Re: Problems with Hughes Whiplash cam in 383
[Re: elmor353]
#2480712
04/10/18 08:44 PM
04/10/18 08:44 PM
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Joined: Mar 2005
Posts: 1,406 New Jersey, USA
yella71
pro stock
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pro stock
Joined: Mar 2005
Posts: 1,406
New Jersey, USA
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Call me what ever you want... the reason I don't ask questions here is ive NEVER gotten a correct answer to anything ive asked. oh and you still don't know whats wrong do you? nor does anyone else, I told you what I would check so there you go good luck
Last edited by yella71; 04/10/18 08:46 PM.
71 challenger convertable, 64 sport fury 383 ci with factory air
99 sebring convertable
89 CTD pup
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Re: Problems with Hughes Whiplash cam in 383
[Re: elmor353]
#2480900
04/11/18 02:10 AM
04/11/18 02:10 AM
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Joined: May 2008
Posts: 5,399 Aurora, Colorado
451Mopar
master
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master
Joined: May 2008
Posts: 5,399
Aurora, Colorado
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What was done to freshen up the engine? Were the pistons replaced or heads milled? Just curious as the piston to valve clearance might be tight with 242 exhaust duration @ 0.050?
I think you said cam was installed straight up? So we really don't know the exact installed position? You could maybe just do a quick check that the intake valve is at max lift around 102-degrees ATDC?
I'd start with the basics, pull the plugs and inspect them, then do a compression check. Leak-down check if you have the equipment.
If that looks good, you do need to re-curve the distributor as mentioned earlier for maybe 18-20 degrees mechanical advance in the plate, and around 16-degrees initial timing at idle (with no vacuum advance.) Idle will likely need to be higher than normal too, and at idle the carb may be exposing the transition circuit. Check how much of the transition slots are exposed. You might have to drill the throttle blades if exposing to much of the transition circuit. Not sure if the drilled throttle blades is still the correct tuning adjustment? I think the Demon carbs have an adjustable idle air adjustment, and there may be a better way to correct that?
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Re: Problems with Hughes Whiplash cam in 383
[Re: Mattax]
#2480992
04/11/18 11:13 AM
04/11/18 11:13 AM
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Joined: Feb 2003
Posts: 21,318 Manitoba, Canada
DaytonaTurbo
Too Many Posts
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Too Many Posts
Joined: Feb 2003
Posts: 21,318
Manitoba, Canada
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IMO the shortening the slots (whether by welding or using the FBO plate) is putting the cart before the horse. First see if changing the initial timing resolves some or all of the issue. Then see what the rest of the timing curve looks like. With that info, adjust the spring perches and/or the slots as needed. Agreed. Bumping the initial just to try it is free, quick and easy. I would play with that before spending money or going deeper.
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Re: Problems with Hughes Whiplash cam in 383
[Re: elmor353]
#2481420
04/12/18 01:42 AM
04/12/18 01:42 AM
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Joined: Jan 2003
Posts: 1,908 Nebraska
4406bbl
top fuel
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top fuel
Joined: Jan 2003
Posts: 1,908
Nebraska
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I did a 383 for a guy with that hughes cam, lifters, and springs, straight up, pistons a mile down, milled heads got it to 8.9 to 1 measured, pocket ported heads, old weiand dual plane, 100% stock older 3310, 18 degree in dizzy, 20 on the crank, exhaust manifolds and it runs fine. Its a bad combo but a bunch of old parts he wanted to use up, it sounds meaner than it runs, but will idle all day on cheap gas no matter how hot it is, which is what he wanted. Best advice all the initial timing you can get.
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Re: Problems with Hughes Whiplash cam in 383
[Re: elmor353]
#2481634
04/12/18 02:07 PM
04/12/18 02:07 PM
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Joined: May 2008
Posts: 5,399 Aurora, Colorado
451Mopar
master
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master
Joined: May 2008
Posts: 5,399
Aurora, Colorado
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Freshening up consisted of new rings and bearings, gaskets and a valve job. The head surfaces were straight and flat, so surfacing was not needed. Pistons are a mile in the hole, so I'm not too worried about piston to valve clearance. I degreed the cam and it was installed to Hughes recomendations. I haven't been able to work on it for a week, because of the weather. Maybe soon, it is spring in Oregon! Sounds good, likely just need to work on the tune. Was asking because on my 383, I used the pistons that are at zero deck height and no valve reliefs, and the heads were milled. when I checked piston to valve clearance (smaller cam than yours) the clearance was closer than I thought it would be.
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Re: Problems with Hughes Whiplash cam in 383
[Re: elmor353]
#2481687
04/12/18 03:47 PM
04/12/18 03:47 PM
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Joined: Apr 2012
Posts: 59 Florida
Sweet5ltr
member
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member
Joined: Apr 2012
Posts: 59
Florida
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First step, purchase a vacuum gauge. Give us the reading @ idle and while in gear.
Second step, add more initial timing.
Then let's go from there!
Hope you get it sorted out.
1969 Plymouth Road Runner (440 w/ Boost! RIP) now a low-deck 470 with hotchkis suspension, nascar boom tube exhaust, & big brakes.
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Re: Problems with Hughes Whiplash cam in 383
[Re: elmor353]
#2482149
04/13/18 01:45 PM
04/13/18 01:45 PM
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Joined: Jan 2003
Posts: 21,510 A collage of whims
topside
Too Many Posts
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Too Many Posts
Joined: Jan 2003
Posts: 21,510
A collage of whims
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You could subtract 20 degrees of overlap Int & Exh and it would be a much better street cam. Especially with low CR. Ran an Engle in a 406" SB street motor - 214/224 @.050, .470/.504, 110 CL - and it ran great: perfect throttle response even with stock converter, 3.23 gear, 28" tire, handled AC, pulled 17 MPG, but still sounded pretty rumpity. Rarely have I seen a street car where the rumpity idle was the main build consideration actually run well @ lower RPMs. I scaled that SB Engle up 1 lobe spec Int/Exh for a 446" RB street build, and got the same results in a 4-speed early-B wagon.
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Re: Problems with Hughes Whiplash cam in 383
[Re: elmor353]
#2482388
04/14/18 12:33 AM
04/14/18 12:33 AM
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Joined: May 2003
Posts: 15,487 Florida
scratchnfotraction
I Live Here
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I Live Here
Joined: May 2003
Posts: 15,487
Florida
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my speed shop said now way with stock everything..LOL!
750cfm eldelbrock holley street dominator 440 whiplash cam/springs headers-3" pipes/muffs 12" low stall TC 727 used 2.76 3.23 3.91 gears turning a 29x15x15 m/t all street friendly
dist locked 0* 36* total
I drive it daily/weekends and have clocke 10,000 miles now. great daily drive if you got gas $$
Last edited by scratchnfotraction; 04/14/18 12:37 AM.
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