DYNO disaster ? Help

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pilotsf

pilotsf

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Hello again.
You guys are 100 % on all the info you have given me so far ! I have another one.
I just put 10,000 mile on my rebuilt 360e/904t and took it to a dyno and was very bummed when I got the results. I spent 8500.00 on the engine,trans and install(removed blown slant 6). My dyno numbers are 275 hp and 300 lbs Trq. The tester said my Trq was real low and the hp was above average , but my engine is not stock. Can you please tell me how to get the trq up (most important) and then any help about the hp.Or is this a good number? here are my specs

1/4 mile times:13.50-13.70 @ 98-103 mph
Engine
360
bore, 30 over
comp,9-1,9.5-1
cam, 280[at].60 duration 480 lit
air fuel,edelbrock performer rpm manifold and 800cfm edelbrock carb
ignition, orange box mp distributor
headman headers small diameter , and 3 inch strait pipe flowmaster and turn downs

Trans
904
stall ,tci street/strip 1800-2500 breakaway
3.73 gears 28inch tall tire
Please help !!!

l_770a6ecf2a8d4f2eb8162e0cbe5d93a7.jpg
 
When you were on the chassie dyno did they put an exhaust gas sensor in the tail pipe and if so what was it reading eg. lean or rich. Also is that TCI converter a loose unit, eg. a lot of slippage at full load. Are you sure the secondaries on the carb were fully open. What's your timing, initial/total/all in RPM.
 
Also what do you have done to the heads? Remember with an automatic, you loose about 100 HP through the drivetrain so you are more like 375HP at the crank.
 
Chassis dynos, like engine dynos, can be all over the map.

I think that cam is Magnum 280H, 280* at .006 lift and about 230* at .050 480 lift.

What heads are on the engine. Basic stock rebuild with a valve job or cleaned up?

Two things that are hurting IMHO, carb and intake. Rich lean conditions can make a huge difference in power/torque. Did you get a readout showing the A/F's throughout the pulls?

The performer is not the best for getting power. It's basically a stock style 318 manifold in aluminum. The engine would make more power with a holley on it. Seen 20+ hp gains swapping out a correctly tuned ede to a holley.

Like Demonseed mentioned, check the initial timing, get it right, and your all in point. Try to get the all in point in the 2500 area.

A disaster would have been losing the engine during the test, what you have, is the opportunity to get the engine running better. Don't sweat it.:thumblef:
 
I feel with the camshaft you could go a little bigger,what heads,intake?Also with the tall tire,you go a higher gear.My 2 cents
 
I would swap out the intake and carb first. The performer intake has the small runners for a 318. A performer rpm or large runner intake will match up to your ports alot better. And x2 on the edelbrock to holley swap for the carb. And check to make sure your gas pedal is using the full travel of your throttle. I had that issue, Gas pedal was only opening the carb 3/4 of the full travel. Good luck in finding better numbers.
 
On timing, it's probably going to want 15-20 initial and around 35 total. You will likely need to adjust the mechanical advance in your distributor. If it's a newer model MP, it's pretty easy to do.
 
Carb is a little big.
Get an MSD 6a or 6al and MSD coil. Make sure that you are getting good spark. Disconnect the vacuum advance.
Set your total timing to 34 - 36 degrees. Check it with an adj timing light at 5500 rpm. (I use 34 cause the best gas I can get is 91 octane. With 93 I would be more inclined to try 36 advance.)

For the record I had a really similar setup in my Volare and never did better then 14.1 1/4 mile.

Dan...
 
What exactely is done to the motor,and what heads are you running??...
 
Your engine is right inline with your mods....like everyone else says, the "Performer" intake is made for 273/318's. A Edelbrock RPM AirGap is the intake you want.

Theoretically, the edelbrock 800cfm carb is capable, but I would get a Holley 750-3310 vac. secondary, and jet it accordingly to get 13.5-14:1 at cruise/idle, and 11.8-12.5 under WOT.


Then, I would get rid of that Orange Box, and upgrade to a MSD, or Jacobs Electronics Ignition.

13.50 - 13.80 @ 105ish is right inline with 275hp at the wheels in a 3200+ lb car....sorry, its the math...it never lies.

The stuff I just told you would probably yield another 100hp at the wheels properly tuned and extend your rpm range another couple hundred RPM.
 
You say 9 or 9.5 to 1 comp. You don't sound too sure on the compression. Do you know what pistons are in the motor. Anything stock will give you 8 to 1 at most.
It would be nice to know how far in the hole they were when installed.

Also, as said that intake is for a milder or smaller engine.
 
The Carb Is Fine...NEVER Too Big For A Carburetor..All You Ever Have To Do Is TUNE It For Your Engine.I Have A 984 CFM Carb Shop Carb On My Small Blocks.It Has Been On Everything From A 416 To A 318 Stocker.Also Had It On Several Big Blocks.It Has 50 MM Squirters And 50 CC Pumps...

