[twinturrbo406]

Originally Posted by dci

Pont428, I don't know if we have ever met before. Were are you located?



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 !!!!!

... that's Lynn's brother Steve ... i met him at PRI, he's a very nice guy ...

[tom s]

Steve or Stacy?Tom

[twinturrbo406]

Originally Posted by tom s

Steve or Stacy?Tom

... i thought it was Steve, but you might be right with Stacy ...

[J.C.you]

Originally Posted by BruceWilkie

I'm guesstimating that intake pushrod is off center approx 1.25" .... To straighten that out means move the intake lifter bore centers the same amount... offsetting the lifter cup plays havoc on the roller and Crower told me beyond .150" is not a good idea...they dont like any offset whenever possible. The exhaust is also offset in that pic just not highlighted it isnt as severe. So your definately talking major block changes and a new cam core to run the big port at very high rpm reliably.

Bruce, the port is close to 4.6 csa now with no mods to the lifter bore other than the liners. For a small cube motor such as the 445 I mentioned to achieve the target rpm of 10k before choke we would only need a port with approx. 4 csa. Definitely a smaller/narrower port and less, if any angle needed after moving the lifter bores and camshaft lobes. I believe there is enough meat in the existing IA block to get there.

[BruceWilkie]

Originally Posted by Pont428

He definitely will eat that one JC. They will do push rod in first to see what power it makes. Air is Air, it doesnt know what RPM the engine is. Why dont we just wait and see? I remember when everyone said a 4.5 bore wasnt possible, and here you are JC! Lynn is doing close to 4.6 bore for me.

And fuel is fuel, it doesnt know what the rpm of the engine is either...

Besides dealing with the inertia differences of those two, there are other factors that affect both in how they behave and arrive in the cylinder in a good homogenous mix ready to burn. Its not just csa and adequate airflow thru the lift curve.

I think Tony was smart to move the pushrod out of JC's port... Not that he couldnt have made more space around the pushrod (or a port divider) for same csa...
One just cant divide the port part of the way or all the way from intake plenum to the valve seat without consideration of ALL factors that need to occur or could occur. Then not forget the factors that occur between the throttle and the valve, across the valves during overlap and things that are occuring before and after valves open and close on both sides of the head.

JMO but for JC's build requirements I think Tony chose a way to meet the build requirement and avoid alot of additional and costly R+D. Job well done!

This proposed 406 with 2.7 to 3.0 hp per ci mentioned earlier... if it is tried with the pushrod through the port there will be air/fuel issues to address differently than a "conventional" open port. (maybe direct cylinder injection helps???)
If the pushrod is run outside the port its going to take block changes among other things to build a valvetrain that can hold up to the rpm you are going to turn a 406 to the amount of rpm required to move all the air it would take for 2.7-3.0 hp per ci.

Seriously, good luck with this. Thats a heck of a goal!

Please understand Im NOT anti RAV... I think its a very cool choice for street, street-strip, serious brackets, even high level type builds to a point... but I think there is very good reason why its not in use in Pro-stock.

Lots of great talent amongst us... it would be awesome if "we" (as an affiliated group of Pontiac diehards) showed the other brand guys the way...

[BruceWilkie]

Originally Posted by J.C.you

Bruce, the port is close to 4.6 csa now with no mods to the lifter bore other than the liners. For a small cube motor such as the 445 I mentioned to achieve the target rpm of 10k before choke we would only need a port with approx. 4 csa. Definitely a smaller/narrower port and less, if any angle needed after moving the lifter bores and camshaft lobes. I believe there is enough meat in the existing IA block to get there.

IMO it would be best to only have one arc of travel to the pushrod vs the radial arc that occurs with a fore or aft offset...

This lifter movin and such would best be accomplished with a casting revision that allowed choices in lifter bore location and angles.
Orderable un-drilled, custom drilled or standard drilled.

Custom cam cores are pricey enough let alone if you end up with a lifter position that would require welding new boss locations. A revision to the casting is a one time change and it would still be usable for standard lifter locations.

[pastry_chef]

Originally Posted by dci

Scott, I could not find any info on anyone other than Steinbreck using a tunnel port head for Prostock. I did find some info on a 351 Ford with what they called a split port tunnel port design head. Kind of like what I have done with my heads. The guy claims it made 1023 HP. I could not find much more about it, except he claims it was outlawed because it gave the Ford boys an unfair advantage in Nascar. The heads were actually a Ford part in their motorsports catalog as recently as 1996. I know Tom V made mention of them, but other than that I could not find anything else about them. Does anyone know who the guy was that worked on this program for Junior Johnson? If so, I would love to get the guys number or email.

