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homeboysduster
08-26-2012, 05:30 PM
a fresh thread to finish knightmoves. to recap the build knightmoves started out as a 91 daytona ES 3.0 5 speed. I brought it back from a VERY bad rust infestation to a great looking car, just to find out rust had gotten up high into the fire wall area where I couldn't see and had to start over. so here comes knightmoves2.0 a 87 daytona turbo z T top car with very little rust issues. this is the current car. over the last 3 years I have built 4 engines for the car and was never satisfied with them. the last engine a 10:1 twin throttle bodied motor I was forced to sell due to a very severe storm that destroyed 3 trees and part of my house. I had to sell the motor and some other stuff to pay for repairs. so that left me with no motor. I am now working on a 3.5 DOHC 6G74 motor to go into knightmoves. it is the only motor i have and will be posting here with updates. here are some pics of the engine and where it stands now.

home coming!
https://sphotos-b.xx.fbcdn.net/hphotos-prn1/s720x720/561543_351794914901904_156344198_n.jpg

https://sphotos-b.xx.fbcdn.net/hphotos-ash3/574505_351794961568566_1886828992_n.jpg

forged crank!!! and 4 bolt main!!

https://sphotos-b.xx.fbcdn.net/hphotos-ash3/558208_351795044901891_57488568_n.jpg


cleaned up!!

https://sphotos-a.xx.fbcdn.net/hphotos-ash3/527221_351795081568554_2013600463_n.jpg

https://sphotos-a.xx.fbcdn.net/hphotos-ash4/402810_351795111568551_959586297_n.jpg

newly powder coated VC's!!!

https://sphotos-a.xx.fbcdn.net/hphotos-snc6/217879_351795154901880_1217196789_n.jpg

new intake!!
https://sphotos-a.xx.fbcdn.net/hphotos-ash4/376621_351795221568540_208838091_n.jpg

https://sphotos-b.xx.fbcdn.net/hphotos-ash4/320237_351795281568534_1647940745_n.jpg

john1320
08-27-2012, 04:42 PM
That intake is absolutely beautiful, a great start to say the least

turbovanmanČ
08-28-2012, 06:44 PM
No doubt, kinda looks like the Yamaha SHO intake. :thumb:

omni_840
08-28-2012, 07:58 PM
Nice start! Looking forward to more progress:)

homeboysduster
08-28-2012, 08:13 PM
thanks guys!! it will have twin turbo's soon!!!

cordes
08-28-2012, 09:57 PM
Edited for real official Knightmoves theme song.


http://www.youtube.com/watch?v=J-tvJcTPxHc


That intake is awesome for sure. I really like what you've done with it.

homeboysduster
08-28-2012, 09:59 PM
This is the car's theme song right?


http://www.youtube.com/watch?v=bqwfaxYAH5o


That intake is awesome for sure. I really like what you've done with it.

thanks,but no. the cars name came from a knight moving on the enemy!!! seek and destroy!!!

cordes
08-28-2012, 10:10 PM
Unfortunate, but Seek and Destroy it is!

MC#4
08-28-2012, 11:21 PM
hahahahahah, I always figured it was named after bob seger's song too! ♫ Workin on knightmoves ♫ It fits so perfect.

That's ok, still a cool project :)

cordes
08-28-2012, 11:38 PM
hahahahahah, I always figured it was named after bob seger's song too! ♫ Workin on knightmoves ♫ It fits so perfect.

That's ok, still a cool project :)

And you're the predecessor to the MC5! We've got a rock and roll theme in this thread for sure! I can't wait to see this thing in action. I'm really excited about that intake.

homeboysduster
08-29-2012, 03:10 PM
got my 2 52mm throttle bodies in today!!! I will powder coat these to look better than they did when Ma Mopar made them!!!

https://sphotos-a.xx.fbcdn.net/hphotos-ash4/s720x720/418623_352798841468178_1793956022_n.jpg

Rrider
08-29-2012, 03:36 PM
Niiiice!!

Twin GT30?

homeboysduster
08-29-2012, 03:38 PM
Niiiice!!