I Would Set The TOTAL Timing At 34-36 At 3500RPM With The Advance Unhooked And The Line To It And The Carb Plugged.The Intake You Have Is A Problem.The Fuel Is PUDDLING In The Plenum.This Is What Happens On And FLAT Manifold If You Were To Put A 2" Spacer On The Intake You Will Get A Lil More Tq And HP.
Next Set Your CL(Center Line)Of The Cam At 104-106o(It Probably Requires 110-112o).This Is Where Your Tq Will Increase Drastically.
Use a "2"HOTTER Spark Plug.I Use Champion,Bosch,NGK Or Autolite Race Platinum Plugs.The Bosch And The NGK Are "9"'s.
The Torque Converter You Are Using Is Waaaay Too Loose For What You Are Wanting To Do.I Use Basically The Same Converter On All My Engines...I Use A 38-4200 That Is TIGHT!....
Put A 999(2.77 Ratio)Low Gear In The Trans And A 4.10-4.56 Rear Gear.I Bet It'll Run 13.00 12.90's with just these Mods.
I Dont Like That Cam Either.Id Put A .484 or .509 In It.


Just MHO And What I Have Experienced...


SS
 
My car turned 290hp on a chassis Dyno and ran an 11.78 @ 118 at the track….. Like you I was all worried about the dyno numbers…. Then I said to myself…… I'm running high 11s something is wrong here but it isn't my car.
 
Those knock off air gaps are nice intakes if you get a new one. And a Bigs carb
 
Good point. I would ditch the dyno and use track times to see improvement. There are alot of good suggestions for you in this thread. Take your time and do it right. Don't try to just throw parts in and expect results. It is all in the combination and intended use. There is a very fine line between having a streetable classic that runs good at the track.
Of course you could drop about 20G into a 6.1 hemi and drivetrain and solve all of your problems.:)

P.S. Prine how have you been doing? Glad to see you are still here. I may be picking up a 5.2 magnum to turbo in my 63 dart. I could sure use your knowledge to make it happen.:)
 
I agree with the intake beign a restriction,there are also better cams but thats in the ball park and should be fine,and as others said cehck/update the ignition.One thing not mentioned but directly relates to your e.t. is your convertor.Any off the shelf convertor is suspect and most are flat out junk,they never stall where they should and most are too tight.At 103 mph Ive ran 12.90s at that speed so theres some losses in your drivetrain.
 
The numbers are dead on with your combo and average machine work. Without disecting I cant see telling you to change anything. So the questions Id look for anwers for are what is the true static compression? Which 280/480 cam and was it degreed? What quality was the valve job? Lastly, what does the car weigh with you in it?
 
1968FormulaS340 said:
My car turned 290hp on a chassis Dyno and ran an 11.78 @ 118 at the track….. Like you I was all worried about the dyno numbers…. Then I said to myself…… I'm running high 11s something is wrong here but it isn't my car.
Click to expand...


Bingo!! Thats why i'll NEVER waiste my $$ on that crap, yeah i said crap lol, all i care about are "time slips", for the most part, they don't lie, i could give a rats azz what HP i have, if it runs the way i feel it should run, who cares, i ran high 10s in my Duster, i couldn't count the # of people who have ask me, how much HP you running, i'd say...."don't know, don't care" lol.
 
demon seed said:
When you were on the chassie dyno did they put an exhaust gas sensor in the tail pipe and if so what was it reading eg. lean or rich. Also is that TCI converter a loose unit, eg. a lot of slippage at full load. Are you sure the secondaries on the carb were fully open. What's your timing, initial/total/all in RPM.
Click to expand...

they put a sensor up by the header . At w.o.t the mixture was 12.20 a bit rich. the tci is pretty solid . carb secondaries , do not know. my timing is 18 at idle and 36 at 3000 rpm.

Thanks for the input
 
hemijoejr said:
Also what do you have done to the heads? Remember with an automatic, you loose about 100 HP through the drivetrain so you are more like 375HP at the crank.
Click to expand...

Thanks for that. The builder told me my motor was 375hp/375trq. the heads are stock 360 heads port and polished only.
 
crackedback said:
Chassis dynos, like engine dynos, can be all over the map.

I think that cam is Magnum 280H, 280* at .006 lift and about 230* at .050 480 lift.

What heads are on the engine. Basic stock rebuild with a valve job or cleaned up?

Two things that are hurting IMHO, carb and intake. Rich lean conditions can make a huge difference in power/torque. Did you get a readout showing the A/F's throughout the pulls?

The performer is not the best for getting power. It's basically a stock style 318 manifold in aluminum. The engine would make more power with a holley on it. Seen 20+ hp gains swapping out a correctly tuned ede to a holley.

Like Demonseed mentioned, check the initial timing, get it right, and your all in point. Try to get the all in point in the 2500 area.

A disaster would have been losing the engine during the test, what you have, is the opportunity to get the engine running better. Don't sweat it.:thumblef:
Click to expand...

Heads are stock, but are built strong and polished. The a/f mixture started out normal to lean and then at w.o.t went to normal to rich at 12.20. I actually have the performer rpm manifold.
Thanks for chillin me out
 
pettybludart said:
I feel with the camshaft you could go a little bigger,what heads,intake?Also with the tall tire,you go a higher gear.My 2 cents
Click to expand...

stock rebuilt heads . the tire gear ratio is for daily driving. I just got so 26 inch slicks for the next bracket drags in sanoma !
Thanks
 
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