CFM and Volumetric Efficiency of a 300...

The Big Block of inline Ford sixes

Moderator: Mod Squad

CFM and Volumetric Efficiency of a 300...

Postby clintonvillian » Sun Jan 26, 2014 4:04 pm

Have you guys got any guesses on these numbers?

Especially the CFM, any ideas how much air a worked head can move?
clintonvillian
Registered User
 
Posts: 283
Joined: Wed Jun 15, 2011 8:33 pm

Re: CFM and Volumetric Efficiency of a 300...

Postby CNC-Dude » Sun Jan 26, 2014 5:46 pm

I have spoken to one of the racers on here that has a really good professionally ported head, big valves and the whole works and the limit seems to be....230-ish CFM! So a decent backyard port job might be up to 200 CFM.
A Rooster crows....
The Sun comes up....
He didn't cause it!
CNC-Dude
Registered User
 
Posts: 808
Joined: Wed Nov 19, 2008 7:06 pm
Location: N. Ga.

Re: CFM and Volumetric Efficiency of a 300...

Postby pmuller9 » Sun Jan 26, 2014 10:31 pm

Here is a stock 240 head and a CNC ported 300 carb head 2.02/1.60 valves


Image
Last edited by pmuller9 on Mon Jan 27, 2014 12:31 am, edited 6 times in total.
pmuller9
Registered User
 
Posts: 192
Joined: Tue Aug 06, 2013 12:33 am
Location: Spokane, WA

Re: CFM and Volumetric Efficiency of a 300...

Postby clintonvillian » Sun Jan 26, 2014 10:41 pm

Is that hand ported or on a cnc, efi head or carb???
clintonvillian
Registered User
 
Posts: 283
Joined: Wed Jun 15, 2011 8:33 pm

Re: CFM and Volumetric Efficiency of a 300...

Postby clintonvillian » Sun Jan 26, 2014 10:50 pm

My calculator says i need 9 psi to move 409 cfm to reach 300hp.
clintonvillian
Registered User
 
Posts: 283
Joined: Wed Jun 15, 2011 8:33 pm

Re: CFM and Volumetric Efficiency of a 300...

Postby CNC-Dude » Sun Jan 26, 2014 11:07 pm

We also dyno tested a turbo 250 over on Inliners that made 350 HP with only 5 psi boost. The head flowed 265 CFM on the intake and 180 CFM on the exhaust. The 292 we dyno tested made 300 HP N/A with the same head and only 9.2:1 compression.
A Rooster crows....
The Sun comes up....
He didn't cause it!
CNC-Dude
Registered User
 
Posts: 808
Joined: Wed Nov 19, 2008 7:06 pm
Location: N. Ga.

Re: CFM and Volumetric Efficiency of a 300...

Postby pmuller9 » Sun Jan 26, 2014 11:33 pm

clintonvillian wrote:Is that hand ported or on a cnc, efi head or carb???


CNC Ported 1986 Carb Head
pmuller9
Registered User
 
Posts: 192
Joined: Tue Aug 06, 2013 12:33 am
Location: Spokane, WA

Re: CFM and Volumetric Efficiency of a 300...

Postby pmuller9 » Sun Jan 26, 2014 11:45 pm

clintonvillian wrote:My calculator says i need 9 psi to move 409 cfm to reach 300hp.


Yes, that's 409 cfm going into the intake of the S/C but the pressure ratio at 9 psi is 1.6.
The actual flow going out the S/C and into the engine is 409/1.6 or 255 cfm.
pmuller9
Registered User
 
Posts: 192
Joined: Tue Aug 06, 2013 12:33 am
Location: Spokane, WA

Re: CFM and Volumetric Efficiency of a 300...

Postby Broncitis » Mon Jan 27, 2014 2:01 am

I would say 230/175 at .600 n/a is pretty far up there and it cost me plenty, but the performance is incredible.
69 Early bronco, 4.11, toploader 4speed, 68k 3inch body lift, ET about 50 something!!!
Broncitis
Registered User
 
Posts: 592
Joined: Thu Nov 23, 2006 12:36 am
Location: Raton, New Mexico

Re: CFM and Volumetric Efficiency of a 300...