Twin GT30?
not quite!!!LOL no Mitsubishi TEO4H yes a T1 turbo! they are bigger than the turbo's installed on the dodge stealth R/T twin turbo 3.0!!!

john1320
08-29-2012, 05:25 PM
I could imagine using KMP's logs. Instead of the single turbo mid-pipe, you could actually run flanged pipes up (*where KMP's turbo mid-pipe would locate a single) to where you would merge the exhaust discharge sides of both turbos using a 2 to 1 weld el, welded to Chrysler style discharge flanges on both snails. (divorced smaller weld el for ext gate) The plumbing for the intake and discharge for cold side might brick wall this, but you are very inventive at these challenges! Are you still opting for modified tube headers with low-mounts and recovery pump? (or are they high enough for gravity drain on the 3.5?)

RoadWarrior222
08-29-2012, 07:10 PM
This has all the signs of being completely insane.... I like it.

homeboysduster
08-29-2012, 07:29 PM
This has all the signs of being completely insane.... I like it.
thanks!!! I have to build a few parts to make this work but nothing major! I have to make a set of adapters for the manifolds to mount the turbos. once that is done i can ship my heads out to Ed!!!

STLShelbyZ
08-31-2012, 12:19 AM
Looking good Bobby! This is definitely as crazy as it gets haha.

RoadWarrior222
08-31-2012, 06:37 AM
I was reading yesterday about how how 3 cyls of a V6 are PARTICULARLY good at pumping a helmholtz resonator type of intake, which whether you intended it or not, is what yours will do. The thing is though with being such a large diameter, I think it will resonate quite low down, which might make for some slightly strange low down behavior, like you get a torque hump not far off idle, leading to harsh tip in, or that kicks your tires loose prematurely. So just thinking, that if I were "copying" you, that I'd try and brain out the math for a diameter such that the intake came in tune around 2500ish and took me into boost with less lag, rather than what might be a pump dump lag boost kind of feel.

homeboysduster
08-31-2012, 09:08 AM
I was reading yesterday about how how 3 cyls of a V6 are PARTICULARLY good at pumping a helmholtz resonator type of intake, which whether you intended it or not, is what yours will do. The thing is though with being such a large diameter, I think it will resonate quite low down, which might make for some slightly strange low down behavior, like you get a torque hump not far off idle, leading to harsh tip in, or that kicks your tires loose prematurely. So just thinking, that if I were "copying" you, that I'd try and brain out the math for a diameter such that the intake came in tune around 2500ish and took me into boost with less lag, rather than what might be a pump dump lag boost kind of feel.
my first intake was a N/A intake and was 4 inches in diameter. this one is only 3 inches and is 11 inches long. so it is a little on the small side. all my innercooling pipe will be 2 inch as well as the innercooler in lets and out lets. I choose 52mm throttle bodies so the velocity will remain high. the plan is to run the car off idle to about 6500RPM. I only have a 1/8th mile track here so when i do go to the trace this motor should perform well. see thid is a cruzer and a part time drag car. a toy!!!LOL thid id my first turbo car. so this is a learning experence. so i look forward to your comments and ideas!

homeboysduster
08-31-2012, 04:18 PM
https://sphotos-b.xx.fbcdn.net/hphotos-ash3/582777_353540901393972_163730572_n.jpg

31"x11"x3" GOD speed innercooler!!!!

homeboysduster
09-01-2012, 06:39 PM
https://sphotos-b.xx.fbcdn.net/hphotos-snc7/s720x720/408202_353948494686546_2092954967_n.jpg
got my T1 turbo's today!!! these will be rebuilt and heat coated hot side and powder coated in the boost side!

homeboysduster
09-05-2012, 03:16 PM
I pulled my pistons today. and as I expected the ring gap was to small!!! only 0.012 inches! new rings it is!!!
https://sphotos-b.xx.fbcdn.net/hphotos-ash3/523097_355306304550765_1110556368_n.jpg

MC#4
09-05-2012, 06:37 PM
Well if they are too small why not just open them up to where you want em? Aren't you going with file fit rings anyway?

