Disappointment at the dyno: 227 rwhp with afr165's and custom cam

[crazypete]

So yesterday morning, I went to the dyno for my first ever "official" run of the car on a dyno to see what all my years of hard work and toil and money have achieved.

I had read that carcraft article about running afr165's and a stock cam with nothing but 1.7 roller rockers, a dual plane intake, a 625 carb and some longtubes.

http://www.carcraft.com/techarticles/116_0307_ford_302_v8_engine_buildup/

They pulled 400 hp out of the motor....about 320 to the rear wheels, lets say with 20% drivetrain loss.

I rolled in expecting to see 280-330 RWHP because I have a custom cam, edelbrock performer, afr 165's 1.7 cobra rockers, mac longtubes, I expected to get within at least 20 hp of the article's figures...I had a comparable if not almost identical setup.

Timing was about 12 degrees, mixture was right on via AF guage, two green bars at cruise and 1 orange at hard throttle. Car didnt ping once during all the runs. It even gave a nice puff of black smoke during the runs.

amnit: Look at those numbers..... barely 227 hp to the wheels and 308 torque on the best run. This is sad.crapola

So, needless to say....if I'm getting 11 mpg combined down from my pre-messing with engine 19-20 mpg combined (25 highway), I'm rolling this thing back to stock engine components and tossing some stuff up for sale. 30 measly hp is not worth a 9 mpg drop.

I shoulda done better than that. Ignition was strong and perfectly set up. Carb was set up with a damn good mixture in all situations after weeks of street tuning with an AF guage. It was a rainy day, but that would only clap 10 hp on the ass at most. Compression was tested last year at 165 psi +/- 5 psi on all cylinders, but I did see a little plume of faint white smoke coming from the valve cover during the run so there was some blowby....hell its a 146k bottom end. But still.....

What happened? Any ideas guys? Do I need to punt the cam? Maybe I need to add some more grease... =P

 

[eagleautosports]

Car Craft is operated by non driving idiots. They also put their engines in an enclosed climate controlled room to get numbers. I would say with your combo, it isn't too far from being right but it could be affected by humidity, barometer, and even the type dyno you used. Don't go on just what number it puts up, how does the car feel? AFR heads can work magic but not THAT much that they're claiming. In other words, crapola

 

[crazypete]

I guess the dynojet dyno confirmed what my sotp dyno told me....

A real hard launcher, pulls like a locomotive all the way from idle to 4k then doesnt pull any more afterward. I'm not saying it's slow, but it's low end performance is the same as it's high end performance.

Now I had asked Ed curtis to grind me a street torquer cam that did all of it's magic between 1500 and 4000 and not optimze too much for the top end since it never gets up there. I guess he did what I asked

Might have shot myself in the foot.

I dont remember the number but the insane lift was like a millimeter away from binding the 130 pounder springs with 1.7 corba rockers.

 

[Grn92LX]

Why aren't you running any timing in the motor?

I can think of 3 possibilities for the bad numbers and jagged lines: Need proper valve springs, wrong pushrod length or bad a/f.

You also have an automatic which won't show as "big" numbers.

 

[crazypete]

Why aren't you running any timing in the motor?

I can think of 3 possibilities for the bad numbers and jagged lines: Need proper valve springs, wrong pushrod length or bad a/f.

You also have an automatic which won't show as "big" numbers.

Ok, of those 3....

1. Valve springs. Check. Brand new pieces, triples, sold to me by ed curtis for my cam specifically and check by machine shop.
2. Pushrod length....ed curtis told me factory pushrods were the order of the day for that cam, those springs and cobra 1.7 rr's
3. Bad A/F....this can be argued. It was a rainy day. But it didnt lean ping/backfire at any time driving over or making 4 full throttle runs. It let out a puff of black smoke so it was a bit rich but not enough to make an impact on my A/F guage.

The timing...it used to ping under hard load at 16, so I had to drop back to 12 to run my 87 octane. It didnt want to run rocket fuel, I wanted the hp in street trim.

The automatic....I think 20% loss is good enough estimate...isnt it? AOD with 3k lockup tci streetfighter and a transgo kit. Even if we say 25% loss, I should still get more than I am seeing.