Postby pmuller9 » Mon Jan 27, 2014 2:09 am

Broncitis wrote:I would say 230/175 at .600 n/a is pretty far up there and it cost me plenty, but the performance is incredible.
Which head did you start with and who did the port work?
pmuller9
Registered User
 
Posts: 192
Joined: Tue Aug 06, 2013 12:33 am
Location: Spokane, WA

Re: CFM and Volumetric Efficiency of a 300...

Postby CNC-Dude » Mon Jan 27, 2014 2:27 am

Broncitis wrote:I would say 230/175 at .600 n/a is pretty far up there and it cost me plenty, but the performance is incredible.

The racer I was mentioning has a head that is about that, maybe a little more. His was done by Arnold and was a 240 head. And your right, it cost big bucks to make a Ford head flow that much.
A Rooster crows....
The Sun comes up....
He didn't cause it!
CNC-Dude
Registered User
 
Posts: 808
Joined: Wed Nov 19, 2008 7:06 pm
Location: N. Ga.

Re: CFM and Volumetric Efficiency of a 300...

Postby clintonvillian » Mon Jan 27, 2014 11:25 am

pmuller9 wrote:
clintonvillian wrote:My calculator says i need 9 psi to move 409 cfm to reach 300hp.


Yes, that's 409 cfm going into the intake of the S/C but the pressure ratio at 9 psi is 1.6.
The actual flow going out the S/C and into the engine is 409/1.6 or 255 cfm.


What are you using for Volumetric efficiency? My calculations show theoretical to be 400cfm. 400/200 (actual cfm) is only 50%. That is boosting my levels to 22 psi!


OK, where did the 1.6 ratio come from, a map, which map are you using (I can't find a 4th gen map for a m112)?

So less volume coming out, but denser by a factor of 1.6?

Also since a good ported head will only move 230( 200 closer to real life) cfm, then 9 psi is not enough?

So I need 409/200 = 2.04 ratio....On a 5th generation map (mine is a 4th and I cant find one). That puts me around 58% efficiency, just under 8000 rpms on the blower?

Holy crap, I think I am starting to grasp this! The pressure is dictated in the intake by the increased density to get the same amount of air in the engine overcoming the head deficiencies.
clintonvillian
Registered User
 
Posts: 283
Joined: Wed Jun 15, 2011 8:33 pm

Re: CFM and Volumetric Efficiency of a 300...

Postby clintonvillian » Mon Jan 27, 2014 11:51 am

I think I messed up on the pressure ratio, I compared volume/volume when it should have been pressure......

Based on VE of 50% and 22psi boost: (22+14.7)= 2.5 which isnt even listed on the map

Am I screwing up on the VE? 50% is REALLY low?
clintonvillian
Registered User
 
Posts: 283
Joined: Wed Jun 15, 2011 8:33 pm

Re: CFM and Volumetric Efficiency of a 300...

Postby StrangeRanger » Mon Jan 27, 2014 3:55 pm

VE varies with RPM so it's not a single figure.
The VE vs. RPM curve looks roughly like the torque curve which come to think about it for a 300 would be fairly close to a single figure. I think you'll find the VE of a stock EFI 300 is somewhere around 67% @ the 3400 RPM HP peak and creeps up closer to 75% at the 2000 RPM torque peak
1996 F-150 (tow missile)
1993 Mustang 5.0 (hot rod and auto-x monster)
1982 Tiga Formula Ford (SCCA racecar)
2013 Hyundai Elantra Coupe (daily driver)
User avatar
StrangeRanger
VIP Member
 
Posts: 7990
Joined: Fri Nov 08, 2002 6:54 pm
Location: Copley, OH

Re: CFM and Volumetric Efficiency of a 300...

Postby clintonvillian » Mon Jan 27, 2014 4:11 pm

Please try to explain that further strange.............

