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Old September 16th, 2008, 02:39 PM   #21
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Who the hell talked her into this one?
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Old September 16th, 2008, 02:51 PM   #22
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x2. I had some junk amc parts sitting in my garage, and nobody to buy them. so I found a girl who doesn't know much about engines and sold her all the junk for top dollar.
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Old September 16th, 2008, 04:43 PM   #23
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x2. I had some junk amc parts sitting in my garage, and nobody to buy them. so I found a girl who doesn't know much about engines and sold her all the junk for top dollar.
oo..call me next time, I love paying too much for junk amc parts.
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Old September 16th, 2008, 04:53 PM   #24
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how much advance are you running?

Just go up in octane until the spark knock goes away, or retard the timing.
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Old September 16th, 2008, 04:58 PM   #25
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one word ............... E85 :)
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Old September 16th, 2008, 05:06 PM   #26
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x2. I had some junk amc parts sitting in my garage, and nobody to buy them. so I found a girl who doesn't know much about engines and sold her all the junk for top dollar.
Would you prefer we discuss how she really got her $250 401? It was easier to just pin it on you.
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Old September 16th, 2008, 05:15 PM   #27
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Man, if its really that high, and you don't want to tear it up, I would be looking at running E85 or Propane or something.

I have run 11.3:1 on 93 successfully, but that was an aluminum head, big cam honda motor with some tuning.

12.5:1 on an iron head 70's V8 in a Jeep seems like a real recipe for disaster.
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Old September 16th, 2008, 05:24 PM   #28
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She texted me earlier and confirmed they are 1974 58cc heads and not the 52's, so that'll be helpful here.
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Old September 16th, 2008, 07:46 PM   #29
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She texted me earlier and confirmed they are 1974 58cc heads and not the 52's, so that'll be helpful here.
So, is the 12.5:1 a guess, or was it calculated off something?

Were the heads actually cc'd? What about the block/piston/rod/crank combo..... any idea how much much piston volume there is at TDC?
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Old September 16th, 2008, 07:51 PM   #30
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the thing runs pretty damn perfect, just need to advance timing slightly but can't because of the distributor hitting the power steering pump. have rotate it a tooth. also have to put in some smaller jets..
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Old September 16th, 2008, 08:08 PM   #31
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So, is the 12.5:1 a guess, or was it calculated off something?

Were the heads actually cc'd? What about the block/piston/rod/crank combo..... any idea how much much piston volume there is at TDC?
The 12.5 was an "estimate" that someone shit somewhere along the way. I wasn't clear on whether it was the piston supplier or the engine builder, but it didn't really sound like it was based on any math. I asked her about some of the different things she had done that could increase or decrease compression, but it doesn't sound like all that stuff was recorded. Probably won't get a real number without pulling a head and measuring, but it doesn't sound like that's necessary so far.

She also mentioned that while the block was decked and the heads were milled, the intake was not. Not sure if enough was taken off for it to matter as she didn't recall any numbers from memory, but the intake can always be fixed later.

It may run fine now, but it was always a different story under load on all the AMC V8's I've had. Hopefully the fact that it has the larger chambers will give enough of a cushion to run on 93 and she can put in something higher and advance it for "special occasions".
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Old September 16th, 2008, 08:21 PM   #32
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Wonder what pistons are in it.. I guess I'd try it and take care with the right foot till you know it isn't gonna knock.. If they are Hyper KB's then they won't take much knocky knocky till they come apart.. forged will give you a "little" more room for error but not much. Just for giggles I'd be curious to see what the compression gauge says.. Not that it's 100% accurate in determining compression ratios it will tell you if it's "really high"

Here is a link that is kinda helpfull.. Again not 100% accurate but at least it'll give you a idea of what you have.. big thing you need to have is the cam duration and rod to stroke ratio..

http://www.not2fast.com/turbo/compre...pressure.shtml

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Old September 16th, 2008, 08:30 PM   #33
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IMHO, and not what you want to hear, but if you can't get 93 to run it'll be worth a quick teardown (just pull the heads) and take some measurements to get a better idea. you'll be able to figure out if you can get away with a bigger head gasket.

BTW,

smaller jets will only increase knock. I wouldn't mess with carburetion without having a WRAF sensor.
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Old September 17th, 2008, 12:34 AM   #34
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kelly i have a wide band somewhere's we could tune it
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Old September 17th, 2008, 01:16 AM   #35
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The Edelbrock website has a sweet jetting chart PDF file for them carbs. Ive followed the charts on my carb and got the calibration kit..real quick and easy to tune!
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Old September 18th, 2008, 08:01 PM   #36
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we've allready decresed the richness 8% according to edelbroks calibration pdf needs get the next size smaller jets still, but I dont think my compression is 12.5:1 anymore...

pistons 10.5:1 (not sure if that was for 52cc heads or the 58cc. I have 58cc)
block decked and bored .030
heads milled/port/polished
edelbrok preformer intake that was not milled down
head gaskets are felpro, but I dont remember choosing a thickness..
HEI distributor
.010 off the crank I think


CAM:.490/.490 lift with 1.6 rocker ratio
110 degree lobe separation
RPM power range 2000-6000



oh .. and of course its not going to be a DD, I have a mustang DD

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Old September 18th, 2008, 08:09 PM   #37
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These are her pistons.

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Old September 18th, 2008, 08:17 PM   #38
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Those look like a Dish?? I'd say you'll be fine.. I say get some brakes and give it a run.. :)
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Old September 18th, 2008, 08:20 PM   #39
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Those look like a Dish?? I'd say you'll be fine.. I say get some brakes and give it a run.. :)
Yup. I'm thinking that they have have been intended for the 52cc heads. Not too concerned about the compression anymore. Once the motor is timed, it would be nice to check the cylinder pressures.
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Old September 18th, 2008, 08:27 PM   #40
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These are her pistons.

those have a big dish there is no way its 12 to 1. with a flat top maybe but not with those
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