Yeah, the heads came off and ratteled around; Major shrapnel throughout; Not pretty! The first time I was told that it was a one in a million fluke; the defective part that "never happens" but when it did it again midway thru the next season, crusing at a relatively moderate 4 to 4200 rpm just like the first time, I just knew that my luck couldn't be that bad and embarked on a serious quest for knowledge. I would never dispute Jim V but it was my understanding that the extra wear that inconel causes to seats isn't really a factor till you get into extreme spring pressures and rpm's. Also, Ferria makes a "superalloy" ex. valve (which I think is inconel by another name) with a terriffic record for durability and a better shape for flow than the Manley. Later! --- Jer

Well, you last two guys answered while I was writing and said it better. Sorry for the Ferrea misspell and thanks for the magnet tip! --- Jer

Just a note. I spoke to a Manley rep at the PRI show in Indy a couple of weeks ago and he said the blower exhaust valve material of choice these days is not inconel, but their new extremealloy. I guess inconel is obsolete or something!!:D Sometimes I think HP parts are worse than computers. I am really in the dark ages since I am using wimpy stainless severe duty valves on both my intakes and exhausts. I have never had a valve failure so I guess its a good enough material for my type of boating!:rolleyes: Not much help, but I thought some would be interested.

Blown1500, I build my own thank you and bought these heads from a reputable builder (from this site). On inspection this year, I find 2 intake valves slighly tuliped and they are not Manleys like the others are. Manley is closed till the first and thats why I was looking for some info so I could get these 2 valves replaced and back together. Do you know the Manley codes on the valves?? B-LB??

Formula 31,
If you are good enough to build your own, I congratulate you and you have my respect:D
You should be able to get info from some of the supply houses, such as Summit or maybe Doug Herbert in NC.
I have a Manley catalogue and if you would like, call me at
704-574-4020 and I'll gladely help all I can:D

Here is a photo of a manley inconnel on the left and a super alloy Ferrea on the right. The Ferrea valve flows four to six percent more air at any given lift.