Intro to a port job

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MOPAROFFICIAL said:
177cc and 175cc-lower head bolt.
Still small, like 'ironbrocks'. lol
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LOL I poured mine and didn't write it down.

I make a spacer to space up that bolt boss on the short bolt. That way I can grind the roofs all the same and the spacer fills in the hole where you break through.

I'll do the same thing on my W2 junk.
 
There are a lot of heads out there that may flow close on all intake ports ...but...they are all over the place in volumes and reflect it in their performance.
 
yellow rose said:
LOL I poured mine and didn't write it down.

I make a spacer to space up that bolt boss on the short bolt. That way I can grind the roofs all the same and the spacer fills in the hole where you break through.

I'll do the same thing on my W2 junk.
Click to expand...

I'm in the process of doing just that for a set I'm working on. I think Mopar used to make a kit to do just this back in the day.
 
yellow rose said:
LOL I poured mine and didn't write it down.

I make a spacer to space up that bolt boss on the short bolt. That way I can grind the roofs all the same and the spacer fills in the hole where you break through.

I'll do the same thing on my W2 junk.
Click to expand...
I do the hard washer in the bolt recess as well. These I want to be 'zero problems' or '100% reliable without a doubt' 'to last like OEM' for Randall. Not that the washers become an issue, just that this is not a max effort port job. We are about waist deep. 10 more cfm would be chest deep... and you gotta ask if you handle the disappointment if it hits a water jacket or head bolt..
skrews said:
I'm in the process of doing just that for a set I'm working on. I think Mopar used to make a kit to do just this back in the day.
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I do that too. These heads are meant to be as reliable as OEM without a doubt, nothing special needed , and the last thing to blame if something fails.. lol
I'm not sure how thick or thin the ports are, while they seem the more meatier heads cast by weight.. that could be in the shell, rails ,deck and not the ports. Who knows. I have a set of 915 J that have the washers in..they are more a max effort started out as not caring if I put holes into them...they are huge ports..they were a 'point maker' for me aimed at all the nay sayers of the time..
They still put most peoples heads to shame, across the board for a 2.02.
 
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Jadaharabi said:
Did the machine shop mill the heads to flatten them?
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Yep, that's included in the head service. Figure out what they are after the valve job then mill to desired cc.
For others reading and learning.. your average set of 72cc 1.88 valve 360 heads ..shrink by a couple cc's-aka get smaller after the 2.02 upgrade. Take another .025 off and these would be what, 65cc, thats not much to take off, do another .015 off the intake side which is a hair less than formulated but would be enough to fit the intake.
 
EXHAUST.
No before numbers, they all flow 132-145cfm stock anyway.
I'm in the middle of testing and touching up the exhaust. Some were short 10 cfm from what i was looking for so i did a little blending of the lower angle to short turn, left the angle alone around the bowl. They dont need to be pretty to work good, not polished, smoothed, but no sand rolls or shine.
It flowed w/no pipe and prior to touch up..as follows..
@28" 4" BORE 1.60 valve
Lift-cfm
.2-110
.3-144
.4-160
.5-166
.6-171

New numbers after touch up.
@28" 4" bore no/pipe
no pipe-
Lift....cfm
.200-110
.300-144
.400-160
.500-179
.600-186
And w/1 3/4 x 10" pipe.
Lift....cfm
.200-109
.300-150
.400-170
.500-190
.600-197

At really low lifts the pipe doesn't do much, as you can see from the numbers, but after the valve opens... the pipe carries the velocity 'just like your header tube does' and the numbers jump. Without it...the front of the air stream expands out of the port window ,slows and then the rest of the stream crashes into it. Fwiw. This is an end port, like .1,2,7,8 exh port. Pics sucks, sorry.

20200217_114034.jpg


20200217_112502.jpg
 
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The cross over port, which would be cyl 4 or 5 exhaust port, is really fun to work with..
It either flows behind all the others at peak by 10 cfm...or if you pull the tape off the cross over side , flows better.
ATM its stuck at [email protected] w/pipe.
All the low numbers are within 4cfm less ,closest spread is 1 or 2 cfm in the .300-.400 then they make a really bitchin sound ...like blowing over a bottle with compressed air with the sound frequency breaking up @.450.. lol
 
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I dont have his intake manifold to know what it really flows from carb to valve to assume the exact int/exh flow ratio.
Taking it as is, 72-75% ish
But ill guess with an intake ootb intake it gets better.
 
Last exh on that head w/pipe
.2..108.2
.3..150.5
.4..176
.5..194
.6..202
The other head exh #'s
.2..113....112....112....114
.3..154....150....153....150.2
.4..180....174....180....175.4
.5..190....187....190....186.5
.6..201....194....197....197
Core shift is in the numbers, interesting.
When the blower motor heats up, the numbers drop a little. If you let it cool...I think the lower numbers would be about the same.
The last intake numbers were tested using about an ugly 1/2" clay radius. I sprung for some new clay and made a nice 1" uniform clay radius and the party got bigger.
....Overall avg with actual 1 inch clay radius @28" w/ 4" bore adapter
......Int/exh
.1..65.2......
.2..130..110
.3..192..152
.4..244..178
.5..268..190
.53..269 194
.6..267..200

Knocking on 270cfm ...these are just some smogger heads off a 70's van. Gotta love mopar.

20200307_181636.jpg
 
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Sure look a lot better than the 308 sunk valve heads I shipped you.
These heads are using the same 11/32 2.02-1.60 SS Edelbrock valves also.
I think they should work great with my .508 cam in my .060 over 340.

Post some finished pictures.
 
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Jadaharabi said:
Sure look a lot better than the 308 sunk valve heads I shipped you.
These heads are using the same 11/32 2.02-1.60 SS Edelbrock valves also.
I think they should work great with my .508 cam in my .060 over 340.

Post some finished pictures.
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Will post some more.
Btw that last pic IS a finished port.
For those watching...I did initial port work, sent them off for a valve job, did not approve of said valve job...testing even showed...so i took them to my other guy who did it right. Tested them again with big improvements to all but with some needing attention with air speed issues. I widened up the area between the guide and head bolt some more on those with the low head bolt pad and thinned the push rod hole a lil more, which did help. I also exploited the cast in swail just a hair, to help speed the common wall side of the turn, equalize the middle more..as well as a angled lip where the turn comes off the common wall. Hard to explain and odd sounding I'm sure.
 
MOPAROFFICIAL said:
Will post some more.
Btw that last pic IS a finished port.
For those watching...I did initial port work, sent them off for a valve job, did not approve of said valve job...testing even showed...so i took them to my other guy who did it right. Tested them again with big improvements to all but with some needing attention with air speed issues. I widened up the area between the guide and head bolt some more on those with the low head bolt pad and thinned the push rod hole a lil more, which did help. I also exploited the cast in swail just a hair, to help speed the common wall side of the turn, equalize the middle more..as well as a angled lip where the turn comes off the common wall. Hard to explain and odd sounding I'm sure.
Click to expand...


And that is why you TEST. If you don’t test you don’t know.

Very cool MO.
 
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