VE is just a ratio of actual volume / theorhetical volume. That being stated if the max flow these guys are seeing on a head is a maximum of 230, and I am calculating for boost at 4500 rpm.

wouldn't the max VE be 230/400?
clintonvillian
Registered User
 
Posts: 283
Joined: Wed Jun 15, 2011 8:33 pm

Re: CFM and Volumetric Efficiency of a 300...

Postby pmuller9 » Mon Jan 27, 2014 5:28 pm

The head flow numbers I posted are only for a single port not all six ports.

The ability for an engine to fill a cylinder (VE) is a function of port and intake manifold flow characteristics along with cam timing versus engine displacement and rpm. Add exhaust system response and a bunch of other contributors.

It is measured realtime as actual airflow into the engine divided by the theoretical flow of (engine displacement)x(RPM)/2.
Most Dyno readouts will show this result.

You can calculate VE if you know the HP. VE = (9411 x HP x BSFC)/(CID x RPM)
BSFC for a naturally aspirated engine is around 0.5 and 0.65 for S/C
CID in our case is 300.

If you plug all the numbers in for a stock 300 you will see that StrangeRanger is real close at 67% at HP Peak and it moves up slightly as you approach peak torque. VE is max at torque peak.

With my ported head and cam combination, computer sim showed 325hp @ 5500 and 330 ft.lbs@ 3700
That is 90% VE @ peak hp and 92% VE @ Peak torque
pmuller9
Registered User
 
Posts: 192
Joined: Tue Aug 06, 2013 12:33 am
Location: Spokane, WA

Re: CFM and Volumetric Efficiency of a 300...

Postby clintonvillian » Mon Jan 27, 2014 5:50 pm

Do you all have any info / calculators / calculations for the effect of boost on torque? All I can find is HP stuff, and I could really care less about HP for this build.........I want the grunt!
clintonvillian
Registered User
 
Posts: 283
Joined: Wed Jun 15, 2011 8:33 pm

Re: CFM and Volumetric Efficiency of a 300...

Postby pmuller9 » Mon Jan 27, 2014 6:45 pm

clintonvillian wrote:Do you all have any info / calculators / calculations for the effect of boost on torque? All I can find is HP stuff, and I could really care less about HP for this build.........I want the grunt!


My last post is to help you understand and calculate VE. You will need VE for this calculator.
It was also to show that a stock head on stock engine has a VE in the mid 60s while a ported head on a street/strip engine has a VE in the low 90s.
If you put the ported head on a high rpm race engine, VE can exceed 100%.

You also asked about pressure ratios and related stuff. It looks like you got it.

The pressure ratio is the ratio increase in pressure over 1 atmosphere (14.7 + PSI)/14.7 at sea level. 9 psi = 1.61 PR.

The M112 Gen 4 is close enough to use the Gen 5 map. I see you noted that the M112 was not designed for high boost and the map quits vertically at a pressure ratio of 2 or 15 psi.

The pressure into the engine is reduced by the pressure drop of the intercooler. If you want 9 psi at the engine and the intercooler is dropping 1 psi then the S/C needs to supply 10 psi. The calculator adds the intercooler drop to the S/C pressure which increases the PR.

This calculator is designed for turbochargers but can be used for S/C application. Just ignore the turbine info.
It takes into account for everything. Have fun with it.

http://www.turbos.bwauto.com/aftermarke ... sin=92044&
pmuller9
Registered User
 
Posts: 192
Joined: Tue Aug 06, 2013 12:33 am
Location: Spokane, WA

Re: CFM and Volumetric Efficiency of a 300...

Postby clintonvillian » Mon Jan 27, 2014 9:03 pm

OK couple of setup questions............

My goal was to have a high torque value around 1500-1700 rpms for highway speeds. (2.73 rear, .063 OD). That way there would be enough torque to push it down the highway without having to downshift for slight grades. I am thinking that 3500-4500 is strictly the fun range, won't be seen a lot.