I've seen ppl claim these numbers with a stock cam and exhaust and some gt-40's.

 

[90bluegt]

I would say, put the timing at 14* and put 93 in the gas tank. That would be street trim not 87.
I run 87 in my explorer and 93 in my car.

Just looking up your heads and do you have the part number that you used because according to their (AFR's) website that certain pushrods are required for certain AFR165 heads. Also, what's the cam profile and compression ratio, because the person who gave me my cam (since I was building a turbo motor) told me that until I put the power adder on the motor will be a wicked dog.

 

[Dark Knight]

Your timing is killing HP.. I run 17* on my carbed car with the stock cam and 1.7's... I can run it on 89 octane when it's cool, but it needs 91 in the summer. I have the same combo, but with the stock cam. Mine makes HP to 6000rpm. Port match the intake or switch to a stealth.
http://members.cox.net/darkknight302/dyn012-1s.jpg
You made more torque, but you sacrificed HP.

 

[crazypete]

Gotta run 87....never gonna run anything other than 87. If my car doesnt do 87, then I'll change something to make it take 87. It's my daily driver (yeah, I know....10 mpg daily driver) so it's my left nutt as it is to get to work and paying an extra 30 cents per gallon isnt my thing.

I guess I can bump the timing to 16 degrees. Or I can reinstall my old distributor that had busted advance springs and had 10 total advance, allowing me to run something like 30 degrees intial/40 total .....

But still, is 4 degrees timing worth like 30-40 hp?

The AFR165's are 1472 street legal pedestal mount 60 cc heads. Ed curtis/FTI told me to use the stock pushrods and since he's highly recommended, I'll take it he knows what he's doing.

Hey, doesnt it look like the torque is already on the way down at 3.5k when the chart starts..... maybe my peak torque is higher or off the chart...is that how dynos work? Does it record an earlier peak?

I mean if it made 400 ft/lbs of torque and 225 hp, I wouldnt be all that mad at all. But it's making neither hp or torque....

 

[DMAN302]

Something is definately amiss...I would want to even go so far as to see if you'r running one cylinder down. IMO you short 50HP....and it's there somewhere, you just have to find it.

 

[90bluegt]

That's going to be an issue, with typical dyno results in Mags and such, they usually run at least 93.
The timing should be at 14* at a minimum.
You also have pedestal mount rockers, roller rockers are usually good for another 5-10 horse if not more, they (the mag you refered to) were using adj. pedestall mounted roller rockers.

This wouldn't add up to what is missing they were also using a dual-plane intake as well. If i remember correctly that would also help produce more higher end HP. Also, what are the specs of your cam. I would think that is the main cause.

 

[Boss 351]

you have a 3000rpm torque lockup and an engine that pulls hard from 1000 to 4000 rpm (like a truck engine or something you'd build for a heavy car)? Doesn't look like matched components? What's your gear? But then again I could be wrong...

didn't the article use a stock cam on that 302? and it was on an engine dyno with perfect conditions too... I'd say go to the track

 

[smittyb]

I'd say you are down about 50 hp as well. I agree with a lot of points that have been made. It looks like you definately have a valvetrain problem. There is no way anyone can tell you that the stock p-rods will work for your car unless they had access to your longblock assembly. Yeah, yeah, I know, he's the great Ed Curtis, if he says it... sorry, but you need to determine proper pushrod length.
Also you said "I dont remember the number but the insane lift was like a millimeter away from binding the 130 pounder springs with 1.7 corba rockers." This is a bad thing. You need more clearance than this.

I also agree with Boss, your 3k stall TC is probably not optimum. But, this is the reason your torque curve looks the way it does. You said it dosen't feel like it is making power above 4k, but the dyno shows no great drop. It is probably also due to the TC. Did you have this converter before you had the cam ground, and did he ask for the stall?

One last thing, people are probably going to get pissed, but without knowing your CR, static compression, and cam timing, people are only guessing when they tell you how much timing you SHOULD be running. Just try adjusting it as much as you can without getting into detonation for whatever gas you want to run.

Oh, and I am no expert, just my thoughts.

