Afr Heads
Thread Starter
Racer
Joined: May 2004
Posts: 270
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From: NORFOLK VA.
Afr Heads
Ok the engine is 1500 miles old I did a cylinder leakage test I am getting 10 to 22% leakage so I sprayed a little soapy solution in the exhaust with the leak detecter hooked up and it blew the solution out, all the exhaust valves are doing this has anybody else had this happen with afr heads and if so what caused it. 
Race Director
Joined: Aug 2000
Posts: 11,506
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From: Vancouver,Wa.
Originally Posted by MR.KIDD
Ok the engine is 1500 miles old I did a cylinder leakage test I am getting 10 to 22% leakage so I sprayed a little soapy solution in the exhaust with the leak detecter hooked up and it blew the solution out, all the exhaust valves are doing this has anybody else had this happen with afr heads and if so what caused it.
Race Director
Joined: Feb 1999
Posts: 12,772
Likes: 17
From: Indianapolis IN
Originally Posted by Corvette0096
I have a brand new set that just came in from AFR. I bought the comp 195 100% CNC. Get this 10 Bad valve guides. Not bad for a $2200 head. Race shop is pissed, Then they sent just the standard Valves too..I think AFR quality is going to hell. They must be pushing the hell out of the guys there to meet there quotes.
I am little suprised, but not really
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
Originally Posted by Corvette0096
I have a brand new set that just came in from AFR. I bought the comp 195 100% CNC. Get this 10 Bad valve guides. Not bad for a $2200 head. Race shop is pissed, Then they sent just the standard Valves too..I think AFR quality is going to hell. They must be pushing the hell out of the guys there to meet there quotes.
A while back someone on this Forum posted photos of a set of AFR heads that showed the casting covered with pot marks (or is it pock marks). Porosity in the casting. AFR exchanged the heads, but that didn't explain away the absence of quality control.
On another board, someone else detailed all the quality control issues he had with a pair of new AFR heads. I'll bet that if you do some checking, you'll find many other examples of the same thing.
For some reason many seem all to eager to forgive AFR for these quality control failures. Having ports that flow like crazy is NO substitute for the problems these heads have been shown to have.
Jake
Safety Car
Joined: Feb 1999
Posts: 3,504
Likes: 4
From: Mexico Beach FL
Originally Posted by MR.KIDD
Ok the engine is 1500 miles old I did a cylinder leakage test I am getting 10 to 22% leakage so I sprayed a little soapy solution in the exhaust with the leak detecter hooked up and it blew the solution out, all the exhaust valves are doing this has anybody else had this happen with afr heads and if so what caused it.
I put AFR heads and a Crane cam in. As soon as I had it together, I did a leak-down test on a cold engine -- with my LT1, there is no way I am going to get all 8 plugs out while the engine is still warm.
I had about 15% leakage, and I could hear the air hissing from the intake and exhaust. I felt sure it was the valves. Then, I put some oil in the cylinders and turned the engine over by hand before doing another leak-down test. This time my leakage dropped to less than about 7%. Most of my leakage was past the rings, but heard the most noise from the valves.
I then called AFR about the hissing I could hear past the valves, they told me they do not lap valves in because there is no way to get **all** the grinding compound out. He told me, no matter how good you think you are at cleaning it afterwards, there will still be some compound left. Their opinion was it was better to not lap the valves because they would seat-in on their own.
No porosity problems wiht my castings, they looked great.
That was about seven years and 40,000 miles ago, and I have never had the engine apart since.
Tom Piper
Last edited by Tom Piper; Aug 24, 2004 at 06:27 AM.
Le Mans Master
Joined: Feb 2000
Posts: 9,715
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From: Kempner Texas
[SNIP=Tom Piper]
No porosity problems wiht my castings, they looked great.
That was about seven years and 40,000 miles ago, and I have never had the engine apart since.Tom Piper[/SNIP]
The porosity problem only reared it's ugly head when the owner had the heads surfaced. They "looked" fine out of the box, but once surfaced you could see the casting had what looked like hundreds of little holes in it.
Jake
No porosity problems wiht my castings, they looked great.
That was about seven years and 40,000 miles ago, and I have never had the engine apart since.Tom Piper[/SNIP]
The porosity problem only reared it's ugly head when the owner had the heads surfaced. They "looked" fine out of the box, but once surfaced you could see the casting had what looked like hundreds of little holes in it.
Jake
Thread Starter
Racer
Joined: May 2004
Posts: 270
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From: NORFOLK VA.
Thanks for the replys guys I am going to have the local head guru around here(Bob Evans) in Newport News Va. check them out first before I send them back that way when I send them back they willnot be able to bs me about whats wrong with them. 
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Drifting
Joined: Aug 2001
Posts: 1,500
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From: Holliston MA
Cruise-In VII Veteran
They'll blame it on improper valvetrain geometry and have your heads and you over a barrel. If Bob Evans is the guru you say he is, when he checks out your heads have him fix the problems and put AFR long behind you.
If you ask AFR, there are no problems with their heads. Ask Mr. Evans what he thinks about their heads, other than the ports.
AFR is on the bottom of my list, when it comes to cylinder heads.
If you ask AFR, there are no problems with their heads. Ask Mr. Evans what he thinks about their heads, other than the ports.
AFR is on the bottom of my list, when it comes to cylinder heads.
Le Mans Master
Joined: Feb 2000
Posts: 9,715
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From: Kempner Texas
Originally Posted by vsocks
Who is on the top of the list for aftermarket heads?
It's those companies that have the financial resources to invest in the latest equipment (and keep it calibrated), highly trained, dedicated personnel and rigid quality control checking/verifying procedures to ensure repeatable, extremely accurately machined products come out of their factory.
Stick the the big names; names you can immediately recognize and can trust.
Jake
Drifting
Joined: Aug 2001
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From: Holliston MA
Cruise-In VII Veteran
Originally Posted by vsocks
Who is on the top of the list for aftermarket heads? I have some L98 113 heads that I will build/mod or just sell and buy aftermarket.
The 113 heads can be worked nicely, and they came off a corvette to begin with. There shouldn't be any major geometry issues.
Are you willing to change valve covers ? If you are willing to go with a perimeter valve cover the choices become almost endless.
