PONTIAC ZONE TECH FORUMS
 

Go Back   PONTIAC ZONE TECH FORUMS >
Engine Tech
> Aftermarket News & Products
User Name
Password

sponser links

Reply
 
Thread Tools
Old 12-16-10, 08:56PM   #1
Gach
Administrator
 
Gach's Avatar
 
Join Date: May 2003
Location: ....
Posts: 18,426
Default DCI TIGER Head Facts

I thought this post by DCI...(which was posted on another Pontiac site) was pretty interesting. Info that I never knew...kind of changes things a
little bit as to what was actually developed and who laid claims to what.

I keep getting phone calls about the spec's for the original DCI TIGER Heads that I engineered and designed. So to help clear things up and eliminate hear say from twisted third party views. I have compiled a list of FACTS about my original DCI TIGER Heads.

Fact #1
The very first original prototype DCI TIGER head (that I still have), flowed 422 cfm .900 lift @28 inches of test pressure on a Superflow 600 bench. This is documented in High Performance Pontiac magazine October 2003 by Tom Demauro the editor.

Fact #2
The very first set of as cast or production DCI TIGER heads (on my engine now) that I produced flow 439cfm .900 @28 inches on a Superflow 600 bench. The only difference between these and the prototype head is the valve job. No port changes what so ever.

Fact #3
The original DCI TIGER heads valve sizes are 2.25 intake and 1.800 exhaust

Fact #4
The valve seats on the original DCI TIGER heads interlock. This was done to move the intake valve away from the cylinder wall as much as possible and unshroud it. This gave us .230 clearance on a 4.350 bore with a 2.250 intake valve.


Fact #5
The original DCI TIGER heads could be used on a factory block with a 4.190 bore and 2.25 intake valve, Although not recommended because of shrouding. About .080 clearance from cylinder with a 2.250 valve.

Fact #6
The DCI TIGER heads original combustion chamber as cast is a very good heart shape design with double quench areas, and works very well as cast. Although it was intended to be cnc machined for various combustion chamber sizes and shapes, depending on the application.

Fact #7
The original DCI TIGER heads were also engineered to use stud mounted rockers although not recommended. This was done for the Pro Street crowd using a .700 lift or less cam.

Fact #8
The original DCI TIGER heads water core is one of the heads best kept secrets. I engineered a large area of water into the center of the head to help alleviate the hot spot between the two center cylinders. I engineered this so that you could blow cool water into the center of the head and pull it out of the ends cooling the center of the heads first.

Fact #9
The original DCI TIGER Heads were engineered with multiple exhaust port configurations. A standard D-port, standard round port, raised 1 1/2" round port, and a version with the dog leg milled away for a straight shot exhaust.

Fact #10
My original DCI TIGER heads also had a distinguishing ribbed exhaust surface strictly for cosmetics only. This way when someone seen the heads on your engine, they knew you were packin!!

Fact #11
This last fact is in my opinion the most important. I had tried several different foundries to get my head to market to no avail. Because the head is a low volume part, the foundries continued to push me to the back delaying my production of the heads. I knew that I had a very good product and wanted to see it brought to market. So after some very deep and serious thought, I decided to pass the torch and let someone else continue what I started. TO GET MY TIGERS to market!!! Believe me that was not easy. Kind of like giving up your first born. Looking back now, I wish I would have just taken a break from the project and put together another plan of attack. So many of you guy's out there tried to get me to keep the head and regroup, but I wanted to see the TIGERS on cars at the track. I knew the TIGERS would take our beloved traditional Pontiac's to the next level and was willing to give them up for that. I have since learned allot, and with my new DCI Ram Air V heads have no intention of ever selling my design to anyone. I WILL!! get these to market with some patience. I would like to say, Thank You to all of you that have supported me and my ideas. Stay tuned as I get my new heads to market soon and raise the bar again.

