496 falling flat - Page 2 - Chevelle Tech
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post #16 of 49 (permalink) Old Nov 8th, 18, 11:13 PM Thread Starter
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Jeremy
 
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Location: Urbandale, IA
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Re: 496 falling flat

Quote:
Originally Posted by BillK View Post
Jeremy,
Just for a quick check bump the timing up 5 or 6 degrees with what you have and take it for a spin. See what it does. Just dont stay in it if it starts to ping.

That will at least tell you if timing might be the issue.
i have done that and it does ping alot. and doesn't like to start easy.

69 Camaro SS Clone fully restored
496, Straub cam, 700R4, 3200 stall, Fitech Meanstreet EFI with Ahhhh... A/C,
3.42 12 bolt posi rear end
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post #17 of 49 (permalink) Old Nov 8th, 18, 11:31 PM
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Ron
 
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Re: 496 falling flat

Quote:
Originally Posted by 1bad69 View Post
no. not yet. I know I'm not getting all of the performance i can get out of it, so i want to get it running correctly before I do that, or do an LS swap. But I would like to get the potential out of it if i could before I do a swap. I get 14-16 mpg on the highway now. I am liking that!
You have been wanting to do the LS swap for along time if I remember correctly.

69 Camaro
491/AFR 315/Straub hyd roller/pump 91
TH400/GV OD/9" 3.50's/ 255/60/15 DR

10.86 at 124.8
3670 with driver
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post #18 of 49 (permalink) Old Nov 8th, 18, 11:38 PM Thread Starter
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Jeremy
 
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Re: 496 falling flat

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Originally Posted by dirtlips408 View Post
You have been wanting to do the LS swap for along time if I remember correctly.
Yeah.. but if i could get this one to run right... it already gets decent mileage now.. so if i could get it to fry the tires when i stab it i'd be good i think... I like the looks of my motor so much better than an LS... i know there are tricks you can do to make them look better, but you still have the ugly accessory drive on the frt.
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69 Camaro SS Clone fully restored
496, Straub cam, 700R4, 3200 stall, Fitech Meanstreet EFI with Ahhhh... A/C,
3.42 12 bolt posi rear end
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post #19 of 49 (permalink) Old Nov 9th, 18, 12:00 AM
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Gary
 
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Re: 496 falling flat

that thing should absolutely annihilate the tires. i have an 8 to one hyd flat tappet 454 with 331s that will fry the tires at will and you should have a bunch more torque than i do so something is amiss. sounds like ign timing is close based on what youve said. did you degree the camshaft? definitely check the valve springs.are you getting full throttle? a restrictive or clogged exhaust will cause your symptoms.
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post #20 of 49 (permalink) Old Nov 9th, 18, 12:13 AM
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Ron
 
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Re: 496 falling flat

Quote:
Originally Posted by 1bad69 View Post
Yeah.. but if i could get this one to run right... it already gets decent mileage now.. so if i could get it to fry the tires when i stab it i'd be good i think... I like the looks of my motor so much better than an LS... i know there are tricks you can do to make them look better, but you still have the ugly accessory drive on the frt.

Take the car to a good tuner and see what he comes up with on any issues.
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69 Camaro
491/AFR 315/Straub hyd roller/pump 91
TH400/GV OD/9" 3.50's/ 255/60/15 DR

10.86 at 124.8
3670 with driver
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post #21 of 49 (permalink) Old Nov 9th, 18, 12:17 AM
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Ron
 
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Re: 496 falling flat

Is the converter a lock up or non lock up?? How is lock up controlled?

69 Camaro
491/AFR 315/Straub hyd roller/pump 91
TH400/GV OD/9" 3.50's/ 255/60/15 DR

10.86 at 124.8
3670 with driver
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post #22 of 49 (permalink) Old Nov 9th, 18, 1:04 AM
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Kerry
 
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Re: 496 falling flat

Verify true tdc with a piston stop
Then install a timing tape on the balancer and use a old non dial back timing light to check timing.
Then put the exact proper valve springs on the heads for the cam, set to the exact install height for the right seat pressure.
Have you adjusted the tv cable properly? This is very critical to have the trans shift properly and also not slip the clutches.
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post #23 of 49 (permalink) Old Nov 9th, 18, 1:16 AM Thread Starter
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Jeremy
 
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Re: 496 falling flat

Quote:
Originally Posted by dirtlips408 View Post
Is the converter a lock up or non lock up?? How is lock up controlled?
It is a lock up. It is controlled by the tv cable. It doesn't lock up when you are in the throttle. Just when you get the rpms down.

69 Camaro SS Clone fully restored
496, Straub cam, 700R4, 3200 stall, Fitech Meanstreet EFI with Ahhhh... A/C,
3.42 12 bolt posi rear end
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post #24 of 49 (permalink) Old Nov 9th, 18, 1:59 AM
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Chris
 
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Re: 496 falling flat

I wonder if you are getting the very common lean spike/rich bog condition with your FiTech. Could you post a log file of whats happening?