 

[crazypete]

you have a 3000rpm torque lockup and an engine that pulls hard from 1000 to 4000 rpm (like a truck engine or something you'd build for a heavy car)? Doesn't look like matched components? What's your gear? But then again I could be wrong...

didn't the article use a stock cam on that 302? and it was on an engine dyno with perfect conditions too... I'd say go to the track

Yeah, I wanted a car that pulled hard from the getgo so I felt the power every moment I was driving. I wanted it to explode out of every traffic light and do highway passing and zoom to highway speed effortlessly. I didnt want to be spinning up the motor past 4k to get my power.

So I guess it's what I ended up getting.

 

[tmoss]

oops - gear and a stall converter make it leave hard - then the engine combo carries you.

Is this the exact drivetrain combo that the cam was cut for? Did you change any of it?

timing and tune are very important.............but...........Proper valve train parts selection and SETUP are critical. How good a job did you do?

 

[crazypete]

I'd say you are down about 50 hp as well. I agree with a lot of points that have been made..... but you need to determine proper pushrod length.

Well, lets say that the pushrods were too short... If they were "too long", I would have bound the springs. If they were too short....well, the lift was some crazy high number that required 130 pounder triple springs and would have reached coil bind with 1.72 but not with 1.70's. With that much lift, even if it was less than optimum...It still would have been plenty and plent more than with stock.

I also agree with Boss, your 3k stall TC is probably not optimum. But, this is the reason your torque curve looks the way it does. You said it dosen't feel like it is making power above 4k, but the dyno shows no great drop. It is probably also due to the TC. Did you have this converter before you had the cam ground, and did he ask for the stall?

Yes, I said tci streetfighter and filled out a huge form listing everything I had. BUT...I had 4.56's on at the time of the grind and now I run 3.73's (to save my transmission)....AND...it's not a 3k stall. It's a tci streetfighter which is SUPPOSED to get "like 3k stall", so hell, I could be getting something completely different now that I think of it. I'll do a pedal mash when I get home to see where the flash stall happens. I think I've seen it at 2500 or so at 2/3 throttle blips before. I have to go look.

Either way, it will lockup in 3rd any way you look at it, shouldnt it? It shouldnt affect power curves past it's lockup point should it?

 

[crazypete]

oops - gear and a stall converter make it leave hard - then the engine combo carries you.

Is this the exact drivetrain combo that the cam was cut for? Did you change any of it?

timing and tune are very important.............but...........Proper valve train parts selection and SETUP are critical. How good a job did you do?

I changed gears from 4.56 to 3.73 since the grind.

The valvetrain parts are....fresh heads and valves and springs, fresh cam with proper breakin, old lifters and old pushrods (they were all straight when roll tested), used 1.7 cobra pedestal roller rockers set to 25 ft-lbs with torque wrench at closed position. retightened after 10 minute warmup.

 

[6SpeedLX]

Gotta run 87....never gonna run anything other than 87. If my car doesnt do 87, then I'll change something to make it take 87. It's my daily driver (yeah, I know....10 mpg daily driver) so it's my left nutt as it is to get to work and paying an extra 30 cents per gallon isnt my thing.

in all reality 93 octane actually burns slower from what ive been told, so switching to it and driving easy on the throttle would probably get you some half decent MPG's. if the car is tuned right it should idle and drive like stock. Plus those nice AFR's would appreciate the lovin' your showing them with the good stuff. dont you like to get spoiled?.....i bet your AFR's do




get the timing situation worked out and take her for another pull.

 

[5spd GT]

Is the valve lash set correctly? All rockers are tightened on the base circle of the cam?

 

[crazypete]

in all reality 93 octane actually burns slower from what ive been told, so switching to it and driving easy on the throttle would probably get you some half decent MPG's.

wouldnt that cause slow burning fuel to be ejected out the exhaust port rather than usefully burned in the combustion chamber? I was always told to run the lowest octane I can get away with.

The rockers were set on the base circle of the cam.

 

[Flavadave4]

I am not sure what to tell you about your problems other than what has been said, but i cant believe you would spend good money on heads and a custom cam on your daily driver....... yet wont pay a little more to run 93 octane and some more timing.