Re: 383 HP 330vs335 hp
[Re: 70 buzz]
#2308528
05/21/17 02:50 PM
05/21/17 02:50 PM
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Joined: Mar 2004
Posts: 8,948 Harlan, Iowa
69CoronetRT
master
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master
Joined: Mar 2004
Posts: 8,948
Harlan, Iowa
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The only way to truly know what any specific engine puts out is with a dyno.
Estimating actual horsepower based on a, probably, inaccurate factory rating is probably not a good idea. Only a dyno would give you the facts.
Seeking:
1969 St. Louis plant VINs, SPD, and VONs. Over 2,000 thanks to you!
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Re: 383 HP 330vs335 hp
[Re: Cab_Burge]
#2308550
05/21/17 03:37 PM
05/21/17 03:37 PM
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Joined: May 2005
Posts: 784 Florida
cbusters
super stock
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super stock
Joined: May 2005
Posts: 784
Florida
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Here you go, fresh from the DC Racing Manual circa 1979. Let me clarify that I didn't doubt that you read that in a Mopar manual, what I should have said that I jhave never seen a production 383, from 1959 to 1971, that had the stock OEM piston tops above the decks You need to remember that the original beaded steel head gaskest where .022 thick and had a smaller bore size than the later 440/400 bore size .017 thick beaded steel head gaskets Which leads me to say do not believe every thing you see in print Have you heard the old adage to not believe any thing you hear and only half of what you see Many myths out there. Mopar, Chevy and Ford provided many false specs. to NHRA, NASCAR and other sanctioning racing organizations on many different parts they made for racing only that where not used on production cars I can verify it past the reading stage. I actually rebuilt engines with the taller pistons. It was a Mopar thing, not a slop thing or an aftermarket thing. I had a daily driver 69 RR that got too cold and froze and blew open the block. I found another block and then we first found out about the pistons when we rebuilt it and only needed to replace one. I will say it is past the myth stage here. Believe as you wish.
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Re: 383 HP 330vs335 hp
[Re: cbusters]
#2308556
05/21/17 03:42 PM
05/21/17 03:42 PM
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Joined: Feb 2005
Posts: 4,333 Prospect, PA
BSB67
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Joined: Feb 2005
Posts: 4,333
Prospect, PA
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Here you go, fresh from the DC Racing Manual circa 1979. Right, but that does not necessarily make it so from the factory. I'm still waiting for someone that has measured a factory original that is proud. Between the ones I've measured, and people that I trust that have measured them, I have not heard of any being positive. There could be some due to factory tolerance differences, but I have not seen or heard of any. They ranged from very near zero to 0.008" below. I have run 915 head on a 1.932" CH 68 383.
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Re: 383 HP 330vs335 hp
[Re: NachoRT74]
#2308568
05/21/17 04:02 PM
05/21/17 04:02 PM
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Joined: Jan 2003
Posts: 20,328 Park Forest, IL
slantzilla
Too Many Posts
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Too Many Posts
Joined: Jan 2003
Posts: 20,328
Park Forest, IL
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NHRA Stock specs are what is allowed in teardown. It has nothing to do with factory specs.
"Everybody funny, now you funny too."
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Re: 383 HP 330vs335 hp
[Re: slantzilla]
#2308666
05/21/17 07:54 PM
05/21/17 07:54 PM
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Joined: Aug 2003
Posts: 43,719 Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,719
Bend,OR USA
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NHRA Stock specs are what is allowed in teardown. It has nothing to do with factory specs. According to NHRA tech. directors when I started racing NHRA in 1973, Farmer Dismuke and Jim Dale, and the other directors that have served as NHRA Tech directors since them all say that NHRA only uses the engine and car specs. furnished to them from the car makers Back in the early days of SS and stock Grumpy Jenkins proved to NHRA and probably Plymouth racing division that the piston dome height for the 1963 415 HP M.W. motors was incorrect for the advertised compression ratio. stock was between + .062 and + .065 from TRW, they needed to be + .091 to have the true compression ratio Plymouth and Dodge said they had according to the math. NHRA changed their spec. after that to allow the +.091 dome height on those motors in 1965 or 1966 The only way to get a OEM legal stock piston to measure that was to use a 1964 415 HP piston and mill the top down from +.120 to +.123 to +.091 To much politics in every form of competion
Last edited by Cab_Burge; 05/21/17 07:56 PM.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: 383 HP 330vs335 hp
[Re: NachoRT74]
#2309039
05/22/17 01:36 PM
05/22/17 01:36 PM
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Joined: May 2017
Posts: 27 NY,USA
Bad B-rad
member
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member
Joined: May 2017
Posts: 27
NY,USA
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Well some people on here had asked how much above deck it sat, that's why I mentioned the dial indicator. As I said on my engine, at TDC it totally appears to be above the deck just a small amount,so small that you would need a dial indicator to measure how much above the deck. And then we would have a measurement to use for future discussions.