Based on that calculator and different configurations, at 1500 rpms and 5 psi I am around 330 ftlbs, is that enough to push it down the road without having to downshift at every slight grade (3500 lb vehicle, poor areo, and 30" tires??

I see that you were definitely right now, 2:1 on that compressor is more than sufficient to reach the boost levels I want and will still require a wastegate at anything above 3000 rpms to keep it at 10 psi. Question is, can I run that off of my 6V belt and pulley on the harmonic balancer that is also running the AC, Alternator, PS pump, without slippage without breaking or stretching the belt? I mean I wouldn't mind changing it every 10k miles or so, just don't want it to be an every other day thing.
clintonvillian
Registered User
 
Posts: 283
Joined: Wed Jun 15, 2011 8:33 pm

Re: CFM and Volumetric Efficiency of a 300...

Postby StrangeRanger » Mon Jan 27, 2014 10:52 pm

Ford gives 2 data points for the 300: 260 ft-lbs @ 2000 RPM and 150HP @ 3400 RPM
Because HP = T x RPM / 5252 you can calculate HP at 200 (99 HP) and the torque @ 3400 (232 ft-lbs.)

Plugging into pmuller9's equation VE = (9411 x HP x BSFC)/(CID x RPM)
VE @ 2000 = 77%
VE @ 3400 = 69%

His equation can also be re-written so it can be used be used to calculate VE from torque values since HP/RPM times a constant is torque

VE = 1.792 x T x BSFC / CID

From this version you can see that the VE curve will have the same shape as the torque.
1996 F-150 (tow missile)
1993 Mustang 5.0 (hot rod and auto-x monster)
1982 Tiga Formula Ford (SCCA racecar)
2013 Hyundai Elantra Coupe (daily driver)
User avatar
StrangeRanger
VIP Member
 
Posts: 7990
Joined: Fri Nov 08, 2002 6:54 pm
Location: Copley, OH

Re: CFM and Volumetric Efficiency of a 300...

Postby pmuller9 » Mon Jan 27, 2014 11:47 pm

StrangeRanger wrote:Ford gives 2 data points for the 300: 260 ft-lbs @ 2000 RPM and 150HP @ 3400 RPM
Because HP = T x RPM / 5252 you can calculate HP at 200 (99 HP) and the torque @ 3400 (232 ft-lbs.)

Plugging into pmuller9's equation VE = (9411 x HP x BSFC)/(CID x RPM)
VE @ 2000 = 77%
VE @ 3400 = 69%

His equation can also be re-written so it can be used be used to calculate VE from torque values since HP/RPM times a constant is torque

VE = 1.792 x T x BSFC / CID

From this version you can see that the VE curve will have the same shape as the torque.


Thanks StrangeRanger
I've never done the substitution for HP in the equation to actually show VE being directly proportional to Torque.
Cool stuff!!

Just a side note: The BSFC does change some over the rpm range because of A/F ratio change and spark timing.
pmuller9
Registered User
 
Posts: 192
Joined: Tue Aug 06, 2013 12:33 am
Location: Spokane, WA

Re: CFM and Volumetric Efficiency of a 300...

Postby pmuller9 » Tue Jan 28, 2014 1:10 am

clintonvillian wrote:OK couple of setup questions............

My goal was to have a high torque value around 1500-1700 rpms for highway speeds. (2.73 rear, .063 OD). That way there would be enough torque to push it down the highway without having to downshift for slight grades. I am thinking that 3500-4500 is strictly the fun range, won't be seen a lot.

Based on that calculator and different configurations, at 1500 rpms and 5 psi I am around 330 ftlbs, is that enough to push it down the road without having to downshift at every slight grade (3500 lb vehicle, poor areo, and 30" tires??

I see that you were definitely right now, 2:1 on that compressor is more than sufficient to reach the boost levels I want and will still require a wastegate at anything above 3000 rpms to keep it at 10 psi. Question is, can I run that off of my 6V belt and pulley on the harmonic balancer that is also running the AC, Alternator, PS pump, without slippage without breaking or stretching the belt? I mean I wouldn't mind changing it every 10k miles or so, just don't want it to be an every other day thing.


