[transzex]

the only thing that comes to mind was rulle of thumb 3-4% gain in hp AND tq per full point of compression increase.

9.2 to 13.7 compression.......

I'm at 130 whp, that would put me at 148 whp (dynojet) and ported head should bump me to 155-160 whp, it not more!!!!!!!!

My goal of 145-150 whp D15 is not out of line........

 

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torque wins races, hp wins benchraces

 

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Wanna bet?????

Just have to be VERY careful with the tuning......

 

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According to most of the big name tuners, running much over 12:1 on a street engine has diminishing returns. You have to pull so much timing to run pump gas that you'd make the same power with lower compression.

screw the tuners, talk to the engine builders..........

Have you read who won the lastest Engine Masters build-off?????

http://www.popularhotrodding.com/enginemasters/challenge/2006/0610em_challenge_results_friday/

Wanna guess who's been helping me?????

Next week Tony's moving his shop to St. Leon, IN......needed more room.

 

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I prefer to stay with Honda engine builders and tuners. It amazing who you can talk to on Honda-Tech.

Rage Racing/Whitfield Tuning
Church's Tuning
RLZ Engineering
Rocket Motorsport
Don Flores
etc.

Seriously, hit the All-Motor forum over there and start asking those guys what they think of high compression in anything other than a race engine. They'll all tell you to run less than 12:1 and get a quality port and polish...for a street engine.

and Bisi E. is still the fastest NA SOHC, all those guys are DOHC's....

I have over 6300 posts on HT, been a memeber there for over 5 years, I know how to dig thru the forums there.

 

[transzex]

chamber and piston tops polished to remove hot spots......I'll be running the big Crane cam, maybe later stepping up to a Bisimoto with even more duration.....

Ideally, I'd like to tune for 89 octane to be safe. When started it will have a "safe" chip and race gas. Base Total timing will be 24 BTDC @ 7500 rpm @ WOT and I'll have the dizzy retarded.

I do know it won't take much detonation to hurt the VX rods.....

 

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I've been at this how long?????

Using different OEM pistons to gain compression in a V8, same thing I'm doing now, just about 1/4 the displacement.

 

[transzex]

http://www.bisimoto.com/

BTW, nice read on both those articles, I read the same thing twenty years ago about the time "swirl ports" came into NASCAR. Whether Larry did/didn't have a hand in it, thats between him and Ernie.

Explain why SBC all have the same length trumpets on Hilborn injection systems but the BBC had two different lengths.

The MIT/NACA paper was published in June 1944 or 1945 and the theory is still used today.

 

[transzex]

static vs. dynamic......lets add a bumpstick to mess everything up.....

or do you start with the cam then figure compression?????

LSA between intake and exhaust events, centerline.......blah blah blah.....

Just the surface is being scratched....

Lets see, 740 Dart Iron block, Big Chief heads, 14:1 compression, dual 1150 Dom's, Wilson intake, 3 stages of nitrous for 1000 shot......yep, I'm clueless

6.82 @ 213 only using 2 stages (600 hp) of nitrous in a old Pro Stock chassis (early 90's).....90-92 Trans Am skin.....

just air pumps.....

 

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Why does NASCAR only run 12.5:1 with huge cams and still get 800hp?

Because thats the rules mandated by NASCAR, they used to run 16-17:1 until NASCAR made the rule trying to keep engine costs down.

I feel less intelligent for having even posted on this forum. Flame away, asshats.

Your the jackhole for not knowing the rules. Seems like your at a "Crossroads" in your life, not knowing what you want, but have alot of pent up angry.

Do us a favor.......

 

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The only thing I'm hanging is my dick in your wife's mouth.

Damn, I'm out of the cool kid club.

I'm divorced, she got fat (doubled her weight) so if your getting a BJ from her, hope she swallows because she's likely hungry!

 

[transzex]

we are poor boys, but done correctly the PROPER piston would be dished, not a flat top or domed.

"Dude, you got a HEMI?"

Lets talk quench......

Is it BAD for the piston to KISS the head????
Not if you wanna keep the quench as tight as possible.


Closed chamber vs. open chamber heads.......there is not PERFECT motor....

Porting won't get you above 100% VE, tuning the resonant pressure wave will, aka "Ram Effect".....porting will help this wave though......

 

[transzex]

How do you tune that resonant wave?

Intake runner length. Very possible to get 120% VE.....like Bisi uses on his SOHC D and F motors, carbs at that If you'd done some research you'd found the MIT/NACA papers I talked about, along with the Mopar Max Wedge motors. My stock D15B7 achived over 105% VE with one bolt-on in 1998, I still run that same part today. 119 lb/ft at the crank assuming 15% driveline loss on a Dynojet, not bad for a motor rated at only 98 lb/ft.

You bring Dave @ SMSP into the mix, if he had time he might reply. But he's usually busy building headers. I need to call his cell phone, he's helping me design the header that will work good with my high comp build, but also work with 8-10 psi from the AKSC. Likely I'll have to goto VA with the AKSC so he can build around it.

 

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btw, LFP, you done having fun yet?????

 

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Unshrouding the valve is worth its weight in gold.

But everyone wants bigger valves

Bigger is always better right???

#1 reason I think the VTEC head doesn't work as well as it could, the valves are shrouded by the cylinder bore.

D-series loves 78mm cylinder bore....to unshroud the valves, but for most of us here it is cost prohibitive. So we work with what we (say that fast!) can afford.

 

[transzex]

My point is that you reach a point of diminishing returns by just raising compression.

We know that, have known for years, but we are not building $30,000 race motors that make 850 hp.

 

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Unintelligent people seldom care about being educated.

LFP, why you avoid the questions?????

 

[transzex]

Your graph says I only need 150 cfm for 40 hp per cylinder @ 7000 rpm, so what do I do with 220 @ .425" lift????

 

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The problem is that nobody's done anything more than flame me. Nobody's been able to prove that you can run 13:1+ with 28-32 total timing on 93 octane. Nobody's proven me wrong that lower compression and a properly ported head will always be more efficient. The fact is that nobody here cares about building engines correctly. In that respect, I guess I am beaten but I will not conceed a more than valid point to the ignorant masses.

Who said anything about running 28-32 total on pump with 13:1+ compression???? That bitch would be knocking like crazy. I'll be lucky to get 24 total, 26 total if I say a prayer!

 

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Weekend warrior/road race without juice. About the only things I really have left to figure out are what cams and valve train. I need to do a lot more research on the B-Series to find the cams that will give me what I'm looking for which is a lot of mid-range. My head porter's input will be greatly influencial in my final decision.

try the AKMEE cams, heard they hot!!!!!