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Finally had the 81 dyno'd. Made sure the guy understood I could not be disappointed with the results as I was very content with how the car drives. Just want to calibrate the feel on my backside:
Max hp at tires is 220 @ 4300 rpm
torque is 320 lb-ft @ @2250 rpm
No dispute from the race shop that the engine was a 383 stroker and running strong. He guessed that the engine would producing 350-375 hp.
The racing shop also found that the carb was set too lean, probably for fuel economy. I had him optimize the carb for power so the engine wouldn't run hot on the track.
From: Arizona - If you don’t know CFI, STOP proliferating the myths around it...
Can you post the dyno pull graph? I'd love to see it. Even if you add 100hp to the wheels number for drive-line loss, that puts you less than 350 at the motor. Are you sure it's a 383 build? That sounds more like a good running 355 than a 383. BTW... I like that color blue, looks good.
Last edited by Buccaneer; Apr 14, 2017 at 02:57 PM.
Can you post the dyno pull graph? I'd love to see it. Even if you add 100hp to the wheels number for drive-line loss, that puts you less than 350 at the motor. Are you sure it's a 383 build? That sounds more like a good running 355 than a 383. BTW... I like that color blue, looks good.
I was waiting for someone to ask... :-)
Here is a pic of the graph, kinda faint sorry. Also the pdf scan of the complete final of 15 run test results. I won't pretend to understand anything but the bottom line....
From: Arizona - If you don’t know CFI, STOP proliferating the myths around it...
OK, that is rather faint and hard to see what's going on, but I opened your PDF, why only 4,600 vs. 5,800/6K? I'm having to assume you were WOT at 2,200 and running 12.6ish AFR which would be fine if WOT. I don't know what L1/L2 is for sure unless you were running dual WB sensors or sniffing both sides. If that's the case L2 bank is running leaner. Do you know when your timing is ALL in...rpm wise? Also, something isn't right. You are not making any real power after 3,369rpm for almost 1,000rpm, this is NOT typical of a 383 unless the cam is really small. You should be making power all the way up to around 5,800 or so before it levels off with a nice cam in there. Thanks for posting sheets.
Last edited by Buccaneer; Apr 14, 2017 at 06:27 PM.
Way over my head! Speak English... :-)
All I can tell ya is the car got enough get up and go to put a smile on my face.... maybe do a few burn outs... ;-)
From: Arizona - If you don’t know CFI, STOP proliferating the myths around it...
Originally Posted by PeterC3
Way over my head! Speak English... :-)
All I can tell ya is the car got enough get up and go to put a smile on my face.... maybe do a few burn outs... ;-)
Sorry, I want to look at your sheets some more. Like I said, something isn't right. If it puts a smile on your face now, you will be scared S******* when it's running right. It's all in the tune once the combination of parts are corret. My 383 pulls real hard on the bottom and gives me a very slight case of vertigo for an instant when I launch it hard with DRs. Yours should pull hard as well with a good cam.
Last edited by Buccaneer; Apr 14, 2017 at 06:35 PM.
I should say that the previous owner had the car's doggy drive train upgraded 20 years ago. He specifically told the custom shop that he did not want a kick *** fire breather, just a daily driver with more umfff than stock...
A week ago I was on the track and my engine blowed up - real good.
At first my mechanic buddies and I suspected oil starvation after sharp corners, but after a preliminary look at the engine the cause may have been mechanical failure. But the point of this update is the carb gasket - whats wrong with this picture?
I understand......Never, Ever buy cars from friends or relatives. Doing business with either is a hornets best you are about to lay on.
Good luck
MANY Years ago in the 70's I sold a car to a college buddy and one to a cousin.
Both beat the **** out of them and then expected me to pay for fixing the transmission they blew 3-6 months later.
The family member I split it with him.
The friend....naw....I knew how he drove.
No good deed goes unpunished sometimes...
And if nothing else they expect lifetime maintenance and troubleshooting.....:***** :
Well the PO was not a friend or a relative, but you take a chance regardless. The engine was built by a custom shop and the 700R4 was beefed up by another shop. The engine was lacking in build quality, the tranny is out for inspection. I'm holding my breath on the 700R4.
From: Arizona - If you don’t know CFI, STOP proliferating the myths around it...
Originally Posted by PeterC3
A week ago I was on the track and my engine blowed up - real good.
At first my mechanic buddies and I suspected oil starvation after sharp corners, but after a preliminary look at the engine the cause may have been mechanical failure. But the point of this update is the carb gasket - whats wrong with this picture?
That is messed up whoever did that. I bet after you fix the mechanical issue and install the correct gasket, I bet you pull a few more ponies out of it. Were the secondaries even opening?
Last edited by Buccaneer; Apr 29, 2017 at 03:49 AM.
Looks like you found your problem with the engine output...220 RWHP for a 355/383 was very low. Here is my totally stock 1978 L-82 with no emissions, dual 2.5 exhaust, and shorty headers and a weak compression #6 cylinder (very low):
233 RWHP @5,200 RPM and 269 RWTQ @3,500 RPM. BTW which translate into about 310 Gross HP, no where near the 350-375 Gross HP claimed by the Dyno operator for the OP with 220 RWHP
Last edited by jb78L-82; Apr 29, 2017 at 09:59 AM.
My 383 pulls real hard on the bottom and gives me a very slight case of vertigo for an instant when I launch it hard with DRs. Yours should pull hard as well with a good cam.
