#54493 - 12/30/09 06:34 PM
Re: Dyno day for a 250
[Re: samwise68]
|
tlowe #1716
12 PORT ADVERTISER
Active BB Member
Registered: 04/01/04
Posts: 2347
Loc: Dysart, Iowa
|
Jalopy,
I am working on getting a 3 weber side draft setup to test with. Hope that helps.
You are correct , not as many head/ cam swaps will need to be done. Still would probably test about 6 cams. It is good to see what works and at what ranges it works.
Sam,
The BSFC#'s are exactly what you need. They show how efficient the engine is operating, atleast for us @ wide open throttle.
The lower the #, the more more efficient the engine.
No date is picked yet, Going to get started with the lower end after the new year, glad the 292 was done before the Christmas rush! Tom
Tom
|
|
Top
|
|
|
|
|
#54545 - 01/02/10 08:20 AM
Re: Dyno day for a 250
[Re: jalopy45 #4899]
|
Mean buzzen half dozen A.K.A. Hank
Active BB Member
Registered: 09/23/04
Posts: 4585
Loc: Ca
|
The 3X2 ,2bbls should work pretty good.
The only problem I had when running 3 DCOEs of comming out of tune was just the carbs being out of sync,just a couple minutes w/a motorcycle carbs stick (mercury stick) hooked up & easy adjustment.
Even when they did come out of adjustment,it would be easy to feel the roughness & idle & when slowly excellerating,,,W.O.T. could not tell the difference if they were out of sync.
Changing jets ,emulsion tubes etc, have got to be the most simple things to do on DCOE's(Sidedraft Webers) ,no draining of the float bowls, reuse top gasket,etc,simple ,simple ,simple.
MBHD
_________________________
12 port SDS EFI 
|
|
Top
|
|
|
|
|
#54719 - 01/09/10 10:27 AM
Re: Dyno day for a 250
[Re: Mean buzzen half dozen A.K.A. Hank]
|
Mean buzzen half dozen A.K.A. Hank
Active BB Member
Registered: 09/23/04
Posts: 4585
Loc: Ca
|
Here is a thought for the next 250 dyno.
Tom can use some intake port dividers for the 250 dyno session.
I noticed his statement about how good his intake port dividers makes more power w/no dyno proof.
Track proof is not reliable as was pointed out earlier. Tire pressures being different, temps of the day, alititude,standard degree day & so-on.You had an off day.
I have no doubt that w/his deviders installed ,the idle improved,better throttle response,why,? increased air velocity through the intake port.
Would probably get simular,(not as much) results by using the offy intake manifold instead of the Clifford he is currently using.
By deviding the intake port & making the intake port window so small,you could possibly see an increase in your low end power,but in the upstairs dept of higher RPM,it will make less power,the head can't breath w/that type of devider.
When you install intake port deviders it will severely cut the flow CFM wise to the intake ports,not just by a little ,,by a lot.
Now w/Tom posting w/the 194 cyl head is down flow about 20 or so CFM as compared to the open chamber head,thus making less power, would'nt you think this can be or could be a posible contradiction?
How can you can more power if you loose CFM flow of you cylinder head? His dyno session of the 194 cyl head proved it made less power everywhere, the 194 head was down in flow.
Turbo 6 has already proved this idea is false w/dynoing.
He had used intake port deviders as to make sure all the cylinders were getting close to the same amounts of fuel.
With the intake port deviders,his power was down on the dyno,so he had to up the boost pressure to make equivelent HP w/no deviders.
W/the deviders installed, the intake port window has become too small to flow good. It is a restriction.BIG TIME!
That being said,,when you are forcing air/fuel into a poorly designed intake port such as our siamesed ports,, design is not as affected/critical as in a N/A engine.
Tom,
dont take this personal,,just thinking about what other items you could add to the dyno session.
And as far as every car nut wants to be different,well some people like recipe combos. Such as getting info from Toms dyno session.
Proven parts for a no hassle install.
