anybody got a spare all pro 6 bolt head?
04-07-2010, 07:41 AM
#41
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I remember a thread from a while ago where Noyzee had a set of AFR 225s he had the water holes on the deck welded up. The head kept cracking and getting repaired. He sent off to Tony Mamo who noticed the welding and ran some hardness / rockwell tests on it. I don't remember the percentage drop in hardness compared to an out of the box AFR head Noyzee's head tested at, but it was a considerable amount.
With the heat produced welding on a head the rockwell rating should drop. I've never welded on a head so I have no idea of the heat necessary to produce a weld so this may be mute, but any time you are physically rearranging the molecules in a substance the object will not be the same. Localizing heat can be difficult (again, haven't tigged on a head before). That heat causes things to shift and can cause seats, guides, etc.. to move. David, did you have the seat issue with these heads before or after the repair on the heads?
Tony mentioned you can weld on a head as long as the seats, guides are pulled and the head is put through a rehardening process. With the amount of issues you've had and I'm guessing you will have in the future I think it would be a wise investment to purchase a new set of heads. This is no bash against Bob's products either as I used to own a set of gen I cathedral port all pros before I had to sell them. Bob puts out a great product and has great service. Were these heads still as cast / light cleanup work around the guides? If so I'd take All Pro up on their casting offer and have them run their 255ish cc drag port through the head.
Good luck.
With the heat produced welding on a head the rockwell rating should drop. I've never welded on a head so I have no idea of the heat necessary to produce a weld so this may be mute, but any time you are physically rearranging the molecules in a substance the object will not be the same. Localizing heat can be difficult (again, haven't tigged on a head before). That heat causes things to shift and can cause seats, guides, etc.. to move. David, did you have the seat issue with these heads before or after the repair on the heads?
Tony mentioned you can weld on a head as long as the seats, guides are pulled and the head is put through a rehardening process. With the amount of issues you've had and I'm guessing you will have in the future I think it would be a wise investment to purchase a new set of heads. This is no bash against Bob's products either as I used to own a set of gen I cathedral port all pros before I had to sell them. Bob puts out a great product and has great service. Were these heads still as cast / light cleanup work around the guides? If so I'd take All Pro up on their casting offer and have them run their 255ish cc drag port through the head.
Good luck.
I'm pretty sure shawn has the capability to heat-treat...
04-09-2010, 09:43 PM
#48
Awesome. Hope they hold up for ya. Real curious to see what kind of gains you get from the new front cover/wheel on the turbo.
I'm curious, how much pressure were you having to put on the back of the gate to run the 8.6 number? I have a really soft spring in mine but I am having to put 30 psi to the gate to make 19psi. Not sure if it's too much backpressure in the exhaust, a very small boost leak or something not right inside the turbo. I don't think that a 7 psi spring + 30 psi of CO2 should only be yielding 19 psi of boost.
I'm curious, how much pressure were you having to put on the back of the gate to run the 8.6 number? I have a really soft spring in mine but I am having to put 30 psi to the gate to make 19psi. Not sure if it's too much backpressure in the exhaust, a very small boost leak or something not right inside the turbo. I don't think that a 7 psi spring + 30 psi of CO2 should only be yielding 19 psi of boost.
04-10-2010, 01:42 AM
#51
i got a ticket tonight.. figures... lol
answer.. i dont have c02 or that stuff.
i dont know how much boost the eboost2 diverts to the back of the gate but it has to be equal or less than the 24# boost made.
my gate will run as low as 12# on the spring.. so i figure im adding another 12# behind it to get 24??
answer.. i dont have c02 or that stuff.
i dont know how much boost the eboost2 diverts to the back of the gate but it has to be equal or less than the 24# boost made.
my gate will run as low as 12# on the spring.. so i figure im adding another 12# behind it to get 24??
04-10-2010, 01:50 PM
#53
Heat treating is not a simple process. I haven't seen many service shops with this capability. Normally it is a manufacturer process, big ovens, controlled temperature over time, special quenching process based on metallurgy, etc. to be 100% effective. Most heads that get repaired at our shop are not re-heat treated. In fact, I will go on a limb and say that 80% or better in this trade are not re-heat treating a repaired aluminum head or block. Many of these repairs work just fine.
Ran that head for several years after I repaired it. Sometimes you just don't have a choice.
Ran that head for several years after I repaired it. Sometimes you just don't have a choice.
04-10-2010, 06:50 PM
#54
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Awesome. Hope they hold up for ya. Real curious to see what kind of gains you get from the new front cover/wheel on the turbo.
I'm curious, how much pressure were you having to put on the back of the gate to run the 8.6 number? I have a really soft spring in mine but I am having to put 30 psi to the gate to make 19psi. Not sure if it's too much backpressure in the exhaust, a very small boost leak or something not right inside the turbo. I don't think that a 7 psi spring + 30 psi of CO2 should only be yielding 19 psi of boost.
I'm curious, how much pressure were you having to put on the back of the gate to run the 8.6 number? I have a really soft spring in mine but I am having to put 30 psi to the gate to make 19psi. Not sure if it's too much backpressure in the exhaust, a very small boost leak or something not right inside the turbo. I don't think that a 7 psi spring + 30 psi of CO2 should only be yielding 19 psi of boost.
With a 10lb actual gate only boost pressure (I don't know what the actual gate spring is rated at..doesn't really matter...I get 10psi in the manifold gate only for reference).....I add 12psi of CO2 to get 18.5psi in the manifold. Just a data point for ya.
04-12-2010, 07:32 PM
#58
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Glad the head is working for you David.
We have learned alot over the years about aluminum repair from both top cylinder head repairers and experience.
most people do a few things wrong that lead to improper repairs.
incorrect surface prep-the don't remove enough material to get rid of the affected/weak area.Thet want to v goove a crack and a little wire brush.You need to remove all the damaged material to get to a good base.
improper welding techniques-wrong welding gas,fill wire,not enough heat and or just using too small of a welder.
improper post treatment of the piece that was repaired.
We have learned alot over the years about aluminum repair from both top cylinder head repairers and experience.
most people do a few things wrong that lead to improper repairs.
incorrect surface prep-the don't remove enough material to get rid of the affected/weak area.Thet want to v goove a crack and a little wire brush.You need to remove all the damaged material to get to a good base.
improper welding techniques-wrong welding gas,fill wire,not enough heat and or just using too small of a welder.
improper post treatment of the piece that was repaired.