Don Johnston
DCI MOTORSPORTS INC.
330-628-3354 cell
330-850-5050 shop
Designer of the TIGER Heads and the new DCI Ram Air V heads coming soon!!
Attached Thumbnails
Click image for larger version

Name:	DCI%20541%20TIGER%20001.jpg
Views:	363
Size:	69.3 KB
ID:	22973   Click image for larger version

Name:	DCI%20541%20TIGER%20005.jpg
Views:	348
Size:	52.1 KB
ID:	22974  
__________________
The things they hide, the way they spin things, the excuses that they make and the things they omit.
Gach is offline   Reply With Quote
Old 12-16-10, 09:03PM   #2
Gach
Administrator
 
Gach's Avatar
 
Join Date: May 2003
Location: ....
Posts: 18,426
Default

Hum one of the most interesting facts...at least for me was

Quote:
Fact #8
The original DCI TIGER heads water core is one of the heads best kept secrets. I engineered a large area of water into the center of the head to help alleviate the hot spot between the two center cylinders. I engineered this so that you could blow cool water into the center of the head and pull it out of the ends cooling the center of the heads first.
__________________
The things they hide, the way they spin things, the excuses that they make and the things they omit.
Gach is offline   Reply With Quote
Old 12-17-10, 01:15AM   #3
Stan Weiss
Registered User
 
Join Date: Oct 2010
Location: Philadelphia PA
Posts: 782
Default

I believe these are the numbers from that article along with a calculation.

Stan


Code:

Bore = 4.2000     Stroke = 4.5000          Rod Length = 6.8000     RPM = 6000
Wrist Pin Offset = 0.0                     Number of - Intake Valves = 1 - Exhaust Valves = 1
Intake Valve Size = 2.25                   Exhaust Valve Size = 1.8
Intake Valve / Bore Ratio = 0.535714       Exhaust Valve / Bore Ratio = 0.428571
Intake Valve Area = 3.976078 sq. in.       Exhaust Valve Area = 2.54469 sq. in.
Intake Valve Stem Size = 0.3415            Exhaust Valve Stem Size = 0.3415
Intake Valve Stem Area = 0.091595 sq. in.  Exhaust Valve Stem Area = 0.091595 sq. in.
Valve Lift at which the Valve Area and Window / Curtain Area are the SAME SIZE
At that point the velocity will be the same in both areas
Intake Valve Lift = 0.5625 Inches          Exhaust Valve Lift = 0.45 Inches
Intake Centerline = 111.0                  User Selected DC - Discharge Coefficient = 0.5
Bowl CSA (0.92) Intake = 3.2738 sq. in.    Bowl CSA (0.91) Exhaust = 2.0157 sq. in.
Valve Lift at which the Bowl Area and Window / Curtain Area are the SAME SIZE
At that point the velocity will be the same in both areas
Intake Valve Lift = 0.46314 Inches         Exhaust Valve Lift = 0.356447 Inches


    Intake                Curtain                Bowl             Valve        CFM per Sq. In.   L/D
 Lift     CFM     fps       DC     Area      fps       DC      fps       DC      Bowl    Valve  Ratio
 .100   76.000  258.043   0.7366    .707   55.716   0.1591   45.874   0.1310   23.215   19.114  .044
 .200  145.000  246.160   0.7027   1.414  106.300   0.3035   87.523   0.2499   44.292   36.468  .089
 .300  208.000  235.408   0.6720   2.121  152.485   0.4353  125.551   0.3584   63.536   52.313  .133
 .400  267.000  226.637   0.6470   2.827  195.738   0.5588  161.164   0.4601   81.558   67.152  .178
 .500  316.000  214.583   0.6126   3.534  231.660   0.6613  190.741   0.5445   96.525   79.475  .222
 .600  358.000  202.587   0.5783   4.241  262.451   0.7492  216.092   0.6169  109.354   90.038  .267
 .700  388.000  188.197   0.5372   4.948  284.444   0.8120  234.201   0.6686  118.518   97.584  .311
 .800  412.000  174.858   0.4992   5.655  302.038   0.8622  248.687   0.7099  125.849  103.620  .356
 .900  422.000  159.202   0.4545   6.362  309.369   0.8832  254.723   0.7272  128.904  106.135  .400


