340 dyno chart thoughts
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MOPAROFFICIAL
Oogliboogli
Fuel curve and which cam do you have in it?
Can you translate for those of us with old eyes?
stixx
Well-Known Member
I have taken the liberty and cleaned the attachment up a bit for the sake of readibility.
The torque curve looks a bit unusual in that the highest torque seems to be below 3500
and is falling from there.
Was this with the engine out of the car or strapped to a chassis dyno?
The torque curve looks a bit unusual in that the highest torque seems to be below 3500
and is falling from there.
Was this with the engine out of the car or strapped to a chassis dyno?
Odd that the graph starts at 3500.
Considering power drops from there, I'm gonna say, small cam For sure.
I'd like
To know/see the rest of the engine.
Considering power drops from there, I'm gonna say, small cam For sure.
I'd like
To know/see the rest of the engine.
Was on a engine dyno. I'll get the cam specs later. it's a 340. with .030 bore, aluminum heads from performance world which look similar to edelbrock to me.. aluminum ld4b intake that was port matched. 1.5 roller rockers. 600 cfm edelbrock carb. 91 octane fuel and 10 to 1 compression. engine is buit for street only car with power brakes. thanks for the reply it has given me some ideas on questions to ask.
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It does look like it would be a nice performer and have some mileage to it.
roccodart440
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Looks pretty normal to me. I wish he did another pull from a lower RPM.
yellow rose
Overnight Sensation
Post up the rest of the numbers please.
Those two graphs say very little without the rest of the info, other than the cam is too small. I'd bet a pretty good sized jug o whiskey that the numbers show it is severely under carbed.
Headers or exhaust manifolds???
Those two graphs say very little without the rest of the info, other than the cam is too small. I'd bet a pretty good sized jug o whiskey that the numbers show it is severely under carbed.
Headers or exhaust manifolds???
yellow rose
Overnight Sensation
BTW, on a reasonably well tuned A body you are making enough power to go low, low 12's so as far as power it's respectable. My rose colored glasses say you left a bunch on the table with cam and induction. But that's just me.
oliver
Well-Known Member
Well, thats one hell of an undercammed, undercarbed, and under manifolded engine. I'd be willing to wager a c-note that you would pick up 100hp and move the tq up in the rpm range with a decent cam in the block ( 230-240 deg at .050" and low .500's on the lift), a 750cfm carb, and an performer rpm manifold. also i bet you aren't running enough timing either. 340's love timing especially with good heads, correct quench, and a big enough cam that lowers the DCR.
yellow rose
Overnight Sensation
To the OP....any reason you used dyno headers and NOT the headers that fit the car?
I'm telling you a truth when I say I've seen guys that use dyno headers and the car loses .5 in the quarter when they use the headers that fit the car.
In order for the test results to matter, you have to test as close to real world as you can.
Other than the few things mentioned, it looks good. I'm just waiting to see. Rest of the numbers.
I'm telling you a truth when I say I've seen guys that use dyno headers and the car loses .5 in the quarter when they use the headers that fit the car.
In order for the test results to matter, you have to test as close to real world as you can.
Other than the few things mentioned, it looks good. I'm just waiting to see. Rest of the numbers.
He used his header as they have the sensors in them for I believe exhaust temp. timing I belive is set about 37 degrees. cam choice was based on having enough vacuum for my power brakes. thanks for all the comments learning lots
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roccodart440
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What kind of whiskey are we talking about here..? grin
My dyno guy doesn't have a set of TTI's and I wasn't about to put holes in mine or buy another set to use once on a dyno. What I ended up doing is strapping it on a chassis dyno after the break in and initial tune for the final tune.
They were close but like YR said there was some still left on the table.
You guys are funny as hell.
oliver; I can say that as well to any engine.
YR, I'm surprised! So many places cry, I can't fit street car headers on my dyne. (Waaaaaaa!) Use mine instead. Almost standard.
JD, we'll see what the cam is.
oliver; I can say that as well to any engine.
YR, I'm surprised! So many places cry, I can't fit street car headers on my dyne. (Waaaaaaa!) Use mine instead. Almost standard.
JD, we'll see what the cam is.
yellow rose
Overnight Sensation
I have never seen a set of headers not fit a dyno. I would have rather used my headers, but that's me. Either they were monitoring EGT's or A/F ratio. I get it, but what you have on the dyno won't always match what you get in the car.
there was slight change in dyno numbers on the last run he did. keep in mind this is a street engine. built for more drive-ability and for a car with power brakes.it made 10" @ 750 rpm and 14" @ 2600 rpm. im just interested in people thoughts on the set up and how it performed overall and any pointers going forward. also still running break in oil if that makes a difference. timing was last set at 35 degrees. compression is about 10-1 running with 91 octane. i look forward to your guys thoughts on it.
nm9stheham
Well-Known Member
I like the torque being good down as low as it is for pure street use. Wish the numbers were shown down to 2500 RPM; I suspect torque will be solid down there too. I would not worry about the peak HP.... it should be be quick and very responsive as it is.
I'd like to put an AFR on the actual car and see the AFR numbers at mild throttle and cruise.
I'd like to put an AFR on the actual car and see the AFR numbers at mild throttle and cruise.
He told me he doesnt like to do a power run on newly rebuilt engine starting at a lower in the rpm range as he has had issues before like blowing a head gasket. unless of course the customer wants it. i guess its harder on the fresh motor. im no expert so i took his advice. i know everyone is always wanting those big numbers but over all i think its a good motor. sounded awesome
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