Some "Dynomite" Heads! - Page 9 - ZR-1 Net Registry Forums

Polo-1 · 04-01-2011

if you look in the port of GVD vs Rob's you will see it.

It's the old knife edge or flat edge debate.

XfireZ51 · 04-01-2011

Yes, I noticed that in my heads. Port divider has a flat edge to it.

Locobob · 04-02-2011

After tiptoeing around the valve seats working the chambers I finally got smart and had my local machine shop cut me some junk valves to use for protecting the seats. I think they came from a Toyota or something but anyhow I had them cut so that they fit almost perfectly flush with the chamber roof. Wish I had done this earlier - makes the job so much easier.
Here are some pics of the chamber work coming along.

Polo-1 · 04-02-2011

you might be on to something Rob " under sized valves "

Locobob · 04-07-2011

Almost done, just some fine tuning to do.

Polo-1 · 04-07-2011

a little more polish and they will be ready to hang on the wall

They look really nice Rob.

tomtom72 · 04-07-2011

I have to stop looking at your work Bob or I will start to hate my stock ZR-1.....which I used to be extremely happy with I might add!

Man that is just some fine head work! I have head envy!

FU · 04-07-2011

Stock is boring Tom. Take a ride to Chicago

Locobob · 04-09-2011

Quote:

Originally Posted by FU2

Stock is boring Tom. Take a ride to Chicago

Headers, exhaust and porting really wake up the motor and let the 32 valve design shine.

Locobob · 04-09-2011

CC ing again. I did this before starting just to establish a baseline but now the focus is on chamber to chamber consistency. Anyhow the my results after working the chambers came in at a smallest of 41.5cc and a largest of 42.5cc. I do each chamber twice as an error check, if I see any substantial difference then I do it over until I get a consistent result. My method has proven to be accurate and repeatable, I figure my margin of error is probably under .5cc. The largest volume was the chamber I used to make my template - which I expected as it shows the difference between the template and the marker trace on the others. The next step is to remove some more material to bring all the chambers up to the volume of the largest.

Here we have a chamber filled with water and a bit of food coloring. The plate over the top is 1/2in plexi with some Vaseline around the edges and valves for sealant.

How much difference is 1cc? About 2.4%
Here is 1cc poured into the corner of a chamber - probably looks like more than it is since the head is tilted. Anyhow when I'm done they will all be at 42.5cc and then the heads will be surfaced to achieve the desired compression ratio.

04-01-2011	#81
Polo-1 Join Date: Sep 2005 Location: Washington Posts: 955	Re: Some "Dynomite" Heads! if you look in the port of GVD vs Rob's you will see it. It's the old knife edge or flat edge debate.

04-01-2011	#82
XfireZ51 Join Date: May 2007 Location: Chicagoland, IL Posts: 9,708	Re: Some "Dynomite" Heads! Yes, I noticed that in my heads. Port divider has a flat edge to it.

04-02-2011	#83
Locobob Join Date: Jan 2004 Location: Portland, OR Posts: 1,057	Re: Some "Dynomite" Heads! After tiptoeing around the valve seats working the chambers I finally got smart and had my local machine shop cut me some junk valves to use for protecting the seats. I think they came from a Toyota or something but anyhow I had them cut so that they fit almost perfectly flush with the chamber roof. Wish I had done this earlier - makes the job so much easier. Here are some pics of the chamber work coming along. __________________ Robert ZR-1 Net Registry Oregon State Director 91 ZR-1 #431 Black/Black LPE 368

04-02-2011	#84
Polo-1 Join Date: Sep 2005 Location: Washington Posts: 955	Re: Some "Dynomite" Heads! you might be on to something Rob " under sized valves "

04-07-2011	#85
Locobob Join Date: Jan 2004 Location: Portland, OR Posts: 1,057	Re: Some "Dynomite" Heads! Almost done, just some fine tuning to do. __________________ Robert ZR-1 Net Registry Oregon State Director 91 ZR-1 #431 Black/Black LPE 368

04-07-2011	#86
Polo-1 Join Date: Sep 2005 Location: Washington Posts: 955	Re: Some "Dynomite" Heads! a little more polish and they will be ready to hang on the wall They look really nice Rob.

04-07-2011	#87
tomtom72 Join Date: Dec 2004 Location: Jacksonville, FL USA Posts: 4,645	Re: Some "Dynomite" Heads! I have to stop looking at your work Bob or I will start to hate my stock ZR-1.....which I used to be extremely happy with I might add! Man that is just some fine head work! I have head envy! __________________ 1990 ZR-1, Black/grey, #2233, stock. ZR-1 Net Reg Founding Member #316 & NCM member Last edited by tomtom72; 04-07-2011 at 07:42 PM.

04-07-2011	#88
FU Join Date: Mar 2004 Location: Found Member Posts: 4,346	Re: Some "Dynomite" Heads! Stock is boring Tom. Take a ride to Chicago __________________ Frank Urbo. NCM Lifetime member # 982 Registry Founding # 237

04-09-2011	#90
Locobob Join Date: Jan 2004 Location: Portland, OR Posts: 1,057	Re: Some "Dynomite" Heads! CC ing again. I did this before starting just to establish a baseline but now the focus is on chamber to chamber consistency. Anyhow the my results after working the chambers came in at a smallest of 41.5cc and a largest of 42.5cc. I do each chamber twice as an error check, if I see any substantial difference then I do it over until I get a consistent result. My method has proven to be accurate and repeatable, I figure my margin of error is probably under .5cc. The largest volume was the chamber I used to make my template - which I expected as it shows the difference between the template and the marker trace on the others. The next step is to remove some more material to bring all the chambers up to the volume of the largest. Here we have a chamber filled with water and a bit of food coloring. The plate over the top is 1/2in plexi with some Vaseline around the edges and valves for sealant. How much difference is 1cc? About 2.4% Here is 1cc poured into the corner of a chamber - probably looks like more than it is since the head is tilted. Anyhow when I'm done they will all be at 42.5cc and then the heads will be surfaced to achieve the desired compression ratio. __________________ Robert ZR-1 Net Registry Oregon State Director 91 ZR-1 #431 Black/Black LPE 368