Some guys just would like to go to a store & purchase recipe/combo & not have to think about it.
So car nuts are all different,that's all.
MBHD
_________________________
12 port SDS EFI
|
|
Top
|
|
|
|
|
#54721 - 01/09/10 11:27 AM
Re: Dyno day for a 250
[Re: Mean buzzen half dozen A.K.A. Hank]
|
CNC-Dude #5585
Active BB Member
Registered: 09/27/08
Posts: 1756
Loc: N. Georgia
|
We have discussed doing it. And it would be interesting to see if there is anything to it. But also remember Hank, that you are thinking of putting a port divider into a stock sized port. And your right, you will reduce the port window significantly, and might not even get much gain above a certain point. If you go to Glen Self's website, you will see how a Comp Eliminator size port looks, and that divding a port that is that large, such as my friend Darren did, wont be the same as dividing a stock size port. A race intake port is over 1-5/8" tall by 2-5/8" wide, so opening up the port opening to compensate for the divider will have to be done, or your correct, you will probably have no benefit from dividing it. The whole lump port vs. the divided port is going to require a completely different approach one to the other, and trying to adapt or use previous thinking from a lump port perspective, and applying it to the divided port concept might not show any advantage when done that way. I don't think it is going to be as easy as just putting a divider in the stock size port, and voila, you have a giant increase. You are going to have to open up the port to obviously regain some port area that was lost from putting the divder in place to start with, so that is where the R&D starts.
_________________________
There's no such thing as too much cam....only not enough engine!
12 Port Head Manufacturer
|
|
Top
|
|
|
|
|
#54722 - 01/09/10 11:52 AM
Re: Dyno day for a 250
[Re: Mean buzzen half dozen A.K.A. Hank]
|
tlowe #1716
12 PORT ADVERTISER
Active BB Member
Registered: 04/01/04
Posts: 2347
Loc: Dysart, Iowa
|
Hank,
I will probably test divided ports with the 250, am working on that now.
Remember with my turbo 292 and dividers. They helped me because of the Multiport EFI, it was a scavenging problem between opposing cylinders not a flow problem.
The head, being worked up has much widened intake to manifold port and the height is also increased. Now just need to make a nice divider. Tom
|
|
Top
|
|
|
|
|
#54725 - 01/09/10 01:04 PM
Re: Dyno day for a 250
[Re: CNC-Dude #5585]
|
GMCCORBETT
Active BB Member
Registered: 07/08/02
Posts: 34
Loc: Englewood, CO USA
|
If you go to Glen Self's website, you will see how a Comp Eliminator size port looks, and that divding a port that is that large, such as my friend Darren did, wont be the same as dividing a stock size port.
Scott -
I've been trying to get in touch with Darren Davis to talk about his work to the lump port head. The last number I had for him was at the header shop. Could you please give me an up-dated contact number?
Also, I did learn some interesting information from Sherman.
Thanks,
Bob
|
|
Top
|
|
|
|
|
#54770 - 01/10/10 12:06 PM
Re: Dyno day for a 250
[Re: CNC-Dude #5585]
|
tlowe #1716
12 PORT ADVERTISER
Active BB Member
Registered: 04/01/04
Posts: 2347
Loc: Dysart, Iowa
|
Lee did not say this head flows 350 cfm. But I believe he is supplying a flow test, or atleast I hope so.
Told him I would go thru the head to be sure parts are upto snuff, hate to see a loose keeper ruin the engine. He was ok with that. He is setting it up for the cams specs I gave him.
Maybe Larry or Hank could provide and worked up "194" head and show how they can be made to work. I would really like to see one work good.
Got a 3 weber(type) side draft carb setup coming. From 1/2 way around the world! How is that for support!
Thanks for all the contributions, just finished paying for the 292 dyno this weekend. The 250 will be more out of immediate pocket because of the shortblock build. It is for a good cause and glad I am able to offer up the service. Tom
|
|
Top
|
|
|
|
Moderator: Webmaster
|
|