Don,

http://speedtalk.com/forum/viewtopic...&sid=0a1051f0c

See posts:

Darin Morgan » Sun Jul 02, 2006 6:41 pm

"The only tunnel port head I had anything to do with was that piece of crap Ford came out with because Junior Johnson though it would be a good idea. All I did was port it and flow it and tell them it would never work because the wet flow was total junk."

-------

This one is pretty interesting as well!

Darin Morgan » Mon Jul 03, 2006 3:39 pm

"I dont mean to be overly critical but this guy is living in Disney land if he thinks that thing will come close to 2.25hp/cid much less 2.6 or 2.7. Thats just plane silly! "

------LMAO

Then Lynn replies:
CMI Motorsports » Tue Jul 04, 2006

"I agree that Pontiacs do not have the capability now or in the near future of making 2.5 or greater HP per cubic inch. Sorry if one of my posts suggested that, but it was probably one post taken out of context with many other posts and threads. "

--------------------------

http://forums.maxperformanceinc.com/....php?p=4687111

More delirium! July 2012

Originally Posted by NHRASuperStock455SD

With our existing ports 2.7 for this engine is very capable, we must work very hard to get 2.9. We will post this project as it happens.

------------------

Where I am from, when we say we will do something, we DO IT!
Stop the BS.

[dci]

It's not my style to bash someones idea's and or products especially out in public. So I really have no comment on how or what Lynn's heads are capable of .

I can tell you that my 5 heads do flow very well as cast and respond well to porting. They sound really good on the flow bench and do not back up with a fairly conservative valve size. As for wet flow !! I really don't know what they will do yet. So I cannot spout off or beat on my chest until I have solid evidence of what I did with my port design will work. I have done some computer generated models of the flow path with my port design and that is how I came up with the design I did, but until the rubber hits the road. I am purely speculating. I have built several factory Ram Air 5 engines in my career, and I can tell you that they all liked rpm's even on bigger cube engines. So I knew that I had to increase port speed without sacrificing cfm to improve the factory heads. I have never wet flowed a set of ram air 5 heads (mine or factory), but if the wet flow is bad. You cannot tell by reading the spark plugs. All of the RA 5 engines I have built. When you pull the spark plugs they all look really good even after idling for extended periods. In my experience over my 30 + years of doing this. I have found that if you have fuel dropping out of the air from to much carburetor,poorly ported or designed heads, the wrong intake or anything that allows fuel separation. The spark plugs look like black wet pieces of @#$%, and all of the tuning in the world cannot fix it. So do I think there will be some wet flow issues to deal with? Maybe, but know one will know that until air and fuel pass through the engine. I do know though that you don't need a pushrod tube running through a port to have wet flow issues. I know that for a fact!!!!

I really did not start this thread to start a negative path, but a positive one to inspire and promote advancement with a traditional Pontiac engine. I some times wish I was like the rest of the herd out there, and liked Chevy's or Ford's. Fortunately or unfortunately, I guess it depends on how one looks at it. I have Pontiac blue blood and I cannot help but try to try and improve them. So if you guy's don't mind. Let's get back to the subject matter here.



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 !!!!!

[mike leech]

Very Nice post Don. Professional and classy....Just right

[dci]

I forgot to mention the one experience I had with a wet flow designed cylinder head. I had a customer bring me a 383 SBC that he put the latest and greatest wet flow designed cylinder heads on it. His car consistently ran 10.40's @126 mph with a set of chevy bowtie heads that I ported for him. He done some reading on this new wet flow designed head that was supposed to be better than their competitors heads by 20+ HP (I don't remember the exact HP). So he purchased these heads which had about the same port cc's as what he had on the engine, but a little bigger intake valve. Installed the new heads with no other changes reset the timing back to were it was on the engine originally and ran the car. First thing he said he noticed was the throttle response was a little slower and the drive-ability in the pits was poor. Does his burn out and stages the car and will not come up on the converter like it should. Makes a pass get's his time slip 11.08 @ 120 mph. So he thinks it needs re-jetted for the new heads, makes sense. Pulls a couple of plugs and looks really fat. Jets it down 3 in front and 2 in back. Makes another pass still not happy with the way it feels 11.20's @ 118 mph. Pulls the plugs they are looking better so he thinks well maybe the timing needs retarded a little even though the way the engine was with the old heads it only wanted 28 degree's total. He retards the timing to 26 total makes another pass 11.30's 116 mph. By this time he is think okay I screwed up something loads the car up and gets it back home. Checks for a head gasket not sealing, valve lash, all the things he knew had messed with. Nothing!!! He spent most of the summer trying to get the car the run like it did. Needless to say it never did run the number. He brings me the engine and wants me to freshen it up and tells me the story. When I pulled the heads off the engine the piston tops and combustion chambers were so sooty and still wet that it looked like he was running kerosene or diesel fuel. I tear the heads down and don't see anything way out of whack, but I notice that the short turns have a pretty sharp 90 in them almost a point at the apex. I call the customer tell him that I want to rework the heads before I button the engine up. He gives me the go ahead and I get started. When I put the head on the bench to see were it is at I cannot believe how dirty the port sounds. It's cackling hissing, gurgling the test pressure is jumping about 3-4 inches. The head just does not sound happy at all. I went in and radius ed the short turn blended the bowl and changed a couple of angles on the seat and matched the ports all up and put the engine back together. Long story short I have a very happy and loyal customer now and he picked up another 2 tenths from his original combo and 3 mph (10.20's @ 129). So my one and only experience with wet flow design was not a good one. I'm not saying that it's bad. Just saying it did not work in this situation.