Sundance 6g72
09-05-2012, 07:56 PM
i assume the block is getting honed anyways? good looking out on the new rings. Also, if i had to make a guess, this is a 10:1cr engine. low boost or alky injection would be required. That or running race fuel or e85.



not quite!!!LOL no Mitsubishi TEO4H yes a T1 turbo! they are bigger than the turbo's installed on the dodge stealth R/T twin turbo 3.0!!!


my first intake was a N/A intake and was 4 inches in diameter. this one is only 3 inches and is 11 inches long. so it is a little on the small side. all my innercooling pipe will be 2 inch as well as the innercooler in lets and out lets. I choose 52mm throttle bodies so the velocity will remain high. the plan is to run the car off idle to about 6500RPM. I only have a 1/8th mile track here so when i do go to the trace this motor should perform well. see thid is a cruzer and a part time drag car. a toy!!!LOL thid id my first turbo car. so this is a learning experence. so i look forward to your comments and ideas!


You have the right thinking but i also think you are being missled. Let me explain.

2 small t1 turbos might work alright but i dont think they will be happy in the upper rpms. Remember, each one of these turbos will be driven by 1.75L. Thats right about honda territory. I know honda guys would never be caught dead with a turbo that smalll. Why? Because they are reving pretty high and make more power than a NA 2.2 ever made.. so they require a bigger turbo.

Im all for trying twin t1 turbos, even if they are a little bigger than the stock VR4 turbos. Something to remember is that the g72 quickly maxes out the stock VR4 turbos.. and that is a 3.0. You have a 3.5L.


I love your intake and i support the 52mm throttle bodys but i dont support 2inch pipping and small throttle bodys in the name of keeping velocity up. The velocity will be there even with 2.5inch piping and 58mm throttle bodys.


Eds car has bigger intakes and 80mm throttle bodys. We drove that thing for a week straight all across the country. That being said, it was really responsive to throttle tip-in but if he can do it with twin 80s, i think you can handle twin 58mm or even bigger. I think 60mm throttle bodys came on the 3000gt and 4g63 motors. You will make more power in NA form with the bigger throttles and your turbos will spool earlier as an effect.



anyways, i dont think you will see the power you would like to see if you stick with the t1 turbos. 3000gt guys build the 3.5 all the time. You are blessed to be able to follow their footsteps and see what they do to make what power. The car will be a riot either way but i think it will be a torque machine that chokes out in the high rpm if you do stick with the smaller turbos.

homeboysduster
09-05-2012, 08:31 PM
well the goal is a cruzer/part time drag car. I really don't want to go high up in the RPM range. I just want a fun car to drive and the twins are more for show than go!LOL yes they will be good at stop light jumping and also at my 1/8 mile drag strip. I just thinkk it will be a fun car to drive!

Sundance 6g72
09-05-2012, 08:54 PM
my worry is that they might spool to soon

homeboysduster
09-05-2012, 09:04 PM
my worry is that they might spool to soon
it's all good. the turbo's and BOV's were free!!!! and if I don't like them the car will be set up and a turbo upgrade will be a simple swap. no loss but plenty to gain!

c2xejk
09-06-2012, 04:45 PM
i assume the block is getting honed anyways? good looking out on the new rings. Also, if i had to make a guess, this is a 10:1cr engine. low boost or alky injection would be required. That or running race fuel or e85.

I haven't made the measurements yet, but I think we can increase the size of the combustion chamber and drop that compression ratio some... I know the 24v SOHC heads respond REAL well to unshrouding the valves. I suspect the DOHC heads will as well.

homeboysduster
09-06-2012, 05:22 PM
I haven't made the measurements yet, but I think we can increase the size of the combustion chamber and drop that compression ratio some... I know the 24v SOHC heads respond REAL well to unshrouding the valves. I suspect the DOHC heads will as well.
and that Ed is why your getting my heads!!! port polish and combustion chamber mods!

