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Gains switching to larger intake valve #468391 09/14/09 10:13 PM 09/14/09 10:13 PM
Joined: Dec 2004 Posts: 415 New Braunfels, TX 4 416challenger OP mopar
416challenger OP mopar 4 Joined: Dec 2004 Posts: 415 New Braunfels, TX	I will be freshening up my motor after this season and I was considering going from a 2.02 valve to a 2.05. What kind of gains if any can be had? The heads are Edelbrock RPM that flow the as followed- Intake Exhaust .100" 82.8 N/A .200" 149.0 112.1 .300" 211.2 169.3 .400" 255.6 203.2 .450" 269.4 218.0 .500" 276.3 226.0 .550" 281.5 229.8 .600" 284.6 231.2 .650" 284.6 231.5 .700" 284.6 232.9 The cam is 262in 268ex @.050 w/ 675" lift. I would like to run 7.00 in the heat, I normally run around 7.09 @ 3800 da. Has anyone made a similar change, if so what kind of results?

Re: Gains switching to larger intake valve [Re: 416challenger] #468392 09/14/09 10:19 PM 09/14/09 10:19 PM
Joined: Feb 2004 Posts: 4,501 Gainesville,FL G goldmember master
goldmember master G Joined: Feb 2004 Posts: 4,501 Gainesville,FL	Depends on the port.Simply installing a larger valve in the same port often won't help.

Re: Gains switching to larger intake valve [Re: 416challenger] #468393 09/14/09 10:26 PM 09/14/09 10:26 PM
Joined: Jul 2006 Posts: 4,595 On the south side of Nowhere S S/ST 3040 master
S/ST 3040 master S Joined: Jul 2006 Posts: 4,595 On the south side of Nowhere	Quote: I will be freshening up my motor after this season and I was considering going from a 2.02 valve to a 2.05. What kind of gains if any can be had? The heads are Edelbrock RPM that flow the as followed- Intake Exhaust .100" 82.8 N/A .200" 149.0 112.1 .300" 211.2 169.3 .400" 255.6 203.2 .450" 269.4 218.0 .500" 276.3 226.0 .550" 281.5 229.8 .600" 284.6 231.2 .650" 284.6 231.5 .700" 284.6 232.9 The cam is 262in 268ex @.050 w/ 675" lift. I would like to run 7.00 in the heat, I normally run around 7.09 @ 3800 da. Has anyone made a similar change, if so what kind of results? 82.8 CFM @ .100" lift??

Re: Gains switching to larger intake valve [Re: goldmember] #468394 09/14/09 10:28 PM 09/14/09 10:28 PM
Joined: Jan 2003 Posts: 8,022 Tulsa OK Bad340fish master
Bad340fish master Joined: Jan 2003 Posts: 8,022 Tulsa OK	On my ported X heads I changed from stock 2.02 valves to a race style 2.05 intake and it picked up .2, I don't recall how much MPH it gained. I also replaced the stock exhaust valves with SS valves as well so there might be some gain from that. 68 Barracuda Formula S 340

Re: Gains switching to larger intake valve [Re: Bad340fish] #468395 09/14/09 11:01 PM 09/14/09 11:01 PM
Joined: Feb 2004 Posts: 4,501 Gainesville,FL G goldmember master
goldmember master G Joined: Feb 2004 Posts: 4,501 Gainesville,FL	You bring up a good point. I have seen gains of .2 in the 1/8mile with a simple valve angle change,same valves. It's obvious that it was on different days so weather and track conditions cannot be ruled out. Last edited by goldmember; 09/14/09 11:02 PM.

Re: Gains switching to larger intake valve [Re: S/ST 3040] #468396 09/14/09 11:29 PM 09/14/09 11:29 PM
Joined: Dec 2004 Posts: 415 New Braunfels, TX 4 416challenger OP mopar
416challenger OP mopar 4 Joined: Dec 2004 Posts: 415 New Braunfels, TX	S/ST 3040-What did you mean by your comment???

Re: Gains switching to larger intake valve [Re: 416challenger] #468397 09/14/09 11:42 PM 09/14/09 11:42 PM
Joined: Jul 2006 Posts: 4,595 On the south side of Nowhere S S/ST 3040 master
S/ST 3040 master S Joined: Jul 2006 Posts: 4,595 On the south side of Nowhere	Quote: S/ST 3040-What did you mean by your comment??? 82.8 CFM @ .100" is not even in the ball park. I've been through this before and I've never seen a 2.02" valve flow more than 66 CFM @ .100" Being that far off at .100" lift, only makes me question the 284+ at higher lifts. I've seen similar flow numbers before, posted here. Contrary to popular belief, this is a subject I know a little about.