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 !!!!!

[J.C.you]

Originally Posted by BruceWilkie

IMO it would be best to only have one arc of travel to the pushrod vs the radial arc that occurs with a fore or aft offset...

This lifter movin and such would best be accomplished with a casting revision that allowed choices in lifter bore location and angles.
Orderable un-drilled, custom drilled or standard drilled.

Custom cam cores are pricey enough let alone if you end up with a lifter position that would require welding new boss locations. A revision to the casting is a one time change and it would still be usable for standard lifter locations.

Bruce, we better stay in front of the keyboard if we want to start a budget build 2.3 motor. That is as classy as I could squander.

[J.C.you]

[QUOTE=pastry_chef;5158727]Don,

http://speedtalk.com/forum/viewtopic...&sid=0a1051f0c

See posts:

Darin Morgan » Sun Jul 02, 2006 6:41 pm

"The only tunnel port head I had anything to do with was that piece of crap Ford came out with because Junior Johnson though it would be a good idea. All I did was port it and flow it and tell them it would never work because the wet flow was total junk."

-------

This one is pretty interesting as well!

Darin Morgan » Mon Jul 03, 2006 3:39 pm

"I dont mean to be overly critical but this guy is living in Disney land if he thinks that thing will come close to 2.25hp/cid much less 2.6.


Morgan may have to eat that estimate of 2.25. The man is not infallible, we are not quoting bible verses.

[BruceWilkie]

Originally Posted by J.C.you

Bruce, we better stay in front of the keyboard if we want to start a budget build 2.3 motor. That is as classy as I could squander.

One works with what is available to work with... just pointin out a that a block revision that eases lifter bore location changes, opens the door in a way that allows resources to be better utilzed elsewhere. If you know goin in you have greater latitude in lifter placement than you previously had you can focus more on taking advantage of that vs trying to come up with a work-around.

In the quest to meet or beat current pro stock levels it may take another generation head design... Maybe on someones scribble pad because current blocks make it extemely difficult... impractical budget wise often sends Pontiac folks to the other brand... Not just little guy bracket racers... Make it easier for the guy with the scribblings on a notepad and that might encourage him to continue on an untried but promising path.

We WONT hit 2.7 per or anything greater without thinking forward. Bore spacing, cam tunnel placement, cam tunnel bore capability, and lifter bore spacing can lock us out of opportunities if we dont make revisions to the foundation that eases changes elsewhere.

We already seem locked to bore spacing... maybe a bit more deck width could be useful??? Room for other improvements/options in the deck??? Perhaps the cam tunnel can be revised for greater options??? Perhaps options in the mains area??? I already discussed the merit of easing lifter bore spacing and angle changes. Perhaps its time for an IA3 or MR2??? I think a lot of changes could be made to allow greater options and still be able to stay with all traditional pieces if one wants or needs to.

[Stan Weiss]

Originally Posted by BruceWilkie

One works with what is available to work with... just pointin out a that a block revision that eases lifter bore location changes, opens the door in a way that allows resources to be better utilzed elsewhere. If you know goin in you have greater latitude in lifter placement than you previously had you can focus more on taking advantage of that vs trying to come up with a work-around.

In the quest to meet or beat current pro stock levels it may take another generation head design... Maybe on someones scribble pad because current blocks make it extemely difficult... impractical budget wise often sends Pontiac folks to the other brand... Not just little guy bracket racers... Make it easier for the guy with the scribblings on a notepad and that might encourage him to continue on an untried but promising path.