homeboysduster
09-07-2012, 03:03 PM
I am so glad I replaced the rings in this motor!!! cyl #1 and cyl #4 were so carboned up that the top ring was locked into the ring land! it took a bit of work to get the compression rings out without damaging the piston. other than that all is well. I file fit the rings. .035 on top and .032 on the 2nd. now I have a great deal of cleaning to do before assembly!!!
https://sphotos-b.xx.fbcdn.net/hphotos-ash3/s720x720/530177_355993637815365_1867560817_n.jpg

turbovanmanČ
09-07-2012, 04:40 PM
I pulled my pistons today. and as I expected the ring gap was to small!!! only 0.012 inches! new rings it is!!!
https://sphotos-b.xx.fbcdn.net/hphotos-ash3/523097_355306304550765_1110556368_n.jpg

Looks like the head gasket was leaking, :eyebrows:

homeboysduster
09-07-2012, 09:35 PM
Looks like the head gasket was leaking, :eyebrows:

yea, it was!!!LOL that kind-a happend when it lost it's timing belt!!! 20 of the 24 valves were bent!!! pistons survived!!!I was amazed!!!

Shadow24
09-08-2012, 06:59 AM
I bent all the valves in my SOHC 24v and the pistons were barely scratched. Piston > valve stem lol

homeboysduster
09-08-2012, 07:36 AM
I bent all the valves in my SOHC 24v and the pistons were barely scratched. Piston > valve stem lol
LOL!!! yea, I had a couple of valve stems that were shaped like a "Z"!!! had to use a hammer to push them back so i could get them out! now I need to just install the new guides.valves,and seals. then get Ed to port them and I am done with the long block!!!!

Shadow24
09-08-2012, 10:45 AM
Rockauto.com FTW on those parts. I have all new valves ready to go for my 2nd set of heads for cheap.

homeboysduster
09-08-2012, 10:53 AM
Rockauto.com FTW on those parts. I have all new valves ready to go for my 2nd set of heads for cheap.
yea, I got mine too! valves, guides, and seals. as well as a full gasket set. just have to save up for the heads. I will also have Ed port my exhaust housing on the turbos.

c2xejk
09-09-2012, 07:34 AM
Eds car has bigger intakes and 80mm throttle bodys. We drove that thing for a week straight all across the country. That being said, it was really responsive to throttle tip-in but if he can do it with twin 80s, i think you can handle twin 58mm or even bigger. I think 60mm throttle bodys came on the 3000gt and 4g63 motors. You will make more power in NA form with the bigger throttles and your turbos will spool earlier as an effect.

A note on this. For a while I ran twin 58mm TBs and they were MUCH touchier than the twin 80mm TBs w/progressive linkage...

Shadow24
09-09-2012, 10:29 AM
i bet the progressive linkages are what helped. stock 58mm's would have a stock linkage profile so I could see it being touchy.

RoadWarrior222
09-09-2012, 01:34 PM
I'm not seeing how those turbos are too small... yet. I've convinced myself they're a good size in pairs. I'm curious to see where they spool. If boost is coming in at 4000+ on a 3.5 motor, I may rethink using them on a 3.0.

For my sometime in the future N/A twin TB build, I'm just gonna use a pair of 48s I have, those should be "enough" really to hit 300HP or so, and I doubt my build will gain more than a hp going bigger unless I'm close to 300ish. I'm aiming for mid 200s and perfect DDability still.

I have an early motor and late motor, slider cams fatter rings, and roller cams thinner rings. I wanna just port the roller heads for N/A and slap those on at first, and rebuild the later bottom end, possibly stroking it a bit to 3.2. Then the earlier bottom end, which also might be lower compression (though you know how accurate all this stuff is) may get built for turbo duty, since it has beefier ring package. Also I can do some trick sh!t with the slider cam, like fatter followers... then that will be looking for a vehicle to live in.... possibly something that didn't got a 3.0, like a lancer, or something comfy like a dysentry, or maybe a 2nd gen AWD van.

homeboysduster
09-09-2012, 03:37 PM
I may be forced to use a single throttle body. as this motor keeps coming together less and less room become availible. so i may not have to worry about it.

RoadWarrior222
09-09-2012, 04:37 PM
Dr RW prescribes half an hour of tetris every evening before you go to bed... :D

homeboysduster
09-09-2012, 04:54 PM
dr rw prescribes half an hour of tetris every evening before you go to bed... :dlol!!!