My 2001 F150 4 Door 5.4 has 350 ft.lbs @ 2500 rpm and the truck scales in at 5460 with me in it.
It has OD and is geared about the same as yours will be and it has no problem with moderate grades in OD.

My original statement about a 2:1 S/C drive ratio was incorrect and was made before I knew the S/C came off a Ford Lightning which has a drive ratio of 2.56.
Based on the Lightning advertised with 8 psi of manifold pressure, if you reduced the engine size from 330 to 300 the boost would be at 10 lbs providing the engines operate at the same VE.
[(8+14.7)/300] x 330 - 14.7 = 10.27 psi.

If you want to check it another way, looking at the M112 compressor map, at a pressure ratio of 1.7, find the intersecting point at 6000 rpm.
If you go straight down to the flow numbers at the bottom it should show around 530 cu meters/hour or 312 cfm.

The M112 Advertised displacement is 112 cu inches per revolution or 389 cfm @ 6000 rpm.
Actual Flow/Advertised Displacement or 312/389 = 80% VE
So the S/C is operating at 80% VE at a pressure ratio of 1.7

Using a drive ratio of 2.56, engine rpm = 6000/2.56 = 2344 rpm.
Using a ported head and a 90 % VE, CFM at 2344 rpm = 183.
S/C cfm/ engine cfm or 312/183 = Pressure Ratio of 1.7 or 10.29 lbs of boost
Looks like it still checks out.

The Lightning uses a separate belt just to drive the S/C and it has a very tight wrap by way of 2 idler pulleys.
So I would say you also need 2 belts, one for the S/C and one for the AC, Power Steering and Alternator
pmuller9
Registered User
 
Posts: 192
Joined: Tue Aug 06, 2013 12:33 am
Location: Spokane, WA

Re: CFM and Volumetric Efficiency of a 300...

Postby Broncitis » Tue Jan 28, 2014 1:49 am

My head was a 240 done by jerry Arnold, it cost me almost 1200 bucks less the rockers, I have a magnuson m112 direct mount carb or throttle body supercharger brand new, I think it is a good match for the 300, I see all the jumping around with the #'s that drives me a little crazy, in the real world I would choose a boost as a target with my build with the blower pulley being in the approximate middle, then you can move up are down to get it on spot without all the brainiacing, I nailed my m90 at 10 and 6 psi with pulleys the first time 3.4 and 3.8 respectively for the 200, but its not always the case, its not all that complicated.
69 Early bronco, 4.11, toploader 4speed, 68k 3inch body lift, ET about 50 something!!!
Broncitis
Registered User
 
Posts: 592
Joined: Thu Nov 23, 2006 12:36 am
Location: Raton, New Mexico

Re: CFM and Volumetric Efficiency of a 300...

Postby Broncitis » Tue Jan 28, 2014 1:57 am

Use an 8 rib belt.
69 Early bronco, 4.11, toploader 4speed, 68k 3inch body lift, ET about 50 something!!!
Broncitis
Registered User
 
Posts: 592
Joined: Thu Nov 23, 2006 12:36 am
Location: Raton, New Mexico

Re: CFM and Volumetric Efficiency of a 300...

Postby pmuller9 » Tue Jan 28, 2014 1:59 am

Broncitis wrote:My head was a 240 done by jerry Arnold, it cost me almost 1200 bucks less the rockers, I have a magnuson m112 direct mount carb or throttle body supercharger brand new, I think it is a good match for the 300, I see all the jumping around with the #'s that drives me a little crazy, in the real world I would choose a boost as a target with my build with the blower pulley being in the approximate middle, then you can move up are down to get it on spot without all the brainiacing, I nailed my m90 at 10 and 6 psi with pulleys the first time 3.4 and 3.8 respectively for the 200, but its not always the case, its not all that complicated.