We WONT hit 2.7 per or anything greater without thinking forward. Bore spacing, cam tunnel placement, cam tunnel bore capability, and lifter bore spacing can lock us out of opportunities if we dont make revisions to the foundation that eases changes elsewhere.

We already seem locked to bore spacing... maybe a bit more deck width could be useful??? Room for other improvements/options in the deck??? Perhaps the cam tunnel can be revised for greater options??? Perhaps options in the mains area??? I already discussed the merit of easing lifter bore spacing and angle changes. Perhaps its time for an IA3 or MR2??? I think a lot of changes could be made to allow greater options and still be able to stay with all traditional pieces if one wants or needs to.

Bruce,
What has the Pontiac bore spacing got to do with producing 2.7 HP per ci? It has been done with smaller bore spacing, just look at Australian Pro Stock.

Stan

[dci]

I don't think bore spacing has as much to do with it now as much as everyone thought a few years back. I think that with the advancements in cylinder heads for SBC especially which have a 4.400 BS. That there are some combos making that or close to it now. I know the Ausie Prostock is 4.500 BS, but that is for packaging purposes for that class. Obviously they have shorter decks so they need a little bigger bore to get the cubic inch, rod to stroke ratio that will work.

Anyone here run or know anyone who is running in NHRA comp eliminator? I know those guy's are around 2.7 + per cube and run all kinds of different engine combos.


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 !!!!!

[J.C.you]

I believe most current bore to stroke ratios in prostock are oversquare to the tune around 1.3 to 1 bore vs: stroke. Using that figure with a Pontiac blocks limitations, if one stretched the bore to 4.5 like we did, that figure would be a 4.5 bore to 3.45 stroke. If one wanted to stay with the mindset of 4.4 max bore, it would be 4.4x3.375.

[BruceWilkie]

Originally Posted by Stan Weiss

Bruce,
What has the Pontiac bore spacing got to do with producing 2.7 HP per ci? It has been done with smaller bore spacing, just look at Australian Pro Stock.

Stan

Ask any of them if they would like to give up bore space for stroke at whatever ci limit they run...

Bore space dictates bore size, which dictates valve size, which = potential flow capability, which = HP potential.

[pastry_chef]

Originally Posted by J.C.you

Darin Morgan » Mon Jul 03, 2006 3:39 pm

"I dont mean to be overly critical but this guy is living in Disney land if he thinks that thing will come close to 2.25hp/cid much less 2.6.


Morgan may have to eat that estimate of 2.25. The man is not infallible, we are not quoting bible verses.

Well.. between Darin's 2.25 and McCarty's repeated ongoing claims of 2.7 plus I know where I would place my bets..

And your comment now coming from someone who insisted the pushrod be removed from the port..
There's faith for ya.. LMAO

[J.C.you]

Originally Posted by pastry_chef

Well.. between Darin's 2.25 and McCarty's repeated ongoing claims of 2.7 plus I know where I would place my bets..

And your comment now coming from someone who insisted the pushrod be removed from the port..
There's faith for ya.. LMAO

Morgan didn't like the port because of the pushrod in the middle. I bet he would reconsider the 2.25 figure with it out of the port. Also we don't know what the old tunnel port casting they were working with looked like either. It may have been a pos. Lynns and Dons heads especially have potential to up the bar further than any inline head out there. Pro stock level? No, but I am talking 2.3 per cube not the 2.7 it seemed to have grown to.

[BruceWilkie]

Originally Posted by J.C.you

I believe most current bore to stroke ratios in prostock are oversquare to the tune around 1.3 to 1 bore vs: stroke. Using that figure with a Pontiac blocks limitations, if one stretched the bore to 4.5 like we did, that figure would be a 4.5 bore to 3.45 stroke. If one wanted to stay with the mindset of 4.4 max bore, it would be 4.4x3.375.

Put those dimensions in a 301 deck height block so you can run shorter lighter rods and a lighter crank and add smaller bearings while your at it.... 301 deck is 9.143 iirc... thats still a decent size for those who want more stroke... being a factory dimension helps in the fight to get allowed to run against the LS and SB2 and Ford small block stuff... especially if you make the argument that they all stretch their blocks to compete in 400 -460 ci range... We've lived there for years but didnt have the heads we have today... which in the right hands I see no reason why we cant meet or beat their power in that ci range. We have bore advantage over those motors and need to capitalize on it. They dont blink an eye to exploit any advantage they find... we need to do likewise.

When we run 500+ ci we are up against bigger bore motors... if running same ci that gives them an edge we cant match without lengthening our block. That bore space and valve size relationship matters... and it matters more than any piston speed advantage our longer stroke might have to offer.