Irocelectric93
09-10-2012, 01:15 PM
I may be forced to use a single throttle body. as this motor keeps coming together less and less room become availible. so i may not have to worry about it.Im finding that with my SOHC 3.0 and the route i originally wanted to go with twin plenums. Good thing i picked up a montero lower intake. I think i'm going to end up going with one large plenum with a 80mm TB from a q45. I have two of them already lol....now what to do with my plenums i bought...

RoadWarrior222
09-10-2012, 01:17 PM
spray them black and JB Weld them on top of the hood.... it'll look trick.

Irocelectric93
09-11-2012, 10:36 AM
spray them black and JB Weld them on top of the hood.... it'll look trick.HAHA it'd look awesome. Kinda like those hood scoops that use double sided tape.

homeboysduster
09-28-2012, 03:10 PM
short block assembled and ready to install!!!

https://sphotos-a.xx.fbcdn.net/hphotos-snc6/206357_363231727091556_2029611457_n.jpg

the turbo dodge aluminum fly wheel on a Kia/Mitsubishi 3.5!!!!LOVE IT!!!


https://sphotos-a.xx.fbcdn.net/hphotos-prn1/560487_363231780424884_768416767_n.jpg

RoadWarrior222
09-28-2012, 05:38 PM
Hmmm didn't know you could find them in Kias, will have to look around, there's one or two yards within striking distance that do engine sales.... or all you can carry sales... which would probably mean I'd have to carry it out in two doses (i.e. stagger with the block, then with the heads) but would still be pretty cheap. We didn't get Mitsu mitsus until relatively recently so there's nothing of them to find.

homeboysduster
09-28-2012, 06:22 PM
Hmmm didn't know you could find them in Kias, will have to look around, there's one or two yards within striking distance that do engine sales.... or all you can carry sales... which would probably mean I'd have to carry it out in two doses (i.e. stagger with the block, then with the heads) but would still be pretty cheap. We didn't get Mitsu mitsus until relatively recently so there's nothing of them to find.
I got my 3.5 out of a 02 Kia sadona van! the timing belt snapped and the shop sold it to me for $40! and the cool part is ALL of the mitsubishi 3.0 DOHC and VR4 parts fit perfectly! only need to keep the 3.5 intake due to the block being taller!

homeboysduster
10-01-2012, 01:53 PM
mock up is complete!!! these are the 2 intakes I am thinking about installing!

https://sphotos-b.xx.fbcdn.net/hphotos-ash3/548320_364269790321083_1399604979_n.jpg

https://sphotos-a.xx.fbcdn.net/hphotos-snc7/3133_364269870321075_2118082697_n.jpg

and it looks like a got a lot of room even with the radiator installed!


https://sphotos-a.xx.fbcdn.net/hphotos-ash4/267226_364269933654402_1566589649_n.jpg

https://sphotos-b.xx.fbcdn.net/hphotos-ash4/282096_364269990321063_96455484_n.jpg

https://sphotos-b.xx.fbcdn.net/hphotos-ash4/404592_364270143654381_805596317_n.jpg

https://sphotos-b.xx.fbcdn.net/hphotos-prn1/541113_364270270321035_1871216164_n.jpg

https://sphotos-a.xx.fbcdn.net/hphotos-prn1/546323_364270393654356_1420489496_n.jpg

https://sphotos-b.xx.fbcdn.net/hphotos-ash3/577386_364270526987676_443328774_n.jpg

RoadWarrior222
10-01-2012, 03:13 PM
Looking good, it went straight on the mounts?


the timing belt snapped and the shop sold it to me for $40!Ah yah, that's a point, half the world believe these are interference.

homeboysduster
10-01-2012, 03:54 PM
Looking good, it went straight on the mounts?

Ah yah, that's a point, half the world believe these are interference.
all the mounts matched except for the right hand! that one i need to fab up. and yes it is an interference engine! that is why I got it for so cheap!!!LOL it bent 20 of the 24 valves!!!! but the pistons are fine and the motor now has new rings and bearings! and soon twin turbos!!!

