offthefront

Starboard motor began not wanting to idle ...found wet plugs and 2 cylinders no compression ...Pulled the heads and found 2 valves open and slight impressions in Pistons ...head shop is inspecting the heads today ...we couldnt find any source for the water ..the Exhaust and risers had showed no signs of leaking esp inside ...no trail of water towards head ...any thoughts ?


These are stock 454 mags ...

Payton

What kind of exhaust? How are your flappers on or in the tips?

offthefront

Stock merc manifolds and risers ...Formula Silent Thunder ...I was thinking maybe need to check inside Flappers ? Outside are fine ...

offthefront

these are jasper Motors installed June 03 ..25 hours MAX ...run 46-5000 WOT. I have been doing some Prop tuning but really only at WOT a cpl of times and only one extended run ...10 mins max ....I dont hammer these motors ....usually 3000-3600 ...

cuda

Which valves were open? If an exhaust valve hangs open, it will suck water into the cylinder which sounds like what you have.

HeavyChevSS

Same ? as above about which pistons. Also didn't they make a heck of a noise. I had a guide hang up (Salt and sitting...) and it was pretty loud, thought I really broke something.

offthefront

Joe ... 4 and 5 ....the exhaust valves were hung open ..not sure if they were bent or what ....

Sutphen ...Stock bravo's ...not really any change in speed ..This motor has NOT got hot ...After a simular episode with port motor this spring I watch temps very close ....

cuda

I had the same thing happen on the SBC I built for the Minx. For some reason, the brand new crane hydraulic lifters wouldn't collapse down when I originally set them. I had to set them like solids.

offthefront

these mag motors have roller lifters but standard rockers ...I am thinking about going to roller rockers ....you know we never found the source for water in the port motor last spring ...it did get hot though ...but we tore it all apart ..did the heads ..new gaskets and since then has been fine ....

offthefront

hoping to hear something from Dover Head today ....Talked to Jasper Motor and warranty ran out in June ..they claim 18 month on their website but these "hi performance" motors only have 1 year ...what bothers me is 2 different Valves and seaperate heads ...