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  #1  
Old March 21st, 2004, 21:07
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JBrobeck JBrobeck is offline
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Cool Head porting (pictures inside)

I spent an ungodly amount of time cleaning up the intake and exhaust runners on my newly aquired H.O. head, I could not believe how much extra casting there in the runners! it may not look like much material was removed, but it was more extensive than it looks like in the pictures.

I am curious (for my own sanity) to know if all of this work was in vein, or if it will at least net me a little HP/gas milage, I will also be adding the late model equal length runner intake manifold and H.O.throttle body.

Pictures are here...

Intake Ports

Exhaust Ports

View from combustion chamber

Thanks in advance for any input, I can't wait to get this thing up and running again, the New Crane cam, .040 pistons and H.O. conversion ought to be a hoot, hehe, I have a $200 Jeep with a $1000 motor, go figure!

Josh

Last edited by JBrobeck; March 21st, 2004 at 21:08. Reason: fixed picture link
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Old March 22nd, 2004, 04:48
rsalemi rsalemi is offline
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Re: Head porting (pictures inside)

Whats an ungodly amount of time? I spent about 20 hours on mine. A couple of suggestions - do a 3 angle valve job and back cut the intake and exhaust valve and you will pick up the flow even more. as far as improving mileage - thats not what you are accomplishing - you will be making more horsepower (throughout the RPM range but mostly at the high end).
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Old March 22nd, 2004, 07:01
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JBrobeck JBrobeck is offline
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Re: Head porting (pictures inside)

I've got about 14 hours into it right now, and I haven't done the valves yet. I could have had the motor assembled, installed and drivable in half that time, so I was just curious as to if this was really worth my time .

As far as a 3 angle valve job goes, how much would a machinist usually charge for that? I would immagine its not somthing I could do myself as I can't think of any at home valve/seat cutting tools.

When you say back cut the Valves, what does that entail, removing some of the material at the base of the valve?

Sorry if these are dumb questions, but I have never done any headwork before other than lapping the valves during a rebuild

Thanks for you help

Josh
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Old March 22nd, 2004, 10:24
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Re: Head porting (pictures inside)



Looks awesome, i will be doing the same to mine too, can you measure the port sizes and let me know, i am porting my 99 Head and the gasket fits perfectly on the intake ports but the exhaust ports and way small, like my renix head.

Thanks;
Ravi
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Old March 22nd, 2004, 12:07
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Re: Head porting (pictures inside)

You've opened up the ports pretty good there Josh. All you need to do is smooth away the rough spots so that the air takes a smooth flow path and there isn't too much turbulence, especially on the exhaust side. You can leave the intakes a little rough to aid fuel atomization.
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Old March 22nd, 2004, 19:45
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JBrobeck JBrobeck is offline
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Re: Head porting (pictures inside)

Now do I want to go ahead and open up the exhaust ports more or just leave them as is, I don't wanna take away too much bottom end, but If it will really gain me in the top end, it may be worth the effort, I am this far into it and I would really like to do it right ONCE, not have to do it again!

Thanks

Josh
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  #7  
Old March 23rd, 2004, 05:41
rsalemi rsalemi is offline
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Re: 3 angle Valve Job

Find a competent (hard to do) machine shop for the valve job. 3 angle not that much more than standard and if you don't have acces to valve equipment you need to farm it out anyway. Back cutting is removing material from the bottom of the valve (the side in the port - not in the chamber)
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