problem with aftermarket cylinder heads.
10-15-2015, 05:51 PM
#31
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10-15-2015, 05:52 PM
#32
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http://www.offshoreonly.com/forums/d...ml#post4231501
Or maybe they are not.
Scott Stinebring would then be required to disassemble the heads, as any proper engine builder would do, measure guide clearances, and any other dimensional measurements he would feel necessary as the lead engine builder, and then provide that information to Kevin.
Bob
10-15-2015, 05:59 PM
#33
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Sure you are speaking of seat run out ? I'm having a problem with a answer.... I use a Sunnen VGS 20.. I try to use, carbide pilots, which help in deflection... I always check them for straightness, cutter speed and pressure affect your seat run out, worn pilots and tool holders contribute to run out...I always, use marking dye on my seats, with a very fine lapping compound to check seats.
Seat run out, is important, during the machining process.... the problem arises when the valve to guide clearance widens and the valve starts walking all over the valve seat, the intake valve is larger so the more clearance , the more it will deflect and increase seat run out. So, now you just defeated the purpose of a good valve job... .002-.0025 on a 11/32 valve is excessive. That leads to a nice "coat Hanger " affect on valve stem especially on the intake, that will lead to a broken valve....If the guide is straight, and concentric, no reason to make it bigger, intake cooled and lubed with fuel, the exhaust is .0005' larger, in clearance for heat, take the oil away your done... When you run methanol as fuel, we add a top end lube, helps valves and prevents corrosion in fuel system , most guys still may run racing gas for warm up or flushing system after use...
My equipment is only used for my builds, I do not like or do send out the door machine work... one reason, is I have enough to do for myself. I bought my equipment so I had full control of my machine work without headaches..
Seat run out, is important, during the machining process.... the problem arises when the valve to guide clearance widens and the valve starts walking all over the valve seat, the intake valve is larger so the more clearance , the more it will deflect and increase seat run out. So, now you just defeated the purpose of a good valve job... .002-.0025 on a 11/32 valve is excessive. That leads to a nice "coat Hanger " affect on valve stem especially on the intake, that will lead to a broken valve....If the guide is straight, and concentric, no reason to make it bigger, intake cooled and lubed with fuel, the exhaust is .0005' larger, in clearance for heat, take the oil away your done... When you run methanol as fuel, we add a top end lube, helps valves and prevents corrosion in fuel system , most guys still may run racing gas for warm up or flushing system after use...
My equipment is only used for my builds, I do not like or do send out the door machine work... one reason, is I have enough to do for myself. I bought my equipment so I had full control of my machine work without headaches..
10-15-2015, 06:14 PM
#34
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Sure you are speaking of seat run out ? I'm having a problem with a answer.... I use a Sunnen VGS 20.. I try to use, carbide pilots, which help in deflection... I always check them for straightness, cutter speed and pressure affect your seat run out, worn pilots and tool holders contribute to run out...I always, use marking dye on my seats, with a very fine lapping compound to check seats.
Seat run out, is important, during the machining process.... the problem arises when the valve to guide clearance widens and the valve starts walking all over the valve seat, the intake valve is larger so the more clearance , the more it will deflect and increase seat run out. So, now you just defeated the purpose of a good valve job... .002-.0025 on a 11/32 valve is excessive. That leads to a nice "coat Hanger " affect on valve stem especially on the intake, that will lead to a broken valve....If the guide is straight, and concentric, no reason to make it bigger, intake cooled and lubed with fuel, the exhaust is .0005' larger, in clearance for heat, take the oil away your done... When you run methanol as fuel, we add a top end lube, helps valves and prevents corrosion in fuel system , most guys still may run racing gas for warm up or flushing system after use...
My equipment is only used for my builds, I do not like or do send out the door machine work... one reason, is I have enough to do for myself. I bought my equipment so I had full control of my machine work without headaches..