RoadWarrior222
10-01-2012, 04:25 PM
ohhh these ones ARE... guess I was meaning half the world think the 3.0 is when it isn't.

homeboysduster
10-01-2012, 04:42 PM
ohhh these ones ARE... guess I was meaning half the world think the 3.0 is when it isn't.
it isn't a 3.0. it is a 3.5 DOHC! I moved up from the 3.0 same motor just 10mm taller.

RoadWarrior222
10-01-2012, 04:47 PM
yes, got that it was a 3.5, but originally thought it was also non-interference like the 3.0, but a lot of people think the 3.0 is interference anyway...

homeboysduster
10-11-2012, 05:07 PM
working on mods to the intake and throttle body! 70mm TB from old duel intake! the tape is holding the JB weld in place till it drys. I plugged up a few vac ports and the PVC ports in the lower intake. I hope that in the morning I will be able to powder coat them and do the finish assembly on the intake!

https://sphotos-b.xx.fbcdn.net/hphotos-ash3/560415_367958006618928_288630090_n.jpg

https://sphotos-b.xx.fbcdn.net/hphotos-prn1/527311_367958026618926_222188382_n.jpg

Reaper1
10-12-2012, 03:22 PM
Wow! I didn't know all that had happened! Sorry to hear about the bad luck, but it looks like maybe things are working out anyway. I suppose I need to go look at TD and read up on my threads over there! LOL I haven't been on there in months!

Ondonti
10-15-2012, 04:26 AM
Joe, the 2" pipes are because he is running twins. 2" pipe is actually overkill for one of those turbos but easier to use. I stick with larger 2nd ring gaps then top ring gaps to prevent ring flutter. Not sure why you went so big unless you plan on some serious tuning problems. Found that much smaller gaps still achieve piston invulnerability. Did you break the glaze on the cylinders?

BTW the record for a 10:1 4 valve stock shortblock with oem gaps is 140mph in the 1/4. Motors would never hold together for him though. Bent rods or butted rings breaking ringlands.
6g74's have baby rods so those will go before your pistons. Stock for stock a 6g72 can handle a lot more power then a 6g74. Harder to get there of course.

homeboysduster
10-16-2012, 05:48 PM
did some powder coating today!!! I still need to polish the letters but it looks great!!

https://sphotos-b.xx.fbcdn.net/hphotos-snc7/581415_369807339767328_1530428288_n.jpg

RoadWarrior222
10-16-2012, 06:11 PM
Looks grape... umm great.

homeboysduster
12-24-2012, 11:01 AM
Ed sent me an update on the head porting!!! it looks great!!!

http://imageshack.us/a/img856/6227/imag0264xr.jpg

c2xejk
01-03-2013, 01:29 PM
Ok, here is the flow data for Bobby's Kia 6g74 heads as measured on my bench

intake ports

lift stock ported
0.05 47 61
0.10 97 111
0.15 151 163
0.20 191 209
0.25 228 249
0.30 245 276
0.35 247 293
0.40 244 303
0.45 244 309
0.50 236 311


The exhaust ports

stock ported
0.05 41 50
0.10 86 94
0.15 127 134
0.20 155 164
0.25 171 185
0.30 179 191
0.35 182 194
0.40 184 196
0.45 185 197
0.50 185 198

The data graphed
http://img138.imageshack.us/img138/2005/6g74dohcflow.png

Ed Kelly - www.kmperformance.com (http://www.kmperformance.com)

RoadWarrior222
01-03-2013, 02:10 PM
Interesting, would be more interesting to see other solid 6G7x head data to compare to.

Reaper1
01-03-2013, 08:28 PM
Why does the exhaust on almost any 6GXX head seem to suck so bad!? I mean really? Right at 300 for most of the lift range on the intake, but only 200 on the exhaust!? WTF? There HAS to be a way to get these things to exhale!

Ed, I'm not saying you did a bad job by any means. You made very nice improvements across the board....it's the platform on which it started. Ugghh.. (and yes, I still love the 3.0)

What's the point in letting it in if you can't get it out? The cams will have to have some overlap to blow the exhaust out in order to really get this thing going.

