Some "Dynomite" Heads! - Page 4 - ZR-1 Net Registry Forums

tomtom72 · 01-06-2011

Thank you Bob. I have just always wanted to know what all the terminology meant. I'm not going to become a cutter & a polisher any time in the future. It's just nice to be able to follow all the conversations that all you guys have and have a clue what you guys are talking about.

Paul Workman · 01-16-2011

Uh...Say there, Bob! Bout time for some eye candy and an update on dem heads progress, yes?

P.

Locobob · 01-16-2011

Yep time for an update

Here we have both primary and secondary intake ports opened up to approx 35mm down as far as the valve guide boss. Primary is close to 36mm at the top and secondary still around the factory 36.5mm at the top. Note the ring left by the factory machining process around the secondary port just below the butterfly location. It was machined by the factory to about 36.5mm down to this ring after which they did a quick machine blend reducing the port to about 32mm in just a half inch or so.

Secondary port with telescoping gauge set at 35mm in three locations, still a fairly large change with the port now at 35mm. Obviously the butterfly assembly takes up some of the extra volume at the top of the port.

Locobob · 02-04-2011

Been fine tuning the intake runners and matching to the injector housings.

I've been using a template to align the ports, now it's time to bolt the parts together and fine tune the match.

This is a 3/4in tall sanding sleeve mounted on a 1/2in tall rubber drum - allows a little flex to get into the curve areas at an angle.

Drum sander on a long mandrel, bend-o-light through the injector boss for lighting.

After working the port around the mating surface with the drum I switch to a flap wheel to finish it off.

Locobob · 02-04-2011

Looking down the primary port, can you find the gasket surface between the two parts?

And the secondary port. You can see the mating surface line on these, someone went a little overboard on the factory match and I didn't want to get crazy enlarging them to get rid of the tiny lip they created.

Looking up the primary from the combustion chamber side.

And same view for the secondary port.

Aurora40 · 02-04-2011

Looks good!

FU · 02-04-2011

Again , very nice work Rob !
Now some may understand the time and effort that need's to be put into porting the top end of an LT5.

tomtom72 · 02-04-2011

Quote:

Originally Posted by FU2

Again , very nice work Rob !
Now some may understand the time and effort that need's to be put into porting the top end of an LT5.

"Amen" to that thought Frank!

Bob, I kind of thought I had an idea about just how much fine detail work was involved, but now I really have a better grasp of the work involved. Thanks for the time it takes to share this with us!

Paul Workman · 02-04-2011

Quote:

Originally Posted by Locobob

Looking down the primary port, can you find the gasket surface between the two parts?

Smmmmooooooth! Yeah, it is amazing just how abrupt many of the joint and especially the so-called "taper" below the secondary throttle plate is as the system comes from the factory. I recon that is why these motors respond so very well to a little TLC in the runners.

Beautiful work, Bob.

P.

sammy · 02-04-2011

all i can say is that this is the best work i have ever seen on a set of heads the atten to detail second to none .thankyou for sharing , this stuff is art .

01-06-2011	#31
tomtom72 Join Date: Dec 2004 Location: Jacksonville, FL USA Posts: 4,645	Re: Some "Dynomite" Heads! Thank you Bob. I have just always wanted to know what all the terminology meant. I'm not going to become a cutter & a polisher any time in the future. It's just nice to be able to follow all the conversations that all you guys have and have a clue what you guys are talking about. __________________ 1990 ZR-1, Black/grey, #2233, stock. ZR-1 Net Reg Founding Member #316 & NCM member

01-16-2011	#32
Paul Workman Join Date: Nov 2007 Location: Squires (near Ava MO in the Mark Twain N'tl Forest) - Missouri Posts: 6,493	Re: Some "Dynomite" Heads! Uh...Say there, Bob! Bout time for some eye candy and an update on dem heads progress, yes? P. __________________ Good carz, good food, good friendz = the best of timez! 90 #1202 "FBI" top end ported & relieved Cam timing by "Pete the Greek" Sans secondaries Chip & dyno tuning by Haibeck Automotive SW headers, X-pipe, MF muffs Former Secretary, ZR-1 Net Registry

01-16-2011	#33
Locobob Join Date: Jan 2004 Location: Portland, OR Posts: 1,057	Re: Some "Dynomite" Heads! Yep time for an update Here we have both primary and secondary intake ports opened up to approx 35mm down as far as the valve guide boss. Primary is close to 36mm at the top and secondary still around the factory 36.5mm at the top. Note the ring left by the factory machining process around the secondary port just below the butterfly location. It was machined by the factory to about 36.5mm down to this ring after which they did a quick machine blend reducing the port to about 32mm in just a half inch or so. Secondary port with telescoping gauge set at 35mm in three locations, still a fairly large change with the port now at 35mm. Obviously the butterfly assembly takes up some of the extra volume at the top of the port. __________________ Robert ZR-1 Net Registry Oregon State Director 91 ZR-1 #431 Black/Black LPE 368

02-04-2011	#34
Locobob Join Date: Jan 2004 Location: Portland, OR Posts: 1,057	Re: Some "Dynomite" Heads! Been fine tuning the intake runners and matching to the injector housings. I've been using a template to align the ports, now it's time to bolt the parts together and fine tune the match. This is a 3/4in tall sanding sleeve mounted on a 1/2in tall rubber drum - allows a little flex to get into the curve areas at an angle. Drum sander on a long mandrel, bend-o-light through the injector boss for lighting. After working the port around the mating surface with the drum I switch to a flap wheel to finish it off. __________________ Robert ZR-1 Net Registry Oregon State Director 91 ZR-1 #431 Black/Black LPE 368

02-04-2011	#35
Locobob Join Date: Jan 2004 Location: Portland, OR Posts: 1,057	Re: Some "Dynomite" Heads! Looking down the primary port, can you find the gasket surface between the two parts? And the secondary port. You can see the mating surface line on these, someone went a little overboard on the factory match and I didn't want to get crazy enlarging them to get rid of the tiny lip they created. Looking up the primary from the combustion chamber side. And same view for the secondary port. __________________ Robert ZR-1 Net Registry Oregon State Director 91 ZR-1 #431 Black/Black LPE 368

02-04-2011	#36
Aurora40 Join Date: May 2005 Location: Leesburg, VA Posts: 2,713	Re: Some "Dynomite" Heads! Looks good! __________________ Bob Saveland Former owner of #2517 [IMG]http://a.random-image.net/aurora40/vette.jpg[/img]

02-04-2011	#37
FU Join Date: Mar 2004 Location: Found Member Posts: 4,346	Re: Some "Dynomite" Heads! Again , very nice work Rob ! Now some may understand the time and effort that need's to be put into porting the top end of an LT5.

02-04-2011	#40
sammy Join Date: Jun 2010 Location: back in lone pine Posts: 591	Re: Some "Dynomite" Heads! all i can say is that this is the best work i have ever seen on a set of heads the atten to detail second to none .thankyou for sharing , this stuff is art .