318 head porting for the average joe

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ken5124 said:
need your help wild and crazy guy ! duplicating this question from my restoration thread

Working a freshening up my 318 646 heads, motor has 14 thousand KM's on it.. built by an engine shop 10 years ago.

Motor is apart and I pulled the valves from 1 cylinder to look them and the ports over.


On The exhaust valve, the seal had ridden up inside the valve spring.. not on tight on the base as the intake size was.. Is that wrong?

2nd question I had to use a center punch to push the exhaust valve out of the head, really had to use a lot of force to remove it. small bits of brass left in the valve lock grooves when it came out.

Is that normal ?.. Intake valve popped out no problem.??




3rd and final for today What do you think caused the build up on this intake valve.. This motor has 14 thousand KM's on it. I know it was running rich for many of those miles prior to dialing it in with wideband air/fuel setp.

Thanks ! Ken
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That is burnt oil and fuel deposits on the back Side of the valve, umbrella seals??...see positive seals press onto the guide boss and control the oil better...but I'd say that the guides and or valve stems r probably shot cause the int is sucking oil.
FWIW Umbrella seals ride on the valve and let oil get sucked into the guide easier.
Next time u remove valves....1st run a file around the lock groove cause u just carved out the bronze sleave.
 
Justin,would be interested in tweaking stock crack free Magnum castings?
 
Let me p.m. you,info.Justin might take me a couple of days,thanks for the response.
 
1wild&crazyguy said:
That is burnt oil and fuel deposits on the back Side of the valve, umbrella seals??...see positive seals press onto the guide boss and control the oil better...but I'd say that the guides and or valve stems r probably shot cause the int is sucking oil.
FWIW Umbrella seals ride on the valve and let oil get sucked into the guide easier.
Next time u remove valves....1st run a file around the lock groove cause u just carved out the bronze sleave.
Click to expand...

THanks.. One bronze sleave shot for sure.... Will use the file method for any others instead of brute force.

Appreciate this post and your help.. !
 
Been playing some with my heads and porting . Cleaned up the bowl on one intake and widened my ports to match the gaskets.

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318 Head Porting 106-4.JPG
 
thats a good start, but theres something you should know about opening the push rod side of the port window up to the gasket, see...u create this narrow to wide to narrow spot which just slows the air down, and really...the push rod pinch at the level we're talkin here does not hinder air flow.
What i recommend is 'if at all' grind the push rod bulge as thin as possible without getting too thin then open the port window on that side to that and no more. on my 360/340 port jobs i never open the window to the push rod side of the gasket cause the pinch is where 'if any' restriction is, so its fruitless messing with the window on the side.
u dig?
 
Appreciate that Thanks. I thought I would be helping the flow somewhat because I have a Mopar aluminum intake ( much larger port) and I felt the flow would be hitting a wall, so to speak.. It was almost 3/16 th of an inch smaller than my intake on that side.
 
ken5124 said:
Appreciate that Thanks. I thought I would be helping the flow somewhat because I have a Mopar aluminum intake ( much larger port) and I felt the flow would be hitting a wall, so to speak.. It was almost 3/16 th of an inch smaller than my intake on that side.
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So you arent running a performer im guessing?
Well in your case i can see why you'd want to do that.
A lot of intakes are 360 port windowed, though they are on the small side for the 360 head port window, are a lot larger than a 318 port window.
 
Those are good numbers. I flowed my 340 X heads after removing the casting flaws, rounding edges and polishing the exhaust. My numbers were 238cfm int and 178cfm exh.
Good work and nice thread!
 
Need some more guidance. I have been continuing to work the one intake port shown in previous post. Using the floating pressure drop system that David Vizard details in his book, I have produced an improvement at.500 lift of 19%. Sorry no CFM numbers with this simple flow setup..

The tail of the valve guide.. Is their benefit to grinding it flush at the far end deep in the port?

Can you tell me or show me where the water around the guide and bowl is? I presume it is around the guide and pocket area..from my measurements with calipers, I think I have .22 of an inch in the roof at the skinniest part. I want to work the top a bit , up into the tail of the guide.

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I am also wondering if I should grind a bit to avoid Valve Shrouding? as marked with black marker and indicated by the caliper. Looks like I could bevel the edge about 1/16th inch back.

I am using the 1.88 valves on this 646 head. Sorry for the fuzzy picture.

Thanks , Ken

318 Head Porting 113-1.JPG


318 Head Porting 113-2.JPG
 
Need some more guidance. I have been continuing to work the one intake port shown in previous post. Using the floating pressure drop system that David Vizard details in his book, I have produced an improvement at.500 lift of 19%. Sorry no CFM numbers with this simple flow setup.

hey ken5124 could you plz post name etc of book you mention
 
Sure

David Vizard is the author.. "how to Port and flow test Cylinder heads "

Printed by s a designs

Got it off Amazon for 19 bucks GREAT read.
 
Ken, about unshrouding...... you need to do this...put the heads on the bare block with each marked L & R ..then from the bottom of the cylinder use a scribe and trace the bore size onto the head, then grind to that with the head back off on the bench ;)

Here is an example with one of my j heads for my stroker..

318 Head Porting 116-1.JPG
 
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yrs and i never googled how to draw lines to simplify describing where to port..lol
Work the straight wall/short turn and widen this area for more flow increase.

btw im on a macbook...so its hard to draw a nice line with this pad.lol

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318 Head Porting 118-2.JPG
 
i am going to start on my J's tonight, mainly just wanting to port match to my air gap. Any tips on opening the port size up towards the pushrod? not much room to work there
 
aaron68s said:
i am going to start on my J's tonight, mainly just wanting to port match to my air gap. Any tips on opening the port size up towards the pushrod? not much room to work there
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With the 318 port u can open it up to about flush with the valve seat if u wanted to.
I would leave just a hair of trasition to the seat.
Air lke the straightest path.
 
aaron68s said:
i am going to start on my J's tonight, mainly just wanting to port match to my air gap. Any tips on opening the port size up towards the pushrod? not much room to work there
Click to expand...

I wouldn't do anything other than thin the pushrod buldge as much as u can, opening it to the gasket at the port window entrance does not help cause the push rod pinch is still there right afterwards. See if the intakes port windows are wider to start, only open the them up to the divider wall part of the gasket is my advice...though if they are wider on the pinch side..then just open the heads window to them as is and no more. Jmo
 
1wild&crazyguy said:
I wouldn't do anything other than thin the pushrod buldge as much as u can, opening it to the gasket at the port window entrance does not help cause the push rod pinch is still there right afterwards. See if the intakes port windows are wider to start, only open the them up to the divider wall part of the gasket is my advice...though if they are wider on the pinch side..then just open the heads window to them as is and no more. Jmo
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so dont open the pushrod side of the window out to the gasket, just the divider wall side?
 
aaron68s said:
so dont open the pushrod side of the window out to the gasket, just the divider wall side?
Click to expand...

thats my opinion on it, cause when you do...it go's from narrow to wide and then narrow again cause of the push rod pinch that you cant avoid in factory castings without tubing. so opening that side to the gasket is like pointless to me. The j heads in the pick above do not have the window opened on the push rod side, just thinned the pinch...and they flow 280's, so much for needing the window matched all round.lol:happy1:
 
And ken, you need to clean up that port window, and straighten the roof from the window cause it looks like a speed bump, you can see the restriction just past the window mod...and thats what is now a choke.
 
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