   Exhaust                Curtain                Bowl             Valve        CFM per Sq. In.   L/D
 Lift     CFM     fps       DC     Area      fps       DC      fps       DC      Bowl    Valve  Ratio
 .100   63.000  267.380   0.7633    .565   75.013   0.2141   59.418   0.1696   31.255   24.757  .056
 .200  112.000  237.671   0.6785   1.131  133.356   0.3807  105.632   0.3015   55.565   44.013  .111
 .300  161.000  227.768   0.6502   1.696  191.699   0.5472  151.846   0.4335   79.874   63.269  .167
 .400  196.000  207.962   0.5937   2.262  233.372   0.6662  184.856   0.5277   97.238   77.023  .222
 .500  230.000  195.230   0.5573   2.827  273.855   0.7818  216.922   0.6193  114.106   90.384  .278
 .600  252.000  178.254   0.5089   3.393  300.050   0.8566  237.671   0.6785  125.021   99.030  .333
 .700  264.000  160.064   0.4569   3.958  314.338   0.8973  248.989   0.7108  130.974  103.745  .389
 .800  269.000  142.709   0.4074   4.524  320.292   0.9143  253.705   0.7243  133.455  105.710  .444
 .900  276.000  130.153   0.3716   5.089  328.626   0.9381  260.307   0.7431  136.928  108.461  .500



              Please Press any key to exit this window.

CARFOR - Registered to:   Stan Weiss

Version: 3.10.0 -- December 08, 2010
Copyright (c) 1987-2010
Stan Weiss / World Wide Enterprises
Website: http://users.erols.com/srweiss/index.html
E-mail: srweiss@erols.com
Stan Weiss is offline   Reply With Quote
Old 12-17-10, 06:45AM   #4
GET IT ON
Pontiholic
 
Join Date: Dec 2006
Location: Pacific, Missouri
Posts: 1,112
Default

I remember when Don was first developing the Tigers. Since he gave them up so to speak to get them to market, the newer versions have had much changed and not all the changes were to the better!!! Cooling is 1 major issue. It would have been nice to have seen Don's original design on Kaase's EMC engines as I think Kaase would have won both times with the Pontiac engines instead of over heating.
GET IT ON is offline   Reply With Quote
Old 12-18-10, 06:31PM   #5
Big Speed
Registered User
 
Big Speed's Avatar
 
Join Date: Apr 2008
Location: Paterson New Jersey
Posts: 124
Default

To whom it may concern,the Tiger water jacket tooling is still original as designed,however other components of the original tooling have been repaired,replaced or modified.As to cooling problems their are none.The architecture of the traditional Pontiac engine,10 headbolts and exhaust valves paired next to each is not the most desirable.With Tiger heads in the lead of naturaly asspirated horsepower and on track performance,the paired exhaust valves present a challenge for engine builders.when you fill the cylinder better, the cylinder pressure trys to push the heads off the top of the engine,The Allpontiac Grand am has the original head gaskets from the dyno session in May 2009, DCI developed a very good port,it took the Allpontiac Team to get it to market.Bill C.
__________________
Checkered Flag Machine & Ceralli Competition Engines
Competition engines , Induction development & 5-axis CNC porting
http://www.checkeredflagmachine.net/
Big Speed is offline   Reply With Quote
Old 12-18-10, 10:37PM   #6
Gach
Administrator
 
Gach's Avatar
 
Join Date: May 2003
Location: ....
Posts: 18,426
Default

Allpontiac put allot more R&D into the Tiger heads.
__________________
The things they hide, the way they spin things, the excuses that they make and the things they omit.
Gach is offline   Reply With Quote
Old 12-19-10, 01:33AM   #7
Gach
Administrator
 