Thanks for another view point.
How are you mounting the crank pulley for the supercharger to the 300 crank hub?
pmuller9
Registered User
 
Posts: 192
Joined: Tue Aug 06, 2013 12:33 am
Location: Spokane, WA

Re: CFM and Volumetric Efficiency of a 300...

Postby Broncitis » Tue Jan 28, 2014 2:17 am

I bought this blower a few years ago and have done nothing with it yet, but have the 300 in mind, have not researched my options as for as pulleys go, but I'm pretty sure I would run e-85 with a carb direct mount to blower for the latent heat of evaporation and octane if available.
69 Early bronco, 4.11, toploader 4speed, 68k 3inch body lift, ET about 50 something!!!
Broncitis
Registered User
 
Posts: 592
Joined: Thu Nov 23, 2006 12:36 am
Location: Raton, New Mexico

Re: CFM and Volumetric Efficiency of a 300...

Postby Broncitis » Tue Jan 28, 2014 2:32 am

That 2.56 sounds like a good starting point, if he gets this thing together right, it will pull like a mule on crack, I couldn't believe the little 200 at 10lbs of boost, but the 300 will cause great damage to bents set up like this. One day I may do it instead of talking about it.
69 Early bronco, 4.11, toploader 4speed, 68k 3inch body lift, ET about 50 something!!!
Broncitis
Registered User
 
Posts: 592
Joined: Thu Nov 23, 2006 12:36 am
Location: Raton, New Mexico

Re: CFM and Volumetric Efficiency of a 300...

Postby Broncitis » Tue Jan 28, 2014 2:48 am

I used asp to custom build a pulley to mount to my balancer on the 200 and the same can be done on the 300 very easily and then directly to the blower with a tensioner somewhere in between, I think it was 275 bucks worth, it may be the simple way, but others may have done differently or have a better idea.
69 Early bronco, 4.11, toploader 4speed, 68k 3inch body lift, ET about 50 something!!!
Broncitis
Registered User
 
Posts: 592
Joined: Thu Nov 23, 2006 12:36 am
Location: Raton, New Mexico

Re: CFM and Volumetric Efficiency of a 300...

Postby clintonvillian » Tue Jan 28, 2014 10:12 am

Interesting that you mentioned edis and sequential fuel injection. Megasquirt states that it needs a cam position sensor, and not the crank........ im not sure that would matter since ours is gear driven??

Mine is an efi engine and uses tfi, megasquirt will run that system, i am just not sure it is as accurate as edis? If i were to rum tfi it would eliminate the need for a trigger wheel and still have a seperate coil pack.

I am also debating going to an enginequest head. I have a brand new 240 head on a shelf i had considered using but may sell now, and of course the stock efi head. I figure selling my heads, and the install of hardened seats would offset the cost of a new head.
clintonvillian
Registered User
 
Posts: 283
Joined: Wed Jun 15, 2011 8:33 pm

Re: CFM and Volumetric Efficiency of a 300...

Postby pmuller9 » Tue Jan 28, 2014 3:25 pm

clintonvillian wrote:Interesting that you mentioned edis and sequential fuel injection. Megasquirt states that it needs a cam position sensor, and not the crank........ im not sure that would matter since ours is gear driven??

Mine is an efi engine and uses tfi, megasquirt will run that system, i am just not sure it is as accurate as edis? If i were to rum tfi it would eliminate the need for a trigger wheel and still have a seperate coil pack.

I am also debating going to an enginequest head. I have a brand new 240 head on a shelf i had considered using but may sell now, and of course the stock efi head. I figure selling my heads, and the install of hardened seats would offset the cost of a new head.


The edis uses the waste spark coil packs so it doesn't need a cam sync signal but the Megasquirt still needs the cam sync signal to operate sequential fuel injection.
The crank trigger gear gives more resolution than the 4 pulse per crank revolution distributor signal.

It looks like the MS2 and MS3 will work with the TFI distributor.

Do you have a MegaSquirt unit yet?

The Enginequest head looks like a heavy duty piece.
How much does it cost?
pmuller9
Registered User
 
Posts: 192
Joined: Tue Aug 06, 2013 12:33 am
Location: Spokane, WA

Re: CFM and Volumetric Efficiency of a 300...

