347 dyno numbers are in! (finally)

[85_SS_302_Coupe]

Well, stopped by my local speed shop today www.CincySpeed.com - Home and managed to sweet talk my way into getting squeezed in for some spur of the moment dyno time. To make a long story short, it was filthy rich and total timing was 42 degrees when i drove it in (and amazingly enough it didn't ping)! They took great care of me, jetting it down/up where needed, dropped total timing down to 35 and ripped the rollers. Here's what i got:

Not bad for 40 year old heads huh? I'm probably at the stage where i could start to use a nice single plane intake and possibly even a 700cfm carb. It runs stout as hell now


Overall i'm pretty damn happy with the numbers considering how much more i can do to it. I can go single plane intake, bigger carb, recurve the distributor, obviously get better heads...all that should put me a good bit past 400rwhp.

 

[iapexl8r]

very well done!!! kudos to you those Numbers are excelent!!! what heads?

 

[85_SS_302_Coupe]

very well done!!! kudos to you those Numbers are excelent!!! what heads?

Ported/polished '69 C90E 351W, 1.94/1.60 valves (say that 3 times fast).

The engine is a 347, about 9.25:1 compression, AFM N-91 cam, Stealth intake, Holley 650dp, plus all the other typical bolt-ons. I'm tickled to death because my buddy's 347 only has me by about 20hp and 30tq, and i still have room to grow.

 

[bentley429]

Damn nice numbers for stocker heads and low compression. Whats the exhaust?

 

[cenok is family]

damn dude! congrats on the numbers! i'd be STOKED with that kind of power! lets see some vids of you rippin it now!

 

[skunk21]

nice #'s,

 

[85_SS_302_Coupe]

Damn nice numbers for stocker heads and low compression. Whats the exhaust?

1 5/8 Mac full lengths, Dr. Gas offroad X, Magnaflow cat-back with tails, all 2.5 inch. I really wanted to get video of the pulls but it was so last minute that i didn't bring the camera. I didn't even expect to get in, i just figured it never hurts to ask and they got me right in.

Hey if you believe the whole 15% drivetrain loss thing, that puts me at 416hp/418tq. They also said it's typical for drag radials and slicks to rob you of a few ponys.

 

[bubba-dough]

Good #'s....Its always nice to see proof of things, like dyno charts, pics & vids, takes the guess work out of who lies

 

[85_SS_302_Coupe]

Good #'s....Its always nice to see proof of things, like dyno charts, pics & vids, takes the guess work out of who lies

I got a crappy cell phone pic...that's about all i could pull off

Don't laugh at my multicolored whip

 

[bubba-dough]

Don't laugh at my multicolored whip

lol, but paint don't make a car go fast...I know in another thread you were talking about having to hold off on paint because of the engine...but out of curiousity what color/paint scheme are you gonna go for?

 

[85_SS_302_Coupe]

lol, but paint don't make a car go fast...I know in another thread you were talking about having to hold off on paint because of the engine...but out of curiousity what color/paint scheme are you gonna go for?

Well like everything else that's probably gonna come down to cost. My buddy has a gallon of PPG paint that's almost exactly Grabber Blue. Seeing as how that's FREE, it'll probably get that with a satin black hood/scoop and satin black window trim and sail panel. I'd like to do it in Buick GNX black with the satin accents...we'll see. For now i'm totally content with doing body work and having the power as opposed to having the looks and no power.

All go/no show > all show/no go

 

[1991notchbackLX]

those are some damn good dyno #'s for 40 year old heads, your car is just badass

 

[85_SS_302_Coupe]

Thanks everyone...feels like the old dog is finally getting her day


I'll still say it's a waste of time to put a ton of money into porting stock heads. I know guys are making great numbers with Thumpers, and obviously they're working good for me here...but i also have $710 into my heads after putting new valves in them, and that's considering that i bought them with the port work already done. With the numbers i'm making i have to believe the heads are much better ported than i expected, and that kind of port work costs $$$$. For $700-800, you can score used aluminum aftermarket heads and get better flow, better port velocity, and you'll drop a good 75lbs to boot. All that aside, if you ever come across some heads that are already ported and they're for a good price...this shows that ported stockers CAN make decent power.

 

[bubba-dough]

Is Cincy Speed Shop kind of close to an old distillery of some kind? Right off the Interstate/hwy? Its been a few years but when I picked up the hood for my dd....which btw is a whole other story/adventure we had to kill some time and those guys didn't mind us one bit window shopping/killing a few minutes talking it up until the guy at the hood place met up with us.

 

[85_SS_302_Coupe]

Is Cincy Speed Shop kind of close to an old distillery of some kind? Right off the Interstate/hwy? Its been a few years but when I picked up the hood for my dd....which btw is a whole other story/adventure we had to kill some time and those guys didn't mind us one bit window shopping/killing a few minutes talking it up until the guy at the hood place met up with us.

Yep right off I75, maybe 1/2 mile or so. The side of the building is black/white checkered like a checkered flag.

 

[SMOKEDYA]

this is a 347 with ported 69 351 heads?

 

[85_SS_302_Coupe]

this is a 347 with ported 69 351 heads?

Umm...yes...is it good or bad?

 

[SMOKEDYA]

**** man i dont know? all i know is i hope my AFR headed 351w 40 over makes that if not more?

 

[85_SS_302_Coupe]

**** man i dont know? all i know is i hope my AFR headed 351w 40 over makes that if not more?

Oh...yeah i know what you mean. I went in just crossing my fingers that it would at least make 300/320. Before the stroker i had another dyno day scheduled for the stock shortblock combo and i was hoping and praying it would make at least 250 at the wheels...it's kinda hard to believe it's 100 over what i had hoped for back then.

I don't really know what to expect out of a 351. I get mixed opinions on whether or not a stroker is equal to or better than a 351 as far as power output. Some people say the stroker crank makes the difference, and they go into rod to stroke ratios and stuff i don't really understand.

Then again, my heads are pretty seriously ported...i'm starting to believe the story about them coming off of a dirt track car. When i got them, they each had a bent exhaust valve and when i took them to the machine shop i asked the guy to give me an honest opinion of the port work and tell me if it's even worth messing with them, and he said he hadn't seen hand port work like that in years.

Here's a few pics of them for anyone who's curious.

I really think a lot of it has to do with the cam too. The guy doing the tuning said it's one of his favorite off the shelf cams.

 

[cenok is family]

hell yeah afm cams are badass! I love mine!