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GTOGEORGE · 06-30-2013, 10:58 AM

Don,
I'm saving my money now! I'm planning on retiring from US Steel in couple of years (I'm thinking 43 years in a steel company is enough) money could be tight then so I better get them now!

Don't know who's heads I'll end up with yet............if you are at Norwalk we can talk (got lots of questions).

Thanks,
George

dci · 07-08-2013, 04:04 PM

GREAT news!!!! I just got off the phone with the machine shop and the first set of heads is ready for pick up. I cannot get there until tomorrow afternoon, but as soon as I get back with them I will post pic's. I will not be able to sleep tonight.

Don Johnston
DCI MOTORSPORTS INC.
330-850-5050 shop
330-628-3354 cell
Designer of the DCI Tiger Heads and the new DCI Ram Air 5 Heads !!!!!

RAIV-Z · 07-08-2013, 04:55 PM

Excellent news Don, I can't wait to see them!

moparcolt · 07-08-2013, 05:27 PM

I can't wait to bolt them on my motor!

dci · 07-10-2013, 11:59 AM

Well here they are!!! I have been waiting for this moment for a long time like so many of you. I have to say I am very pleased with quality of castings and machine work. Everything is spot on and looks great. Quick initial inspection looks really good for just coming out of the gate. I do have some things that I do not like and they will be addressed before taking orders. Nothing major though, it's things like the combustion chamber design which I can easily change. Another is the spark plug location again an easy change, but other than that. I am very happy with the final product. I am trying to find a combustion chamber design that will work for 72cc to 90cc range, and that is not an easy task. All in all though every thing is were it is supposed to be and very repeatable. Keep in mind that these were designed to be street friendly as well as a good platform for racing. So in one of the pic's you can see that they will fit on a 4.120 bore and the intake valve still has about .130 clearance. My next step is to put these on a cmm to verify bolt hole locations etc.etc. After that I will install the seats and guides and valve job them. I will be trying different seat configurations until I come up with one that gives me the best overall port flow and velocity. Not necessarily the best peak flow. Peak flow numbers are impressive to brag about, but do not always produce the best track performance. One area that will need attention before flow testing is the cast in pushrod wing. The reason for it being so big is that metal does not like to flow through tiny or tight area's. So I had to make these over size for production casting. Not a big deal, just takes a little time with a hand grinder to reduce their size.

We are getting close to taking orders. I really appreciate everyone that has waited and would like to get their hands on these ASAP, but I am not quite ready yet. As you can see we are very close and believe me. No one wants them to be for sale more than me!!!!

Don Johnston
DCI MOTORSPORTS INC.
330-850-5050 shop
330-628-3354 cell
Designer of the DCI Tiger Heads and the new DCI Ram Air 5 Heads !!!!!

dci · 07-10-2013, 12:08 PM

Here are a few more. In the pic with the head gasket. If you look close you will see that I moved some of the water holes out. I did this for the larger bore engines and will be getting head gaskets made to accommodate the changes. This is a weak spot and usually were I see head gaskets blow with allot of cylinder pressure. They will still line up with factory blocks as well.

Don Johnston
DCI MOTORSPORTS INC.
330-850-5050 shop
330-628-3354 cell
Designer of the DCI Tiger Heads and the new DCI Ram Air 5 Heads !!!!!

slowbird · 07-10-2013, 12:09 PM

Don what is the valve spacing? Wondering what size valves will fit. Also you said the valve would be .130 off the wall of a 4.120 bore what size intake valve gives that?

Sirrotica · 07-10-2013, 12:09 PM

Very nice Don, I guess you feel like a proud father about now

.

It's a great time to be a PONTIADDICT......................

ho428 · 07-10-2013, 12:12 PM

I think the heads look great, but why would you have the chamber with two points? Looks like that would hurt flame travel and swirl and create a dead spot as well as two hot spots on the points.

I guess I'm just used to seeing this.

dci · 07-10-2013, 12:24 PM

Thanks Brad.

slowbird,
Valve sizes I am currently set up for are 2.20 intake and 1.70 exhaust. Valve spacing right now is 2.020. That gives us .040 between valves and puts the exhaust .050 off the cylinder wall. If someone wants to they could reduce the exhaust valve size to 1.68 and run a 2.25 intake valve and still be ok. Obviously on bigger bores these coordinates will change because of the the real-estate that will be available.

Don Johnston
DCI MOTORSPORTS INC.
330-850-5050 shop
330-628-3354 cell
Designer of the DCI Tiger Heads and the new DCI Ram Air 5 Heads !!!!!

GTOGEORGE · 07-10-2013, 12:39 PM

Far Out!

GTO George

slowbird · 07-10-2013, 12:48 PM

Quote:

Originally Posted by dci

Thanks Brad.

slowbird,
Valve sizes I am currently set up for are 2.20 intake and 1.70 exhaust. Valve spacing right now is 2.020. That gives us .040 between valves and puts the exhaust .050 off the cylinder wall. If someone wants to they could reduce the exhaust valve size to 1.68 and run a 2.25 intake valve and still be ok. Obviously on bigger bores these coordinates will change because of the the real-estate that will be available.