1971 Chevelle SS454, T56 Magnum 6 speed, 3.31 Posi

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post #25 of 49 (permalink) Old Nov 9th, 18, 1:59 AM
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Ron
 
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Re: 496 falling flat

Quote:
Originally Posted by 1bad69 View Post
It is a lock up. It is controlled by the tv cable. It doesn't lock up when you are in the throttle. Just when you get the rpms down.

Oh ok...my dad runs a similar set up to your car....700r4 with 3.42's. He has his lock up switch on the dash and only locks it up on the freeway. Around town and anywhere else but freeway its just annoying when it goes in and out of lock up. Makes the car feel like a dog as well if it locks up in the lower gears.

69 Camaro
491/AFR 315/Straub hyd roller/pump 91
TH400/GV OD/9" 3.50's/ 255/60/15 DR

10.86 at 124.8
3670 with driver
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post #26 of 49 (permalink) Old Nov 9th, 18, 3:24 AM
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Geoff
 
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Re: 496 falling flat

Although it probably won't fix your problem, a Performer RPM would be a much BETTER intake for an engine that is done by 5500 rpm. More responsive, better mileage, broader tq curve.

If it won't fry the tyres as you outlined, it suggests a lot missing low speed tq. Could the cam have been installed on a retarded ICL? My mistake or purposely?
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post #27 of 49 (permalink) Old Nov 9th, 18, 6:53 AM Thread Starter
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Jeremy
 
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Re: 496 falling flat

Quote:
Originally Posted by -SS454- View Post
I wonder if you are getting the very common lean spike/rich bog condition with your FiTech. Could you post a log file of whats happening?
Not sure how to do that? If i can figure it out...i sure will. It did it when I had the carb and mechanical pump also... never did run right with that setup either.

69 Camaro SS Clone fully restored
496, Straub cam, 700R4, 3200 stall, Fitech Meanstreet EFI with Ahhhh... A/C,
3.42 12 bolt posi rear end
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post #28 of 49 (permalink) Old Nov 9th, 18, 6:58 AM Thread Starter
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Jeremy
 
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Re: 496 falling flat

Quote:
Originally Posted by Gtogeoff View Post
Although it probably won't fix your problem, a Performer RPM would be a much BETTER intake for an engine that is done by 5500 rpm. More responsive, better mileage, broader tq curve.

If it won't fry the tyres as you outlined, it suggests a lot missing low speed tq. Could the cam have been installed on a retarded ICL? My mistake or purposely?
I did not degree it. I did run it straight up. It starts good and idles good. Sounds good. I have never degreed a cam and this is a Straub Industries cam, I would hope it would be closer to true than the avg cam. But i suppose it could be off. Depending on the cam grinder.

69 Camaro SS Clone fully restored
496, Straub cam, 700R4, 3200 stall, Fitech Meanstreet EFI with Ahhhh... A/C,
3.42 12 bolt posi rear end
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post #29 of 49 (permalink) Old Nov 9th, 18, 7:16 AM
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jeff
 
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Re: 496 falling flat

No pinging on 91 or 93.
I had a vehicle I was trying to make run right and heard no pinging from it either 427" SBC..I tried all different timing curves.
Different carbs and different spacers and jetting, nothing worked well and even at low speeds and barely any throttle the engine just seemed to surge or act a little off.

Different spark plugs and wires and tried a new distributor cap.
Cranking pressure was 185 PSI on all holes checked with all spark plugs out.
Not knowing the compression and having exhausted all the tuning i cared to do I just figured this thing is getting some 112 octane and see what happens.

It was a different engine!!!
The thing was no longer surging or acting up at steady cruise at low speeds.
You could really tell this as it was a 5 speed stick shift car.

The throttle response was greatly improved and man the power increase it had.

We ran it around with that 5 gallons of fuel for 12 miles then added 4 gallons of 91 on top of that and it ran just as good.

Just needed more octane.

I had pulled timing to 28 total and even tried 38 total and you never heard it ping and did not make much difference how it drove..very odd duck for sure.
Never had an engine act like that.

I tried the same fuel in my V65 magna the 112 octane and turned it into a putz. It was actually quickest with 87 octane and went .2 quicker on 87 than it did on 91. compression was 10.5. You just never know.

You would not think octane would matter when you are steady cruising or just easing off the line with a stick shift.
But that 427" SBC would need a lot of clutch slipping to get it rolling without dying on the 91 octane.

The 112 made it drive like a new car.
If you have it available I would try it.. if nothing else it smells good
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post #30 of 49 (permalink) Old Nov 9th, 18, 7:54 AM
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Re: 496 falling flat

Quote:
Originally Posted by 1bad69 View Post
I did not degree it. I did run it straight up. It starts good and idles good. Sounds good. I have never degreed a cam and this is a Straub Industries cam, I would hope it would be closer to true than the avg cam. But i suppose it could be off. Depending on the cam grinder.
The cam is probably fine. A lot of time itís the timing chain and gear you need to worry about but you need to check it.

69 461" BBC 11.25:1 Compression
840 Rec Heads (2.25/1.88) AED 850 HO carb
Orig Exhaust Manifolds
Straub (Clay Smith) Hyd Roller cam, 288/300 .600/.569 109.
TH400, 3500 stall, 4.11 12 bolt posi
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