Sundance 6g72
01-04-2013, 12:32 AM
^ agreed. I was reading up on a huge high hp build on 3sx. the guys cam of choice had very little overlap.. he switched to something that did have some overlap and ended up going much faster.

im not really a cam guru but it makes sense in my head

RoadWarrior222
01-04-2013, 07:10 AM
But... you only need 2/3 to 3/4 of intake flow on the exhaust side.

---------- Post added at 06:10 AM ---------- Previous post was at 06:04 AM ----------

(and don't forget the valve sizing is skewed that way too, so unless you go +3 on the exhausts or something and leave intakes alone you're not gonna get very near it.)

Sundance 6g72
01-04-2013, 01:42 PM
doh lol

c2xejk
01-04-2013, 01:59 PM
Why does the exhaust on almost any 6GXX head seem to suck so bad!? I mean really? Right at 300 for most of the lift range on the intake, but only 200 on the exhaust!? WTF? There HAS to be a way to get these things to exhale!

Ed, I'm not saying you did a bad job by any means. You made very nice improvements across the board....it's the platform on which it started. Ugghh.. (and yes, I still love the 3.0)

Just about every engine I am familiar with the exhaust side flows worse than the intake. Many try and get exhaust flow to ~75%, but generally the exhaust flow is what it is... You can increase the flow number by enlarging the port exit, but that nearly always will kill hp in the running engine.

The two key reasons that come to mind (Mitsu 12v and 24v) are smaller valve and low port placement. The smaller valve limits the throat area. The exhaust side likes a taller straighter port. The 12v engine is also cursed with a really funky exhaust port design (shape and size.)

I have a chart to post (probably tonight or tomorrow) showing the difference between the 24v DOHC and 12v SOHC heads. I found it eye opening...


What's the point in letting it in if you can't get it out? The cams will have to have some overlap to blow the exhaust out in order to really get this thing going.

Be careful about just looking just at flow numbers, they can lie. Especially on the exhaust side. With the exhaust port we are testing NO where near operating conditions. On the bench temperatures are lower, pressures are lower (especially when the valve first cracks off the seat...)

I don't know that I have ever heard anybody reference more overlap to "blow the exhaust out". Most people are using overlap to pull more intake in...

Ed Kelly - www.kmperformance.com

Reaper1
01-04-2013, 08:07 PM
Just about every engine I am familiar with the exhaust side flows worse than the intake. Many try and get exhaust flow to ~75%, but generally the exhaust flow is what it is... You can increase the flow number by enlarging the port exit, but that nearly always will kill hp in the running engine.

The two key reasons that come to mind (Mitsu 12v and 24v) are smaller valve and low port placement. The smaller valve limits the throat area. The exhaust side likes a taller straighter port. The 12v engine is also cursed with a really funky exhaust port design (shape and size.)

I have a chart to post (probably tonight or tomorrow) showing the difference between the 24v DOHC and 12v SOHC heads. I found it eye opening...



Be careful about just looking just at flow numbers, they can lie. Especially on the exhaust side. With the exhaust port we are testing NO where near operating conditions. On the bench temperatures are lower, pressures are lower (especially when the valve first cracks off the seat...)

I don't know that I have ever heard anybody reference more overlap to "blow the exhaust out". Most people are using overlap to pull more intake in...

Ed Kelly - www.kmperformance.com

I understand your arguments 100%! The density of the gas flowing through the exhaust is WAY less than what is coming in. However, I still believe, especially on a turbo car, that having a much better flowing exhaust would be beneficial.

I also understand we are not taking into account any kind of pulse tuning or anything either.

I think I remember seeing the chart you are talking about, but I'd love to see it again.

Just like dyno's, just because one bench says something, and another says something else, it doesn't mean squat in the real world. I understand that 100%.