Seat run out, is important, during the machining process.... the problem arises when the valve to guide clearance widens and the valve starts walking all over the valve seat, the intake valve is larger so the more clearance , the more it will deflect and increase seat run out. So, now you just defeated the purpose of a good valve job... .002-.0025 on a 11/32 valve is excessive. That leads to a nice "coat Hanger " affect on valve stem especially on the intake, that will lead to a broken valve....If the guide is straight, and concentric, no reason to make it bigger, intake cooled and lubed with fuel, the exhaust is .0005' larger, in clearance for heat, take the oil away your done... When you run methanol as fuel, we add a top end lube, helps valves and prevents corrosion in fuel system , most guys still may run racing gas for warm up or flushing system after use...
My equipment is only used for my builds, I do not like or do send out the door machine work... one reason, is I have enough to do for myself. I bought my equipment so I had full control of my machine work without headaches..
10-15-2015, 06:15 PM
#35
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Back years ago, I ran into a issue with some Dart Heads, that had inferior valve guides... Dart stopped using CHE, for guides and got some SH;;t soft material... these were heads with Jesel shaft rockers, the guides went to so wide of a clearance it was like for a 3/8 valve, bronze material in oil, had a cylinder head that worked for one of the teams in Charlotte, have the guide tested for hardness, needless to say it did meet spec material... All new guides, back together, never a issue again... Be rest assured, that guide was removed from Darts production, this was like 2005-2006
10-15-2015, 06:21 PM
#36
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Back years ago, I ran into a issue with some Dart Heads, that had inferior valve guides... Dart stopped using CHE, for guides and got some SH;;t soft material... these were heads with Jesel shaft rockers, the guides went to so wide of a clearance it was like for a 3/8 valve, bronze material in oil, had a cylinder head that worked for one of the teams in Charlotte, have the guide tested for hardness, needless to say it did meet spec material... All new guides, back together, never a issue again... Be rest assured, that guide was removed from Darts production, this was like 2005-2006
10-15-2015, 06:34 PM
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10-15-2015, 06:45 PM
#38
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Oh, here you go, had a Profiler Cylinder head have casting flaw, that leaked water, porosity in it. Early years 2004. Had also a Profiler after a new CNC program was done, 3 holes on exhaust bolt holes went into water jacket.... The guy; doing the cnc machining, I called him he shorted the depth of the hole, no big deal, it comes with the job...this was only because they went to a guy in NC that knows his cylinder heads and it was a oversight, in new program, which I know him and he corrected the program ASAP...
I like AFRs for the money and the product. I have used many Profiler , 12 degree, and the CNC Sniper versions, they cost more and were designed by Darren Morgan, as AFRs by Tony Mammo. I haven't used any Brodix, so I can't comment...
I like AFRs for the money and the product. I have used many Profiler , 12 degree, and the CNC Sniper versions, they cost more and were designed by Darren Morgan, as AFRs by Tony Mammo. I haven't used any Brodix, so I can't comment...
10-16-2015, 08:56 AM
#39
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ok fellas lets try to keep this thread on track.what i am looking for is oso members that have had an issue with aftermarket cylinder heads of any brand and what the issue was.i also welcome information from people in the industry who install these heads on engine builds.through the years i have used dart and recently several sets of afr heads.my reason for starting this thread was to gain information about aftermarket cylinder heads.
10-16-2015, 09:12 AM
#40
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I think the bottom line here is that any experienced, professional engine BUILDER, especially in the marine industry, would never assume any set of production heads, from any manufacturer, would be ready to bolt on a marine engine. If a parts-seller sells a part and describes it as "ready to run", and makes his profit on it, then IMO HE is responsible for that part being as described. If it's not, then it's between him and whoever made and shipped the part. This part is not being advertised as a "production, shelf stocking" AFR head, it's being advertised as a special purpose, ready to run marine-specific head and that's what the engine builder should have CONFIDENCE that he's receiving, and is bolting on. If you buy a set of marine specific heads form me, I will GUARANTEE that's what you're getting and while, if you want to dis-assemble them and inspect them if you want, you don't have to because that's what you ordered and that's what you paid for. If the heads should need further work after being received, then that should be clearly disclosed in any agreement between the parts-seller and the end user, be it a retail customer or machine shop/engine builder.