Gach's Avatar
 
Join Date: May 2003
Location: ....
Posts: 18,426
Default

Sounds like the Tiger heads is king for making the most HP.
__________________
The things they hide, the way they spin things, the excuses that they make and the things they omit.
Gach is offline   Reply With Quote
Old 12-19-10, 12:36PM   #8
Mb125
Registered User
 
Mb125's Avatar
 
Join Date: Mar 2005
Location: AZ
Posts: 4,038
Default

Heads alone don't make the HP
__________________
You can shear a sheep many times, but you can only skin them once.
Mb125 is offline   Reply With Quote
Old 12-19-10, 02:21PM   #9
GREATGTO
Pontiac Nut
 
GREATGTO's Avatar
 
Join Date: Dec 2004
Location: DEBARY FLORIDA
Posts: 410
Default

Quote:
Originally Posted by Mb125 View Post
Heads alone don't make the HP
Thats the truth! How far is one willing to go with machine work and oiling systems to extract the most power from an engine, not to mention induction design.Plus you have so many choices to make with engine internals, some will make more hp than others for different applications. Then you still have the intended purpose of the car, obviously a car that sees a lot of street driving will not incorporate all the tricks to make the hp.

The dirty little secret is the fact most will not disclose what it takes for them to make the most HP, everyone would like you to believe its because of the cylinder heads..

You want to do a little experiment?

Build an engine with a maximum cost/budget of $8,000 dollars, use any heads you want but the cost of those heads are part of the 8k budget, this will give you a better idea of which heads do what when you remove all the all out race engine building techniques, some racing heads aren't even usable with small budgets. It takes a lot more to make them usable.


It takes a certain level of spending to make things work,very few heads can work well on both sides of the spectrum!

Last edited by GREATGTO : 12-19-10 at 02:55PM.
GREATGTO is offline   Reply With Quote
Old 12-19-10, 03:35PM   #10
Gach
Administrator
 
Gach's Avatar
 
Join Date: May 2003
Location: ....
Posts: 18,426
Default

Allot of it boils down to what you can afford...I don't think anyone cares about making 1000-1100 hp if you can't afford it. Impressed with those who do...sure, but doesn't mean anything to you.
__________________
The things they hide, the way they spin things, the excuses that they make and the things they omit.
Gach is offline   Reply With Quote
Old 12-19-10, 09:22PM   #11
Gach
Administrator
 
Gach's Avatar
 
Join Date: May 2003
Location: ....
Posts: 18,426
Default

You have to wonder why "Butler's Twin Turbo Car "...is runing Wide Ports Being he's a Tiger Head dealer. So I guess that's open for debate. Seeing he has the fastest ever recorded ET. Things that make you go Humm?.
__________________
The things they hide, the way they spin things, the excuses that they make and the things they omit.
Gach is offline   Reply With Quote
Old 12-19-10, 10:08PM   #12
GREATGTO
Pontiac Nut
 
GREATGTO's Avatar
 
Join Date: Dec 2004
Location: DEBARY FLORIDA
Posts: 410
Default

Quote:
Originally Posted by EC View Post
I would bet that Butler would say he can make more power with the Tiger heads but at 2800hp and more power than his car can handle now, why would he? If the e-head made more power then I am sure Rex and Langer would be running them, don't you think so?
That all depends on what support AP gives langer and rex, if they pay the same price as everyone else for blocks and heads you might have a point.. Not saying they don't! Im just asking the question?
GREATGTO is offline   Reply With Quote
Old 12-19-10, 10:31PM   #13
GREATGTO
Pontiac Nut
 
GREATGTO's Avatar
 
Join Date: Dec 2004
Location: DEBARY FLORIDA
Posts: 410
Default

Quote:
Originally Posted by EC View Post
I have no idea if they do or don't but do you really think that the e-head can make more power than the Tiger heads? The Tiger is king. Until someone can like up next to Rex or Langer weighing roughly the same and beat them it will stay that way. IMO
You dont know much about langers engine do you? He uses just about every trick he can come up with to free up hp, its not just the heads. .Im sure he has a lightened crank rods and pistons as well, wonder how often he has to change valve springs? Better valve control frees up hp but who can run those springs over long duration of time or on a street engine? Bottom line its a race car, it should be the fastest. Most guys I know are building double duty cars, street/strip. The day will come when someone knocks him off the #1 spot NA same weight, I just dont know of anyone wanting to build an engine like he has, most want to drive their cars more.

