtorque past their suggested specs. It crushes the gasket too much and the gasket fails.


Here is the thread. Not Needed (hopefully): Over-priced Machine Shop with experience resurfacing 2F intake/exhaust manifolds It meanders a bit, but it's all in there. My manifold was warped to the tune of .026" gaps in places. W/O sending it to a machinist, I was able to get it within .010" (within spec) in the worst spot and damn near .000 in others.

Doesn't leak one bit now. I only had to do it once, too. I would bet a considerable amount of money that your manifolds are warped. You should get a machinist straight edge and check it before you put it all back together again.