sbt rave valves

[DaddyLoafin]

I've read that SBT rave valves don't need to be trimmed back at all unless your going over 1mm oversized. Is this true?

 

[DaddyLoafin]

It is not true. They are for standard bore.

 

[WAJimmy]

I just had my 787 rebuilt and I asked the mechanic about shaving back the rave valves as the cylinder was bored out 50 over and he said just add double gaskets and that will work. Ever heard of that? Well, I trusted him and took it out on the river and my rave valve cover melted and dropped my valve into the cylinder while running. Not sure why that happened.

 

[DaddyLoafin]

I just had my 787 rebuilt and I asked the mechanic about shaving back the rave valves as the cylinder was bored out 50 over and he said just add double gaskets and that will work. Ever heard of that? Well, I trusted him and took it out on the river and my rave valve cover melted and dropped my valve into the cylinder while running. Not sure why that happened.

That won’t do anything to prevent the raves from hitting the piston rings. You have to remove material to make clearance

 

[etemplet]

I melted a rave piston in a matter of minutes. I believe the gasket I installed with the valve body was contacting the rave valve and caused it to hang up. Still not sure how the heat came up the shaft but it hasn't happened again.

 

[WAJimmy]

That is what I was thinking, so thank you. I am mechanically inclined and that didn't make any sense to me, but my mechanic said SBT is the one that said to do that. Now, would that cause it to melt my rave valve cover? this is the second set up valves and now brand new housing, so it's starting to get a little expensive. Still not sure if I am going to have to rebuild it again, can't find my compression checker. How does this piston look? Took the metal shavings out.

 

[etemplet]

After thinking about what @DaddyLoafin said, I can't imagine SBT saying something like that. The height of the housing has no effect on the valve landing or distance to the piston. My GTX destroyed the threads on the rave pistons on 2 valves in succession and only on the mag cylinder. You don't get much help a all with problems like this, you generally have to solve them yourself. I called an engine builder that had no clue.

 

[WAJimmy]

After thinking about what @DaddyLoafin said, I can't imagine SBT saying something like that. The height of the housing has no effect on the valve landing or distance to the piston. My GTX destroyed the threads on the rave pistons on 2 valves in succession and only on the mag cylinder. You don't get much help a all with problems like this, you generally have to solve them yourself. I called an engine builder that had no clue.

Thank you. I appreciate the feedback and I should have listened to my gut and not a mechanic. He is saying now that the rave valve breaking up was not his fault and was not a mechanical issue, so it's not under his warranty.

 

[DaddyLoafin]

After thinking about what @DaddyLoafin said, I can't imagine SBT saying something like that. The height of the housing has no effect on the valve landing or distance to the piston. My GTX destroyed the threads on the rave pistons on 2 valves in succession and only on the mag cylinder. You don't get much help an all with problems like this, you generally have to solve them yourself. I called an engine builder that had no clue.

I had called them and the guy I talked to told me that they were made for stock bore and had to be shaved.

I remember reading online somewhere where someone said that they were made for whatever bore sbt uses but that is not true.

 

[etemplet]

I had called them and the guy I talked to told me that they were made for stock bore and had to be shaved.

I remember reading online somewhere where someone said that they were made for whatever bore sbt uses but that is not true.

I have never bought an engine from SBT but I thought if they sent you and engine the raves were sized to fit. I took a couple of SBT engines apart, one failed before 5 hours run time. I thought people were biased against SBT but after I saw the kind of work they do I'd never put one of their engines in anything. Sad but that's my experience and it is OK to disagree.

 

[DaddyLoafin]

I have never bought an engine from SBT but I thought if they sent you and engine the raves were sized to fit. I took a couple of SBT engines apart, one failed before 5 hours run time. I thought people were biased against SBT but after I saw the kind of work they do I'd never put one of their engines in anything. Sad but that's my experience and it is OK to disagree.

I've never had any experience with an sbt engine so I cant say but even the guy who use to own my local Seadoo dealer told me that its not uncommon for them to fail after he put them in, but that was 4tecs. I would assume they cut the valves to whatever size they need for the bore but again cant say for certain.

 

[etemplet]

I've never had any experience with an sbt engine so I cant say but even the guy who use to own my local Seadoo dealer told me that its not uncommon for them to fail after he put them in, but that was 4tecs. I would assume they cut the valves to whatever size they need for the bore but again cant say for certain.

I would think the valves are sized as well but just something you need to check. I use SES and have had to address issues on my last 3 engines. The only reason I use Tom is that when I can't get an engine apart he can and does save them.

 

[DaddyLoafin]

I would think the valves are sized as well but just something you need to check. I use SES and have had to address issues on my last 3 engines. The only reason I use Tom is that when I can't get an engine apart he can and does save them.

lol how are his return times lately? I live about 40 minutes from his shop. I had talked to the guy who use to own the local seadoo dealer about SES and he said they do good work but would say a single word else lol

 

[etemplet]

lol how are his return times lately? I live about 40 minutes from his shop. I had talked to the guy who use to own the local seadoo dealer about SES and he said they do good work but would say a single word else lol

He is a year overdue on 2 engines for me. I'm not stupid enough to send him an engine I need. I've been working with Tom for 5 years and I know his capabilities. He is a great resource for me and I get good information from him.