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Re: Magnum Conversion Woes
[Re: dgc333]
#88906
07/17/08 03:10 PM
07/17/08 03:10 PM
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Joined: Jan 2003
Posts: 17,864
S.E. Michigan
ZIPPY
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 17,864
S.E. Michigan
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Quote:
Stock magnum head valves have a single round profile groove.
I was thinking about LA engines, sorry.
I have two sets of magnum r/t's on the shelf, one of them assembled, but never even looked at the valves!
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Re: Magnum Conversion Woes
[Re: ZIPPY]
#88907
07/17/08 04:04 PM
07/17/08 04:04 PM
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Joined: Jan 2003
Posts: 16,123
Grand Haven, MI
patrick
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 16,123
Grand Haven, MI
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I always forget about hughes engines, mainly because their stuff is so gosh darn expensive....part number 1282 (retainers) look promising for maybe increasing your installed height some over the stock GM retainers.
1976 Spinnaker White Plymouth Duster, /6 A833OD
1986 Silver/Twilight Blue Chrysler 5th Ave HotRod **SOLD!***
2011 Toxic Orange Dodge Charger R/T
2017 Grand Cherokee Overland
2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)
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Re: Magnum Conversion Woes
[Re: patrick]
#88908
07/17/08 04:24 PM
07/17/08 04:24 PM
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Joined: Aug 2004
Posts: 260
N. Ontario, Canada
John_M
OP
enthusiast
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OP
enthusiast
Joined: Aug 2004
Posts: 260
N. Ontario, Canada
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Quote:
... smaller coil diameter, larger wire diamter and/or less coils=stiffer spring rate...
So would replacing the Chev springs with the MP P5249464 R/T springs and retainers solve the problem or would you expect those springs to bind at the same place?
Quote:
I'm suprised your mechanic is saying they coil bind at .465", as based on my tested coil bind height, with your installed height, they should coil bind at ~.517". with the recommended .060 min clearance, you wouldn't want to run more than ~.457" lift with your installed height.
With the springs, retainers and valves in their installed position he set the tip of the dial indictor directly at the top of the spring. He then set the dial pointer to 0.000`. I watched the dial as he compressed the spring with a small pry bar and when it would not compress any more the dial indicator read 0.465".
Quote:
so it looks like you have 2 options:
1) machine the spring pocket .060 for more installed height
2) find some MP or 2.2L retainers, and measure the installed height of those. with that info, scour the catalogs for a ~1.4" OD spring who's coil bind height is short enough to give you enough lift and clearance, and have adequate spring rate and seat pressure.
Why would this setup work on some engines and not on others?
By the way, thank you very much for the responses.
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Re: Magnum Conversion Woes
[Re: patrick]
#88909
07/17/08 04:49 PM
07/17/08 04:49 PM
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Joined: Feb 2004
Posts: 4,501
Gainesville,FL
goldmember
master
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master
Joined: Feb 2004
Posts: 4,501
Gainesville,FL
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Dave at Hughes "thinks",PN 1110 spring $88.00 along with PN 1278 retainers $62.00 will work for a typical hyd flat tappet.520"lift around 120lbs seat. I'm helping a "friend" with a low buck magnum hop up. It sure was easier with SBchevy +.100 valves 10 years ago. Don't cut the spring seats down if you can avoid it.
Last edited by goldmember; 07/17/08 04:51 PM.
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Re: Magnum Conversion Woes
[Re: goldmember]
#88910
07/17/08 05:05 PM
07/17/08 05:05 PM
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Joined: Aug 2004
Posts: 260
N. Ontario, Canada
John_M
OP
enthusiast
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OP
enthusiast
Joined: Aug 2004
Posts: 260
N. Ontario, Canada
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Quote:
Dave at Hughes "thinks",PN 1110 spring $88.00 along with PN 1278 retainers $62.00 will work for a typical hyd flat tappet.520"lift around 120lbs seat. I'm helping a "friend" with a low buck magnum hop up. It sure was easier with SBchevy +.100 valves 10 years ago. Don't cut the spring seats down if you can avoid it.
Have you ordered these springs and retainers? Would they be a suitable alternative in this situation for the MP P5249464 springs and MP P4452032 retainers - or the Chev 3800 springs for that matter?
Is the installed height they list installed in magnum heads with stock magnum valves and locks?
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Re: Magnum Conversion Woes
[Re: cudaman1969]
#88913
07/17/08 05:38 PM
07/17/08 05:38 PM
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Joined: Aug 2004
Posts: 260
N. Ontario, Canada
John_M
OP
enthusiast
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OP
enthusiast
Joined: Aug 2004
Posts: 260
N. Ontario, Canada
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Quote:
i have the magnum heads with the 380 hp cam and 1.7 rockers with the mopar upgrade springs and no spring bind at roughly 535 lift (actual 515 because of the pushrod lifter not aligned) springs where only about eighty dollars from the race catalog. throw those springs away. one more thing get the new keepers also.
Do you recall if you installed the MP P5249464 springs and MP P4452032 retainers. Best price I could find for the MP springs was $11 a piece or $8 a piece for the MP hi-lift ones (P4876062).
Since my rockers are 1.6:1 would that reduce the lift? Thanks.
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Re: Magnum Conversion Woes
[Re: tpabayflyer]
#88915
07/18/08 03:54 PM
07/18/08 03:54 PM
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Joined: Aug 2004
Posts: 260
N. Ontario, Canada
John_M
OP
enthusiast
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OP
enthusiast
Joined: Aug 2004
Posts: 260
N. Ontario, Canada
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Had you considered the Chev springs and retainers TBF - and if so, why did you decide upon the MP equipment?
Last edited by John_M; 07/18/08 04:21 PM.
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Re: Magnum Conversion Woes
[Re: John_M]
#88916
07/18/08 05:15 PM
07/18/08 05:15 PM
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Joined: Jan 2003
Posts: 1,586
Tampa, FL
tpabayflyer
pro stock
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pro stock
Joined: Jan 2003
Posts: 1,586
Tampa, FL
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I already had them on hand from a previous magnum head conversion on my old 'Cuda 360.... TBF
71 Challenger 528 Hemi project
09 Gr Cherokee 5.7 hemi in da house!!
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