Re: Gains switching to larger intake valve [Re: S/ST 3040] #468398 09/14/09 11:47 PM 09/14/09 11:47 PM
Joined: Dec 2004 Posts: 415 New Braunfels, TX 4 416challenger OP mopar
416challenger OP mopar 4 Joined: Dec 2004 Posts: 415 New Braunfels, TX	S/ST 3040- I was not aware that this number is abnormal(incorrect), that is why I asked. It is what is listed on the flow sheet. The heads were ported by a respected member from this site, so I assume the numbers were correct.

Re: Gains switching to larger intake valve [Re: 416challenger] #468399 09/15/09 12:01 AM 09/15/09 12:01 AM
Joined: Jul 2006 Posts: 4,595 On the south side of Nowhere S S/ST 3040 master
S/ST 3040 master S Joined: Jul 2006 Posts: 4,595 On the south side of Nowhere	Unless you send them back to the same guy to flow them with the 2.05 valves, you are going to be very disappointed. I can tell from your flow sheet. 2.02" valve is capable of flowing at least 324 CFM @ .700" 2.05" valve is OK in an Edelbrock head but, you won't see any improvement unless the valve job on 2.02" seat was no good to begin with. This is a set I did with the valves listed: ...........INTAKE........................ EXHAUST .100"_____64.1___________________54.6 .200"____131.6__________________118.6 .300"____194.4__________________158.6 .400"____242.5__________________177.1 .500"____270.8__________________192.4 .550"____279.3__________________199.5 .600"____282.2__________________204.4 2.055" IN x 1.600" EX

Re: Gains switching to larger intake valve [Re: S/ST 3040] #468400 09/15/09 12:08 AM 09/15/09 12:08 AM
Joined: Dec 2004 Posts: 415 New Braunfels, TX 4 416challenger OP mopar
416challenger OP mopar 4 Joined: Dec 2004 Posts: 415 New Braunfels, TX	I am not hung up on the flow numbers. I am just looking for somewhere in my combination that I can make some improvement with minimal investment.

Re: Gains switching to larger intake valve [Re: 416challenger] #468401 09/15/09 12:13 AM 09/15/09 12:13 AM
Joined: Jul 2006 Posts: 4,595 On the south side of Nowhere S S/ST 3040 master
S/ST 3040 master S Joined: Jul 2006 Posts: 4,595 On the south side of Nowhere	Give us the whole build. Plus transmission, converter, race weight, gear and tire size.

Re: Gains switching to larger intake valve [Re: S/ST 3040] #468402 09/15/09 07:42 AM 09/15/09 07:42 AM
Joined: Dec 2004 Posts: 415 New Braunfels, TX 4 416challenger OP mopar
416challenger OP mopar 4 Joined: Dec 2004 Posts: 415 New Braunfels, TX	My combination is-73 Challenger, 418 cid, 11.55:1 comp, Edelebrock RPM heads, Vitor intake, 950HP carb, 262in 268ex 675" lift, 727 tran, 9 1/2" 4800 converter, Dana 60 w/ 4.10 gears, 28 x 12.5 ET Street tire, and the weight is 3720 w/ driver. I have ran a best of 6.92 @97.2 and 10.98 @120.7 w/ 1.50 60' time.

Re: Gains switching to larger intake valve [Re: 416challenger] #468403 09/15/09 09:09 AM 09/15/09 09:09 AM
Joined: Jul 2006 Posts: 4,595 On the south side of Nowhere S S/ST 3040 master
S/ST 3040 master S Joined: Jul 2006 Posts: 4,595 On the south side of Nowhere	Honestly, that is not bad for 11.55 compression and 3720 lbs. (505 HP) Since you mentioned "improvement with minimal investment", I'd start looking for places to take out weight. That's about as cheap as you can get.......and effective. Everything else looks pretty decent together. Maybe another 1.5 point compression with another 10� cam, an 8' converter in a 2.74 low gear 904. Nothing really as cost effective as whittling down the weight. After I got as much weight out of it, as I could, then I'd swap to a 2.74 904 with a matching 8" converter. Only then would I start messing with the engine. The weight alone (200 lbs.) should get you 7.0s. Good luck.

Re: Gains switching to larger intake valve [Re: S/ST 3040] #468404 09/15/09 09:33 AM 09/15/09 09:33 AM
Joined: Mar 2004 Posts: 2,475 SW Ohio C cgall top fuel
cgall top fuel C Joined: Mar 2004 Posts: 2,475 SW Ohio	Probably no gain unless you unshroud the valve by machining the combustion chamber.

Re: Gains switching to larger intake valve [Re: cgall] #468405 09/15/09 10:00 AM 09/15/09 10:00 AM
Joined: Mar 2005 Posts: 2,172 Ohio T theclutcher top fuel
theclutcher top fuel T Joined: Mar 2005 Posts: 2,172 Ohio	Quote: Probably no gain unless you unshroud the valve by machining the combustion chamber. if that is shrouded, you can expect very little then bore size comes into play. imo...