Don Johnston
DCI MOTORSPORTS INC.
330-850-5050 shop
330-628-3354 cell
Designer of the DCI Tiger Heads and the new DCI Ram Air 5 Heads !!!!!

Will you be making a head with a different valve spacing for the larger bore engines?

LMSRACER · 07-10-2013, 02:09 PM

Quote:

Originally Posted by dci

Thanks Brad.

slowbird,
Valve sizes I am currently set up for are 2.20 intake and 1.70 exhaust. Valve spacing right now is 2.020. That gives us .040 between valves and puts the exhaust .050 off the cylinder wall. If someone wants to they could reduce the exhaust valve size to 1.68 and run a 2.25 intake valve and still be ok. Obviously on bigger bores these coordinates will change because of the the real-estate that will be available.

Don Johnston
DCI MOTORSPORTS INC.
330-850-5050 shop
330-628-3354 cell
Designer of the DCI Tiger Heads and the new DCI Ram Air 5 Heads !!!!!

Don,
From your information here's what I get.

I come up with a Valve Spacing of 1.990". That's with the Intake Valve Centerline @ 0.830" from the Bore Centerline and the Exhaust Valve Centerline @ 1.160" from the Bore Centerline.

That gives, with a 4.350" Bore and a 2.200" Intake Valve and a 1.700" Exhaust Valve, an Intake Valve to Bore Clearance of 0.245" and an Exhaust Valve to Bore Clearance of 0.165".

Is that correct ?

Thanks,
Larry S.

dci · 07-10-2013, 02:36 PM

ho428, The combustion chambers are just roughed in and a starting point. The peaks you are referring to will be rounded to reduce the sharp edges. Something that you need to remember and allot of guy's even engine builders forget or don't know. Is the combustion chamber is actually part of the over all port and has a big influence on the port. These peaks also contribute to swirl helping to prevent fuel fall out. Gasoline or any fuel for that matter cannot burn if it is not atomized with oxygen. Something else about combustion chambers, Is not one design fits all. Nobody not even GM,Ford, and Chrysler have any idea what an engine likes for combustion chambers.

slowbird, I will definitely be changing things around for larger bores. I made these so I can get a 2.450 intake valve in them on larger bores. I have even been kicking around a slightly canted intake valve. The street version's csa at the port opening after you take out the area the pushrod tube takes up is around 3.5". My race version I think we can get 5" after the tube area is subtracted.

Don Johnston
DCI MOTORSPORTS INC.
330-850-5050 shop
330-628-3354 cell
Designer of the DCI Tiger Heads and the new DCI Ram Air 5 Heads !!!!!

dci · 07-10-2013, 02:49 PM

LSM, You are real close with the scenario you created for our street version on a big bore. My race version I will try and maintain the same intake valve clearance with a 2.450 valve, but we will loose some of the exhaust valve clearance. Which is not a problem for the exhaust. You could literally have the exhaust valve rubbing on the cylinder wall and not hurt flow. The intake valve is way more sensitive though.

A 1/4" of intake valve to cylinder wall clearance is going to definitely promote air flow.

Don Johnston
DCI MOTORSPORTS INC.
330-850-5050 shop
330-628-3354 cell
Designer of the DCI Tiger Heads and the new DCI Ram Air 5 Heads !!!!!

Flyin79bird · 07-10-2013, 10:43 PM

Don, maybe my eyes are playing optical illusions with my head but I swear that the intake valve on these heads looks canted??? If so, I think you are headed in a good direction for sure.

RAIV-Z · 07-11-2013, 07:23 PM

Looks like you’ve got some quality RA-V heads there Don. How large of a push rod will you be able to fit on the intake side?

dci · 07-15-2013, 11:45 AM

Flyin79bird, The head the way I have it right now does not have a canted intake valve, but I am seriously contemplating it for the race version.

Ed, Currently the pushrod hole is .530". After we do some test fitting, I may open that up to .562". That way a 1/2" pushrod should fit with no problem, but for sure I do not see a problem with a 7/16" pushrod right now.

Don Johnston
DCI MOTORSPORTS INC.
330-850-5050 shop
330-628-3354 cell
Designer of the DCI Tiger Heads and the new DCI Ram Air 5 Heads !!!!!

cgeise · 07-15-2013, 12:12 PM

Just a thought - with the pushrod being in a hole like it is It would seem that ratio change with rocker arms is not going to work out well ??

Tom Vaught · 07-15-2013, 03:14 PM

Any change in the Rocker Arm ratio I believe would move the pushrod closer to the exhaust side of the head. Nothing says you could not make that cast area a slot vs a hole and have the ability to still seal that area and have from 1.5 to 1.9 Rocker arm ratios if designed properly. The wing area behind the pushrod drilling should have lots of material there.

Tom Vaught

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