What Manley valve is this?
 

BBC 3/8" stem ,2.19" dia., intake. Says "MANLEY B-LB". Is it a Severe Duty, 1 piece, SS? I need to replace 2 of them and dont know what to order. One of them says Manley M-LB.??

IF 2 HAVE FAILED,REPLACE THEM ALL.NO SENSE IN REPLACING ONLY 2 SINCE YOULL HAVE TO DO IT AGAIN LATER.PLUS,SINCE YOU HAVE THE HEADS OFF,YOU CAN PUT IN MANLEY STAINLESS SEVERE DUTY THEN YOULL KNOW WHAT YOU HAVE AND NOT HAVE TO WORRY.THE COMPLETE SET IS ABOUT 300 TO 400 WHICH IS MONEY WELL SPENT IN ORDER TO NOT MISS ANY MORE BOATING DAYS DOING THE SAME JOB AGAIN..BEEN THERE,DONE THAT!!!

The 2 that failed were not Manley, all the other are including the inconel exhausts. I think somebody changed these 2 once and put garbage valves in. Im pretty sure the manleys are severe duty, but I need to verify that based on whats printed on the valve. Thanks

Formula31, I just bought all new severe duty exhaust valves. They say J-YS on the stem and are the 1.88". Not sure that helps you much.

BT :cool:

I think that most knowledgable marine engine builders will tell you that in any hi-perf application you should be running Manley inconel (extreme duty) ex. valves and the stainless (severe duty) intakes. I had two expensive failiers with Manley severe duty ex. valves before I realized that you just can't use even very good street rod stuff in a marine engine. --- Jer

My exhausts are inconel but I have had the regular severe dutys survive for years at 450 hp. Its the intakes that are in question. Anybody have a number or site address for Manley?

The general consensus a while back from engine builders and gurus on OSO was that inconnel is a must in blown and very high hp marine engines. I take that as maybe 600hp+. I am only mildly modifying two 330 hps and will be lucky to see 450hp. Most said severe duty will work fine, although inconnel would be best. I think if nothing else fails and the engines are tuned properly, severe duty is good.

JP, what happened when your valves failed? Tuliping, or did the head come off?

BT :cool:

JimV says that an inconel valves have a tendency to beat the seats up more. That's one of his reasons, but he may have more. I just can't remember them all. I know in most cases he shuns away from them if he can.

I do NOT use inconel exhaust valves in my 540's. They are Ferrea high quality stainless steel one piece valves. I'm running with a totally DRY exhaust system. I have 50 hours with these valves and thus far no problems. :)

I am also running the Ferrea valves that KAAMA mentioned in a set of Dart heads that JimV did for me. They are on a blown 502 also with no problems and awet exhaust. If I remember correctly he also said they flow better.

If your engine builder can't tell you which valves you need, you need a new engine builder!!!
The address for Manley is www.manleyperformance.com.
I always recommend at least severe duty stainless valves in any marine application with Inconnel exhaust recommended and imperative in a high horsepower situation. The shape of the valve seems to be the same whether SD or Inconnel so I would expect the flow numbers to be the same, though I never did a back to back comparison.
I have used Ferrea and Manley valves with no known related problems with either one. Ferrea now has an exhaust valve that is supposed to be the best exhaust valve available-even better than Inconnel! They are used in Top Fuel and other such severe duty applications and they are said to be easy on seats and light in weight.
Also, the Manley Inconnel can be identified with a magnet. Just touch the valve with a magnet-it will be non-magnetic on the head and half way up the stem then MAGNETIC from there up.
I have seen immitators but this is the test for authenticity!!!
Hope this helps-Pm if I can answer any other questions for you


:D :D