M151 new exaust gasket kits--do they work?

[gem1410]

I bought the intake and exaust gasket kit that came with the metal exaust gaskets--Have any of you tried the new kit?--Does it work--my m151a1 has had a bad exaust leak for many years--thanks

 

[cstaup]

I've never used the metal gasket kit. I've had pretty good luck with hi-temp copper gasket (rtv). If you exhaust manifold is warped bad enough not to maintain any seal (that;s what it sounds like), replace it.

 

[nattieleather]

If you need a new manifold I have one. The trick is to make sure both matting services are clean before installing the gaskets and to use a little goop (RTV etc made for exhaust) on the new gasket and it will seal up no problems.

If you have a leak you may have trouble getting the bolts out. Be very careful and take your time so that you don't break the bolts. PB Blaster and like products are your friend. Otherwise you may have to drill it out and use a longer bolt and nut.

 

[gem1410]

Thanks--I have a new exaust manifold--when I place it against the engine it rocks--a stright edge shows the metal between the center exaust holes is down some --are the manifolds very stright or warped some from the manufacturing--thanks

 

[cstaup]

A new manifold should be straight. Is yours warped? or is there a build up of material on the exhaust ports on the head?

 

[nattieleather]

There should be a natural rotation in the manifold because it is sitting in a saddle, but it should sit flush againts the ports on the head. If you have gaps between the head and the manifold you either have a bad manifold or crud on the head that needs to be cleaned or a bad head. Try taking a wire wheel and a drill and really clean the saddles out. Try to get some shinny metal on there and then see how things fit.

 

[gem1410]

I cleaned the saddle and the manifold did snug up--thanks for your help

 

[Tankjeepman]

They work good!

 

[cstaup]

I cleaned the saddle and the manifold did snug up--thanks for your help[/QUOTE

If you use the metal gaskets make sure that the intake manifold seats properly. I've read that those gaskets could "push" the exhaust out far enough to keep the intake just a hair from seating. This could cause a lean situation and result in engine damage. In my rebuild, I used Permatex Hi-Temp copper gasket (per above) on both the exhaust and a little on the intake , for insurance. No leaks at all (so far).

 

[gem1410]

I used the hi-temp on both manafolds and no leaks---the engine has a slight random miss--it has had this for 30 years--Is that nornal--I pluged the intake manifold openings thinking it was a vacume leak, changed the distrubutor,wires ,plugs and it still has the random miss--compression is 100+ lbs in each cylinder--any ideas---thanks

 

[majorhitt]

I'm in the middle of reworking my M151A1, It to had a random miss. Nothing too much to worry about. It too had a small exhaust leak. When I get to the motor I was going to add the gasket, It is metal against metal fit. A gasket would sound like a good thing.

 

[rickf]

151 and most A1's were designed to have a metal to metal fit on the exhaust manifold. If you use a gaskit kit on these you will usually end up with a intake manifold leak. The late style heavy duty head has more clearance around the exhaust manifold and is designed to use the gasket. The way to check for a manifold leak is to bring the engine up off of idle a little bit and then spray carb cleaner around the intake ports. Be sure to spray under the ports also since that is most likely where you will find a leak. When tightening the manifold bolts pay close attention to the tightening specs since the end bolts are different from the center bolts.

Rick

 

[gem1410]

thanks rick