Questions on my 74' 40 intake/exhaust gasket (1 Viewer)

[nitroid13]

I pulled my intake and exhaust headers and this is what I found. I'm going to take them to a machine shop and have them machined together so they are of equal thickness. Although they are very close and don't seem to require the half washers that other have used. I know the exhaust ports are leaking bad because of the soot around every port. I am worried that that back intake port wasn't sealing very well. My goal is to seal this up good enough to put a sniper efi set up on it. Any advice?

 

[charliemeyer007]

On my 72 I made longer studs. I also made my own stepped washers (1/4") and used stainless steel nuts with high heat anti seize compound . I run 2 man-a-fre header gaskets that were installed wet. I used a piece a glass and sand paper to "flatten the manifolds. I also cut a notch in the air cleaner bracket so I could easily get to the nut behind it. This set up has been on at least 2 engines and works great for me. I did the fluid heat riser thing too.

 

[nitroid13]

On my 72 I made longer studs. I also made my own stepped washers (1/4") and used stainless steel nuts with high heat anti seize compound . I run 2 man-a-fre header gaskets that were installed wet. I used a piece a glass and sand paper to "flatten the manifolds. I also cut a notch in the air cleaner bracket so I could easily get to the nut behind it. This set up has been on at least 2 engines and works great for me. I did the fluid heat riser thing too.

I live in the south so cold temperatures are not really an issue, so no real need for the heat riser to my knowledge unless I go up north. Now do you have any pictures of your washers? And why two header gaskets? And why wet? I haven't really seen that done. I think I seen were rimflex gaskets are better than oem for headers but I have only used oem

 

[charliemeyer007]

My dad was an aviation mechanic along with being a gifted welder and watchmaker. When I first got a header because the cast iron one cracked, I used one MAF gasket and half washers - it didn't last very long. Dad showed me how to plane the surfaces using a big piece of glass with sand paper stuck to it. The aluminum intake did need much, but the header did (raised weld bead). Gasket soak in warm water for 1/2 an hour is "softer" and allows the high spots to sink, making a better seal/contact on the low spots. Dad said use 2, so I did. I made the step washers from the head of 50 BMG brass. I can't the extras I made back in the 80's and I'm not taking one off. Because of all the extra thickness I need ed longer studs - dad scored some hi grade "redi-rod in the correct pitch and size to make the longer "studs" These same studs, gaskets and washers have been on at least 2 engines since 90's and have never leaked.

I can make and post a sample model out of 7.62 NATO if you want. I just used a hacksaw to cut off the head right where the inside web ends. De-primed the case with a punch. Drilled out the primer pocked to the next size larger than the studs, allows a little pivot action. Used a large flat file the flatten the washer, its concave when you cut it off. Then filed only half of the washer producing the step of about 1/4". I actually measured the intake and header flange and made the step to fit. There is about 1/8" of brass over the steel header and about 3/8" over the aluminum intake.

Actual 50 BMG bottle opener on right - hacksaw at black line. The rim sits on header, the step would sit on the intake. The 7.62 NATO model on left has to long of a step (too hard to hold shorten down to scale, being so small.

 

[dmaddox]

My advice would be to get an OEM exhaust manifold and ditch the header. Those headers are notorious for leaking. I wouldn't spend my cash on machining it. Get an OEM exhaust manifold, together get it planed with the intake...then pick up the SOR.com thicker manifold gasket, use new hardware, tighten and torque in the proper sequence and you're off to the races no matter what fuel delivery you choose!

Good luck!

 

[nitroid13]

My dad was an aviation mechanic along with being a gifted welder and watchmaker. When I first got a header because the cast iron one cracked, I used one MAF gasket and half washers - it didn't last very long. Dad showed me how to plane the surfaces using a big piece of glass with sand paper stuck to it. The aluminum intake did need much, but the header did (raised weld bead). Gasket soak in warm water for 1/2 an hour is "softer" and allows the high spots to sink, making a better seal/contact on the low spots. Dad said use 2, so I did. I made the step washers from the head of 50 BMG brass. I can't the extras I made back in the 80's and I'm not taking one off. Because of all the extra thickness I need ed longer studs - dad scored some hi grade "redi-rod in the correct pitch and size to make the longer "studs" These same studs, gaskets and washers have been on at least 2 engines since 90's and have never leaked.

I can make and post a sample model out of 7.62 NATO if you want. I just used a hacksaw to cut off the head right where the inside web ends. De-primed the case with a punch. Drilled out the primer pocked to the next size larger than the studs, allows a little pivot action. Used a large flat file the flatten the washer, its concave when you cut it off. Then filed only half of the washer producing the step of about 1/4". I actually measured the intake and header flange and made the step to fit. There is about 1/8" of brass over the steel header and about 3/8" over the aluminum intake.

Actual 50 BMG bottle opener on right - hacksaw at black line. The rim sits on header, the step would sit on the intake. The 7.62 NATO model on left has to long of a step (too hard to hold shorten down to scale, being so small.

View attachment 3402350

Thank you for that explanation, if I choose to keep the header then I'll probably do something similar

 

[nitroid13]

My advice would be to get an OEM exhaust manifold and ditch the header. Those headers are notorious for leaking. I wouldn't spend my cash on machining it. Get an OEM exhaust manifold, together get it planed with the intake...then pick up the SOR.com thicker manifold gasket, use new hardware, tighten and torque in the proper sequence and you're off to the races no matter what fuel delivery you choose!

Good luck!

Alright these are my options, I have 2 different headers a 6 to 1 and a 3.2.1 header as well. Now to the oem stuff I have. I have a 72 f intake/exhaust and I have a 83 fj60 2f intake/exhaust manifold. I know the 1f manifold has the ears on bothends cut/broken off and is severely out of alignment on the ports. Now the 2f is mostly complete and I will need some egr block off plates and gasket set for it. But the intake is cracked inside unfortunately. Not sure if it's worth it to weld it or to get a replacement. And of course both will need taking apart and new gaskets all around. I will also have to have an exhaust made for it as well unfortunately. Will also need the flange for the 2f. The exhaust riser flap is frozen on the 1f intake and the 2f works fine. Although I may delete them depending on which route I choose

 

[ETX FJ40]

Any links or advice to doing the Wet or double gasket method?

I also have the same issue with a leaking exhaust port.

 

[nitroid13]

Crazy patch job, I found that a mechanic did to the truck I got this manifold off of lol

 

[OlYellr]

I had my OEM manifold decked/planed at a machine shop - I used the OEM manifold gasket - later found a leak squirting starter fluid around the manifold gasket tying to solve my vacuum/carburetor issues - when I took everything off, the gasket was split down the middle (picture here) - I read posts and decide to try remflex - they are thicker and softer - you don't torque to the same specs as oem - was happy with the remflex - solved that leak, but in the end had more issues with the engine and had to take everything apart. Going back to remflex when I stab my engine next week. My experience - others milage may vary

I also got new OEM studs/bolts - seen where some people install a few more studs vs the 2 standard on the 2f engine - Look like I neat idea - but I had already ordered the studs

There are debates on the best gasket to use - might as well ask what is the best color. pick one and commit

 

[charliemeyer007]

Best manifold gasket? - https://forum.ih8mud.com/threads/best-manifold-gasket.1316935/#post-15042389