Non-N/A engines have the ability to cleanse themselves. If a cam is chosen wisely, the intake charge can "chase out", or cleanse the cylinder. This will yield more power. There are those that will argue that some of your intake charge will go out with the exhaust and you are loosing power. Well, that all depends! LOL The "rebels" I've seen use "hairy" cams in boosted applications almost ALWAYS saw a performance increase if the engine was tuned correctly. Now, that doesn't mean it was more driveable or got better fuel millage...it just made the car go faster.

c2xejk
01-04-2013, 09:44 PM
Interesting, would be more interesting to see other solid 6G7x head data to compare to.

Ok, here is a comparison of the 12v heads to the 24v DOHC heads. On the intake side, the DOHC flows better. However, on the exhaust side, the difference is stark!

http://img15.imageshack.us/img15/5729/dohcvs12v.png

Ed Kelly - www.kmperformance.com (http://www.kmperformance.com)

RoadWarrior222
01-04-2013, 10:05 PM
Awesome :thumb: thanks...

paduster
01-06-2013, 09:55 AM
have u tested your sohc 24v heads yet ed

c2xejk
01-07-2013, 11:19 PM
The cylinder heads are done. They are boxed up and ready to ship out tomorrow.

http://img577.imageshack.us/img577/7168/imag0274yf.jpg

Ed Kelly - www.kmperformance.com (http://www.kmperformance.com)

homeboysduster
01-08-2013, 09:26 AM
YEAH!!!! here comes fun!!!!

c2xejk
01-08-2013, 01:35 PM
have u tested your sohc 24v heads yet ed

I haven't been able to find the data... Once I get my flow bench running again (took it apart to make some changes/fixes) I will get some numbers to add to the chart.

Ed Kelly - www.kmperformance.com

homeboysduster
01-11-2013, 11:29 AM
Well I got my heads in UPS yesterday evening!!! now to start assembling the motor!!! one step closer to twins!!!

RoadWarrior222
01-11-2013, 12:19 PM
Twins! :love::love::love::love:

turbovanmanČ
01-11-2013, 03:46 PM
Nice info, thanks.

Ondonti
01-11-2013, 08:25 PM
I understand your arguments 100%! The density of the gas flowing through the exhaust is WAY less than what is coming in. However, I still believe, especially on a turbo car, that having a much better flowing exhaust would be beneficial.

I also understand we are not taking into account any kind of pulse tuning or anything either.

I think I remember seeing the chart you are talking about, but I'd love to see it again.

Just like dyno's, just because one bench says something, and another says something else, it doesn't mean squat in the real world. I understand that 100%.

Non-N/A engines have the ability to cleanse themselves. If a cam is chosen wisely, the intake charge can "chase out", or cleanse the cylinder. This will yield more power. There are those that will argue that some of your intake charge will go out with the exhaust and you are loosing power. Well, that all depends! LOL The "rebels" I've seen use "hairy" cams in boosted applications almost ALWAYS saw a performance increase if the engine was tuned correctly. Now, that doesn't mean it was more driveable or got better fuel millage...it just made the car go faster.

With proper exhaust side parts a turbo engine will scavenge the same. Backpressure has to be low. I would also say in a half joking manner that if your overlap is too much, I think you are just not reving high enough :P

Reaper1
01-12-2013, 05:24 PM
With proper exhaust side parts a turbo engine will scavenge the same. Backpressure has to be low. I would also say in a half joking manner that if your overlap is too much, I think you are just not reving high enough :P

Agreed, scavenging can work in a turbo application, but unless you've got the pressure ratio down like Shadow does (1:1 or close), it doesn't work well.

I feel kinda dumb, but I can't seem to wrap my head around your revving statement. I know it was written in partial jest, just curious what I'm missing in the intarwebz translation? LOL :thumb:

Vigo
01-13-2013, 12:05 PM
Well if boost level stays the same then the speed that the charge enters the cylinder will stay roughly the same, but as rpm goes up it will have less time to cross the cylinder and go out the exhaust. I dont know if that is what he meant, though.

Ondonti
01-14-2013, 09:06 PM
Well if boost level stays the same then the speed that the charge enters the cylinder will stay roughly the same, but as rpm goes up it will have less time to cross the cylinder and go out the exhaust. I dont know if that is what he meant, though.

Win. This is also why hot cams have smaller power windows when valve duration and lift is not adjustable.