Post deleted by Defbob
[Re: RyanJ]
#610801
02/11/10 07:58 PM
02/11/10 07:58 PM
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Anonymous
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Anonymous
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Re: 426 MP Crate Motor Compression?
[Re: dartman366]
#610804
02/11/10 08:37 PM
02/11/10 08:37 PM
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Joined: Jan 2003
Posts: 8,547 State College, PA
RyanJ
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Well I dunno what it had in it from MP, some small Hyd FT. I'm putting a mild roller in it, 254/258 on 108 LSA. I don't have cam card in front of me, but lift is in the .650" range.
I finished heads up @ beginning of week, OOB they went like 303 cfm? Exhaust was just horrifficly bad 170's? Don't remember exactly.... I did real basic work to them & bumped into the low 350's/230's with no tube. This is just supposed to be mid/low 11 sec motor in a '70 HemiCuda, nothing special.... Rod bearing clearance was @ .0008"... yes I wrote that correctly. Mains were .0013"-.0014". Had to take crank .010/.010 to fix that mess. Actually more like .011"/.011" but.... I got it it set around .0031" Mains, .0027" rods now with 3/4 Groove Federal mains & set of H Clevites on rods to replace the factory stuff.
Was just surpirsed to see compression was as low as it was. I've never CC'd a Hemi head before, I don't know if 117 is high or what. They have fully machined chambers in them so, not alot of room for error there.... Piston looks like a Wiseco? This is an older Cummins built 426 Crate not a newer Stanton motor BTW.
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Re: 426 MP Crate Motor Compression?
[Re: maximum entropy]
#610806
02/11/10 08:43 PM
02/11/10 08:43 PM
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Joined: Nov 2003
Posts: 6,293 Rock Springs
Bob_Coomer
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master
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Rock Springs
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Im not surprised at all. Can those heads be milled that much? I figure with that much cutting the valve seat would be hanging in the chamber or physically be cut into at that point. Here is a pic of probably the same heads if its a new Crate engine. These are cast by Edelbrock BTW
[color:"red"]65 Hemi Belvedere coming soon [/color] [color:"#00FF00"]557" Indy engine 1.07 60ft 144mph in the 8th 2100 lbs package [/color]
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Re: 426 MP Crate Motor Compression?
[Re: Troy]
#610807
02/11/10 08:43 PM
02/11/10 08:43 PM
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Joined: Jan 2003
Posts: 8,547 State College, PA
RyanJ
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Quote:
I have measured a few engines myself and found them to be in the 8.2+/- range.
That's what I wanted to hear, that I'm not crazy..... I'm sure the guy who owns this thing is going to want to bash my head in with a baseball bat after seeing his bill go up & up & up with every problem I have found, but..... It's just been a mess.
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Re: 426 MP Crate Motor Compression?
[Re: RyanJ]
#610809
02/11/10 10:07 PM
02/11/10 10:07 PM
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Joined: Nov 2003
Posts: 2,715 closer to Canadian beer!
torkrules
I'm neurotic
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I'm neurotic
Joined: Nov 2003
Posts: 2,715
closer to Canadian beer!
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Quote:
Anybody ever check one of these things? I got 177.5 on chambers, & Dome volume around 62.2 CC?????? 7.95:1 Compression?
Only thing I've done was VJ, & blended seats into chambers..... But that did'nt kill point of compression... looks to me, I'm going to have to mill heads around .080" to get it up to 9:1 where it is advertised?
Those old MP motors are rife with problems. Tim at FHO told me stories that would make your head spin. I was the lucky recipient of a 472. I knew what I was getting into and having said that the amount of problems I had to fix still has me shaking my head.
In hind sight I would have been financially better off buying all new parts.
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Re: 426 MP Crate Motor Compression?
[Re: RyanJ]
#610811
02/13/10 09:31 AM
02/13/10 09:31 AM
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Joined: Nov 2003
Posts: 2,503 Illinois
CRE2004
super gas
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super gas
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Posts: 2,503
Illinois
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Quote:
This is an older motor W/ Iron MP heads on it. I can cut them to edge of 45* intake seat if need be.... Just sucks I have to cut them that much as the manifold will have to follow suit... driving costs up.
The SB 360 Crate motors always seemed to be much closer to advertised compression, that's why I was surprised to see it so far off.
Ryan, what was the deck height? I'd whack the decks before I'd think of cutting those heads that much. Keep in mind, it's not a wedge.
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