I have a 2,800 crank in my engine, to have it lightened would be another 6 to 8 hundred dollars on top of the 2,800. I didnt do it because Im not looking to get every last hp from my engine, thats just one example.

Last edited by GREATGTO : 12-19-10 at 10:42PM.
GREATGTO is offline   Reply With Quote
Old 12-19-10, 11:28PM   #14
GREATGTO
Pontiac Nut
 
GREATGTO's Avatar
 
Join Date: Dec 2004
Location: DEBARY FLORIDA
Posts: 410
Default

Quote:
Originally Posted by EC View Post
I didn't know that light weight cranks, rods and pistons added hp. Good to know. You paid a lot for your crank. I would have thought for that kind of money it would be lightened. Good luck on your quest for 8s on pump gas. I am sure you will get there with no problem with all the expensive parts you have.
Less mass and less drag will let the engine RPM quicker.Its one of the reasons sbc have been kicking pontiacs butts for many years. The lighter you can make a pontiac engine the better off you will be. I did weigh my rods and pistons , with the BME 426 rods and the custom pistons I have Im just slightly heavier than a sbc steel roded with lightweight piston, so Im on the right track. Any drag or resistance you can remove from an engine will always increase hp, same reason titanium valves are used, to remove weight and resistance and to prolong spring life, better sealing valves = more hp, even running thinner weight oil will usually increase hp.. You can also look at oiling systems, drysumps make more power too, why? Less drag and windage . The point being hp is found in many places, not just the heads.

Last edited by GREATGTO : 12-19-10 at 11:43PM.
GREATGTO is offline   Reply With Quote
Old 12-19-10, 11:56PM   #15
GREATGTO
Pontiac Nut
 
GREATGTO's Avatar
 
Join Date: Dec 2004
Location: DEBARY FLORIDA
Posts: 410
Default

Quote:
Originally Posted by EC View Post
I agree that lighter components will allow the engine to rev quicker but will those light components show a hp gain on the dyno?
I dont know how long you have been into pontiacs but just look back when aluminum rods started becoming popular with pontiac racers, all of a sudden their cars were faster and they blew up less, reason being they made more hp and had mass removed where it was much needed. When building a pontiac engine I never use steel rods, for a daily driver sure go ahead and use steel rods, but for racing/street strip I wont. Like I said, less drag/resistance will increase hp, always has for every dyno run Iv ever seen. The only time I ever heard of weight reduction in an engine being a negative was in a boosted 4 cyl engine, they got too light and it lost ET, went back to slighly more weight and it gained the ET back.
GREATGTO is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
New Tiger Head Flow Numbers Robert C. Tiger Head 14 12-10-08 09:42PM
Street Tiger Head 806 HP. AWESOME! Gach Engine Tech Discussion - Street or Strip 14 05-20-06 12:34PM
DCI Tiger Heads, good news Gach Aftermarket News & Products 7 07-02-05 02:54PM


All times are GMT -3. The time now is 04:48AM.

Featured Ads
Ken's Speed & Machine
Mayhem Turbocharging

Carter Cryogenics.  What can we freeze for you?

Pacific Performance Racing

Central Virginia Machine Service.  Home of the Injun Engine!

All Pontiac Engine Kits

Larry's Auto Machine.  Full serivce auto, marine machine shop, domestic and foreign.

Powered by vBulletin® Version 3.6.8
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
2001 - 2007 PontiacZone.com
Page generated in 0.13589 seconds with 44 queries