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Old 12-20-2010   #1
Locobob
 
Join Date: Jan 2004
Location: Portland, OR
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Default Some "Dynomite" Heads!

Just getting started on Dynomite's head porting so I thought I'd share as I go along. Some interesting measurements from the stock (untouched) heads:

Combustion Chambers came in around 41cc with not much deviation, this was using my own method and a spark plug in the hole.

Intake runner dimensions:
Diameter at IH gasket surface: Primary 32.3mm, Secondary 36.4mm
Diameter, narrowest point of runner: Primary 32mm, Secondary 32mm (just upstream of valve guide)
Runner width at valve guide: Primary 33mm, Secondary 33mm
Valve seat diameter: Primary 34.7mm, Secondary 34.7mm

Exhaust port dimensions:
Valve seat diameter: 32mm
Width across valve guide: 34.8mm
Runner narrowest point: 31.5mm (where ports merge into one)
Header gasket surface: 51.8mm long, 35.6 tall
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Old 12-20-2010   #2
Locobob
 
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Default Re: Some "Dynomite" Heads!

Some close ups of the chambers:







The worst areas are hard to see, sharp edges and poor transitions an inch or so above the valve seats.
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Old 12-20-2010   #3
Locobob
 
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Default Re: Some "Dynomite" Heads!

Looking down the intake runners:
It would appear from the measurements I made that the two runners are mirror image castings with only the machining done to the top of the secondary port differentiating them.



Exhaust ports:



Here is the template I made off the bottom of the injector housings which I had enlarged only slightly. You can see just how skewed the port alignment is from the factory. It is noticeably worse on the primary runners, secondaries are closer probably due to the machine work done on these.



And marked on the head without the template

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Last edited by Locobob; 12-20-2010 at 01:08 AM.
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Old 12-20-2010   #4
mgbrv8
 
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Default Re: Some "Dynomite" Heads!

Excellent work Sir, keep the pictures coming.
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Old 12-20-2010   #5
Kevin
 
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Default Re: Some "Dynomite" Heads!

glad to see your heads getting some love
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Old 12-21-2010   #6
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Default Re: Some "Dynomite" Heads!

( insert wolf whistle here ) It's nice to see your car getting some head work dunn


Tom
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Old 12-21-2010   #7
A26B
 
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Default Re: Some "Dynomite" Heads!

Great pictures Bob. When I first started making gaskets, I used LT5 engine drawings & made them to that spec. Scared the bejesus out of me when I check fit to early style engine parts.

Looking forward to seeing the entire series, all the way to the finish line.
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Old 12-21-2010   #8
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Thumbs up Re: Some "Dynomite" Heads!

Quote:
Originally Posted by A26B View Post
Great pictures Bob..

Looking forward to seeing the entire series, all the way to the finish line.
Agreed
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Old 12-21-2010   #9
RICKYRJ1
 
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Default Re: Some "Dynomite" Heads!

Thanks for the starting info! Dynomite is getting good head . Locobob gave me a great education in porting & cleared up a lot of misinformation that I had., Dyno will be more than happy with the work. Keep this thread updated with you progress.
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Old 12-28-2010   #10
A26B
 
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Default Re: Some "Dynomite" Heads!

I'm gonna cut those heads up in single cylinder chunks, with the cam cover installed, have 'em signed by Bob Hall, Pete P., and some other famous members and sell 'em for about a zillion bucks each so I can retire.

Seriously, it takes quite a few sections to see everything that is of concern for full boogie head porting.
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1994 ZR-1, Black/Black, Lingenfelter Aerobody, 416cu in, 3.91 gears, coil-over susp, Brembo brakes, etc.
2016 Black-Red, 3LT-Z51 Auto 8-speed.
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