Postby clintonvillian » Tue Jan 28, 2014 3:53 pm

I have not purchased the system yet.

Is the edis better than the tfi, will the tfi support sequential injection?

Engine quest head was aroumd 500-600 depending on shipping. Hmm i wonder if the hardened seats have enough material to cut the larger valvea in?
clintonvillian
Registered User
 
Posts: 283
Joined: Wed Jun 15, 2011 8:33 pm

Re: CFM and Volumetric Efficiency of a 300...

Postby pmuller9 » Tue Jan 28, 2014 4:36 pm

clintonvillian wrote:I have not purchased the system yet.

Is the edis better than the tfi, will the tfi support sequential injection?

Engine quest head was aroumd 500-600 depending on shipping. Hmm i wonder if the hardened seats have enough material to cut the larger valvea in?


The edis is a Stand Alone ignition system. You want to be able to control the ignition timing with your aftermarket EFI system because it will control the timing under boost. The only thing that is kept from the OEM edis system is the 36-1 tooth trigger gear that mounts on the crank hub. Then you also need the cam sync signal from the distributor to identify cylinder #1 for sequential fuel injection

The TFI distributor has a slotted ring where 5 of the slots are the same width and one of the slots is narrow. The narrow slot indicates cylinder #1 but you need a system that can interpret the signal.

The edis 36 tooth crank rings gives the EFI system a timing reference pulse every 10 degrees of crankshaft rotation,
the TFI distributor gives a pulse every 90 degrees of crank rotation. You get much better accuracy with interpolation between 10 degrees rather than 90 degrees especially when the engine rpm is changing rapidly during acceleration.

I prefer an aftermarket system that includes everything you need, from the crank trigger wheel and pickup to the coil packs with the injector drivers (both low and high impedance) and the coil pack drivers - all in 1 unit.

Hmm i wonder if the hardened seats have enough material to cut the larger valvea in?


Good question. I don't know
Last edited by pmuller9 on Tue Jan 28, 2014 9:35 pm, edited 2 times in total.
pmuller9
Registered User
 
Posts: 192
Joined: Tue Aug 06, 2013 12:33 am
Location: Spokane, WA

Re: CFM and Volumetric Efficiency of a 300...

Postby CNC-Dude » Tue Jan 28, 2014 5:20 pm

clintonvillian wrote: Hmm i wonder if the hardened seats have enough material to cut the larger valve in?


There should be some extra margin to cut for a larger size, but unless you also enlarge the bowl as well, just going larger with the valve size wont help much.
A Rooster crows....
The Sun comes up....
He didn't cause it!
CNC-Dude
Registered User
 
Posts: 808
Joined: Wed Nov 19, 2008 7:06 pm
Location: N. Ga.

Re: CFM and Volumetric Efficiency of a 300...

Postby clintonvillian » Tue Jan 28, 2014 9:20 pm

Outta curiosity how come you ordered custom piatons for the students 300 since its not being boosted?
clintonvillian
Registered User
 
Posts: 283
Joined: Wed Jun 15, 2011 8:33 pm

Re: CFM and Volumetric Efficiency of a 300...

Postby pmuller9 » Tue Jan 28, 2014 9:31 pm

clintonvillian wrote:Outta curiosity how come you ordered custom piatons for the students 300 since its not being boosted?


I'm using the 6.8" 240 rods to reduce side loading and the shorter piston will be much lighter than stock to reduce rod loading at 5500 rpm.
I wanted 9.75 compression ratio using a Spherical dish at zero deck clearance.
I also wanted 4032 alloy forged pistons that will still allow close cylinder wall clearance but not be as brittle as hyperuetectics.
pmuller9
Registered User
 
Posts: 192
Joined: Tue Aug 06, 2013 12:33 am
Location: Spokane, WA


Return to 240-300 "Big Block" Six Performance

Who is online

Users browsing this forum: Yahoo [Bot] and 5 guests