Re: Gains switching to larger intake valve [Re: theclutcher] #468406 09/15/09 10:18 AM 09/15/09 10:18 AM
Joined: Jul 2006 Posts: 4,595 On the south side of Nowhere S S/ST 3040 master
S/ST 3040 master S Joined: Jul 2006 Posts: 4,595 On the south side of Nowhere	Quote: Quote: Probably no gain unless you unshroud the valve by machining the combustion chamber. if that is shrouded, you can expect very little then bore size comes into play. imo... Anytime I've tried unshrouding the intake valve (straight wall side) on an OEM head, it hurt flow. I haven't tried it on the RPM though. 5483757-DSCN1743.JPG (21 downloads)

Re: Gains switching to larger intake valve [Re: 416challenger] #468407 09/15/09 10:20 AM 09/15/09 10:20 AM
Joined: Feb 2003 Posts: 12,675 Columbia, CT M moper I Live Here
moper I Live Here M Joined: Feb 2003 Posts: 12,675 Columbia, CT	Quote: Intake Exhaust .100" 82.8 N/A .200" 149.0 112.1 .300" 211.2 169.3 .400" 255.6 203.2 .450" 269.4 218.0 .500" 276.3 226.0 .550" 281.5 229.8 .600" 284.6 231.2 .650" 284.6 231.5 .700" 284.6 232.9 The cam is 262in 268ex @.050 w/ 675" lift. If the port already stalls at .550 then adding more valve without adding port volume ahead of it isn't going to do much. I don't think shrouding is an issue. Or it's less of one than many think. I am curious tho... with those flow numbers, why such a small duration and huge lift? I would think more power will be made staying in the .650 range but adding another 15�-20� of duration at .050. I wouldnt have specd a cam any taller than .630 for those heads. Well, art is art, isn't it? Still, on the other hand, water is water! And east is east and west is west and if you take cranberries and stew them like applesauce they taste much more like prunes than rhubarb does. Now, uh... Now you tell me what you know.

Re: Gains switching to larger intake valve [Re: moper] #468408 09/15/09 01:12 PM 09/15/09 01:12 PM
Joined: Dec 2004 Posts: 415 New Braunfels, TX 4 416challenger OP mopar
416challenger OP mopar 4 Joined: Dec 2004 Posts: 415 New Braunfels, TX	The car runs on pump gas, so I really do not want to raise the compression any more. I was kind of leaning toward lightening it up. I have a steel hood and will probably go to a fiberglass hood. I also will be going to a 29.5" x 10.5" ET Drag and was thinking about a low gear set in the transmission. Anyone know the weight of a steel Challenger hood? Moper- The only reason for the high lift is I reused the 1.6 rockers that I had, with 1.5 I would have 632" lift.

Re: Gains switching to larger intake valve [Re: 416challenger] #468409 09/15/09 01:21 PM 09/15/09 01:21 PM
Joined: Jul 2006 Posts: 4,595 On the south side of Nowhere S S/ST 3040 master
S/ST 3040 master S Joined: Jul 2006 Posts: 4,595 On the south side of Nowhere	At 3720 lbs. there should be plenty of places to remove weight without spending any money. It obviously gets harder (and more expensive) the lighter you get. Going up 1.5" in tire will lower your drive shaft RPM over 300 RPM at the same speed. Wrong direction, I think. With 4% slip, I have you figured at about 6250 engine RPM, currently.

Re: Gains switching to larger intake valve [Re: S/ST 3040] #468410 09/16/09 09:10 AM 09/16/09 09:10 AM
Joined: Mar 2005 Posts: 2,172 Ohio T theclutcher top fuel
theclutcher top fuel T Joined: Mar 2005 Posts: 2,172 Ohio	Quote: Quote: Quote: Probably no gain unless you unshroud the valve by machining the combustion chamber. if that is shrouded, you can expect very little then bore size comes into play. imo... Anytime I've tried unshrouding the intake valve (straight wall side) on an OEM head, it hurt flow. I haven't tried it on the RPM though. That is interesting, Have only seen the opposite.