I only pulled my heads do to stuck valve, so I did not think to check and measure piston deck height, but as I rotated it to check cylinder walls I noticed pistons looked to be above the deck a small amount.
So I understand you don't HAVE to have a dial indicator to tell if its positive deck height but to have an actual number vs a guess seams like a small bit of useful info.
Also zero deck ht and 0.008 above or below is very hard to see by feel or sight.
Last edited by Bad B-rad; 05/22/17 01:43 PM.
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Re: 383 HP 330vs335 hp
[Re: Bad B-rad]
#2309211
05/22/17 05:48 PM
05/22/17 05:48 PM
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Joined: Aug 2011
Posts: 2,904 Pattison Texas
CSK
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master
Joined: Aug 2011
Posts: 2,904
Pattison Texas
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Well some people on here had asked how much above deck it sat, that's why I mentioned the dial indicator. As I said on my engine, at TDC it totally appears to be above the deck just a small amount,so small that you would need a dial indicator to measure how much above the deck. And then we would have a measurement to use for future discussions.
I only pulled my heads do to stuck valve, so I did not think to check and measure piston deck height, but as I rotated it to check cylinder walls I noticed pistons looked to be above the deck a small amount.
So I understand you don't HAVE to have a dial indicator to tell if its positive deck height but to have an actual number vs a guess seams like a small bit of useful info.
Also zero deck ht and 0.008 above or below is very hard to see by feel or sight. Feeler gauges work pretty well .
1968 Charger COLD A/C Hilborn EFI 512ci 9.7 compression, Stealth heads, 4.10 gear A518 ODtrans 4100lb,10.93 full street car trim 2020 T/A 392 Stock 11.79 @ 114.5
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Re: 383 HP 330vs335 hp
[Re: CSK]
#2309268
05/22/17 07:29 PM
05/22/17 07:29 PM
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Joined: Feb 2005
Posts: 4,333 Prospect, PA
BSB67
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master
Joined: Feb 2005
Posts: 4,333
Prospect, PA
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So I understand you don't HAVE to have a dial indicator to tell if its positive deck height but to have an actual number vs a guess seams like a small bit of useful info.
Also zero deck ht and 0.008 above or below is very hard to see by feel or sight.
Feeler gauges work pretty well . This.
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Re: 383 HP 330vs335 hp
[Re: JohnRR]
#2309306
05/22/17 08:24 PM
05/22/17 08:24 PM
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Joined: Nov 2004
Posts: 173 Milano, Italia
FK5
member
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member
Joined: Nov 2004
Posts: 173
Milano, Italia
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My 69 383 4bbl A/C car has duel exhaust,with what looks to be factory "H" pipe and hangers and mufflers. And I now think I figured out the yellow crayon 68 written on the front of my pass side valve cover is not a 68 it is an 899 and one 9 is gone and its written upside down. I will now have to go see if the pipes and mufflers have any numbers on them so I can figure out this semi-mystery!!!
Also do 383HP MAGNUM ROAD RUNNER 335Horse engines use the same pistons as 383 330horse pistons, or do the 335horse motors have valve pockets in them? Could you put a "RoadRunner/Magnum" cam in the 330hp 383 with 2bbl cam with out causing any damage? I know my engine(330horse) the pistons almost have a positive deck height at TDC. Someone changed the headpipes on that car, there isn't an H pipe on any 383 Mopar , only on 440hp, 6pk 70/71 and Hemi cars. Um... what? Pretty sure this is bum info too. I have a 375 hp/440 'cuda from 1970 and it doesn't have any h-pipe either. I was there when we picked it up at the dealer.
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Re: 383 HP 330vs335 hp
[Re: NachoRT74]
#2309873
05/23/17 04:17 PM
05/23/17 04:17 PM
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Joined: May 2017
Posts: 27 NY,USA
Bad B-rad
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member
Joined: May 2017
Posts: 27
NY,USA
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I was wrong, My car(69 charger 3834Bbl A/C) does NOT have an H-pipe, It is straight duel exhaust. I am sorry about that. I guess I have been under way to many Mopars as of late,thats a good and bad thing,LOL.
But now I am Making time for my car, so I should be getting to know it better. I got in late Dec,16, and I have not done very much, but look at it, and sit in it making Vroom, Vroom sounds.
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