Re: Gains switching to larger intake valve [Re: theclutcher] #468411 09/16/09 09:37 AM 09/16/09 09:37 AM
Joined: Jul 2006 Posts: 4,595 On the south side of Nowhere S S/ST 3040 master
S/ST 3040 master S Joined: Jul 2006 Posts: 4,595 On the south side of Nowhere	Quote: Quote: Quote: Quote: Probably no gain unless you unshroud the valve by machining the combustion chamber. if that is shrouded, you can expect very little then bore size comes into play. imo... Anytime I've tried unshrouding the intake valve (straight wall side) on an OEM head, it hurt flow. I haven't tried it on the RPM though. That is interesting, Have only seen the opposite. Hmmmm..........3 notebooks full notes and a flow bench is pretty handy. 5485887-DSCN1396.JPG (24 downloads)

Re: Gains switching to larger intake valve [Re: S/ST 3040] #468412 09/16/09 09:52 AM 09/16/09 09:52 AM
Joined: Mar 2005 Posts: 2,172 Ohio T theclutcher top fuel
theclutcher top fuel T Joined: Mar 2005 Posts: 2,172 Ohio	Quote: Quote: Quote: Quote: Quote: Probably no gain unless you unshroud the valve by machining the combustion chamber. if that is shrouded, you can expect very little then bore size comes into play. imo... Anytime I've tried unshrouding the intake valve (straight wall side) on an OEM head, it hurt flow. I haven't tried it on the RPM though. That is interesting, Have only seen the opposite. Hmmmm..........3 notebooks full notes and a flow bench is pretty handy. cant argue with that, just the few Ive had experience with always picked up, big or small block when opening up that area. wonder what the difference could be?

Re: Gains switching to larger intake valve [Re: theclutcher] #468413 09/16/09 10:04 AM 09/16/09 10:04 AM
Joined: Jul 2006 Posts: 4,595 On the south side of Nowhere S S/ST 3040 master
S/ST 3040 master S Joined: Jul 2006 Posts: 4,595 On the south side of Nowhere	Scott.....I know the OEM big block heads do like opening that up, the more, the better, I understand but, it always screws up the high lift flow on my small block heads. Dwayne Porter and I discussed this once in conversation as, we both found the same thing.

Re: Gains switching to larger intake valve [Re: S/ST 3040] #468414 09/17/09 08:59 AM 09/17/09 08:59 AM
Joined: Mar 2005 Posts: 2,172 Ohio T theclutcher top fuel
theclutcher top fuel T Joined: Mar 2005 Posts: 2,172 Ohio	Hi Vic. At what lifts you see the reduction? Would not come into play too much if cam doesnt see time spent at that lift point. wondering if plusses if any at low lift more than offset the loss at high point. what have you seen?

Re: Gains switching to larger intake valve [Re: theclutcher] #468415 09/17/09 09:18 AM 09/17/09 09:18 AM
Joined: Feb 2003 Posts: 4,953 Houston, Texas TheOtherDodge master
TheOtherDodge master Joined: Feb 2003 Posts: 4,953 Houston, Texas	Hey Josh! Long time no talk! I think switching to the 2.05 valve is more expensive/time consuming than the improvement you will see (valve job, cut seats, new valve, set up springs, intake gaskets, head gaskets, antifreeze, oil, etc). I would concentrate on weight, particularly the hood where you will get a lot of weight off the nose. Tell your dad "hi" for me!

Re: Gains switching to larger intake valve [Re: theclutcher] #468416 09/17/09 09:31 AM 09/17/09 09:31 AM
Joined: Jul 2006 Posts: 4,595 On the south side of Nowhere S S/ST 3040 master
S/ST 3040 master S Joined: Jul 2006 Posts: 4,595 On the south side of Nowhere	OEM SB Casting #974 Manley Pro-Flo 2.02" x 30� BC .............BEFORE.........................................AFTER .100"_____62.0____________________________62.4 .200"____127.3___________________________128.9 .300"____188.9___________________________192.1 .400"____241.8___________________________240.2 .500"____269.8___________________________268.0 .550"____268.0___________________________** .600"____269.2___________________________266.2 .650"____269.9___________________________268.3 .700"____273.3___________________________268.3 ** - Turbulent/Noisy

Re: Gains switching to larger intake valve [Re: S/ST 3040] #468417 09/17/09 09:34 AM 09/17/09 09:34 AM
Joined: May 2004 Posts: 1,151 Las Vegas A afxcoronet super stock
afxcoronet super stock A Joined: May 2004 Posts: 1,151 Las Vegas	Josh, just leave it alone, and get started on the Dart... Taking over the World one win light at a time.

Re: Gains switching to larger intake valve [Re: TheOtherDodge] #468418 09/17/09 12:50 PM 09/17/09 12:50 PM
Joined: Dec 2004 Posts: 415 New Braunfels, TX 4 416challenger OP mopar
416challenger OP mopar 4 Joined: Dec 2004 Posts: 415 New Braunfels, TX	James- I figured since I was already going to be freshing the motor I would ask the question, but It sounds like it isn't a worth while investment. Now I just have to find a hood. Curtis- The Dart isn't going to happen anytime soon, we just put Mackenzie is preschool.

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