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Discussion Starter · #1 ·
Hey guys I'm going to be running the comp 282s cam in my cleve and it has a powerband of 2000-6000. will my bottom end be able to handle shifts at 6000, give or take a few, without balancing the bottom end?

Thanks,
Dustin
 

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it may want to jump off the motor mounts at 2000 rpm. I have a boat motor albeit small block chevy thats out of balance, at 2000 rpm it wants to jump out of the boat. Other motors just thrwon together run like glass. Its a crapshoot
 

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Discussion Starter · #3 ·
Maybe I'm asking a stupid question. If it wasn't "wanting to jump of the motor mounts at 2000" before then why would it want to after I do a cam swap? I am not asking this to offend anyone. I am just trying to understand as I am a little new to building motors.

Thanks,
Dustin
 

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all you did was a cam swap? Thats not gonna affect the balance, or what am I not seeing here? I am tired LOL
 

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Discussion Starter · #5 ·
Maybe I just don't quite understand. About 3 years ago I bought a cleveland shortblock that was rebuilt from a company called Recon. I have put maybe 5000 miles or so on it since.... Would this shortblock assembly already have come with a balanced bottom end? I hear of people building their high rpm motors and getting the rotating assemblies fully balanced to withstand high rpms.

So the question is will the motor I purchased a few years ago be able to withstand 6200 rpms?

Please help me understand

Thanks in advance,
Dustin
 

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as for balance, if you drove it that many miles and it didnt feel ike it was vibrating to death and the bearings are still intact, then I wouldnt worry bout the balance. RPM is limited by valvetrain hardware. Got springs and cam that make no power past 6000rpm, sure it may rev to 6500, just cause the tach is moving doesnt mean anything is happening HP wise. So in summary if the cam and spring you are using has the ability to carry the engine to 6200, then yes. 6200 is nothing crazy by any means.
 

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Discussion Starter · #7 ·
I'm going to replace the rod bearings and main bearings to be sure. I am also going to run the recommended springs for the cam. In fact I already have them on my fresh set of 4v heads. Will the rods be ok at those rpms with stock rod bolts or should I step up to arp?

Thanks,
Dustin
 

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Discussion Starter · #9 ·
Right now they have dished which I am going to try and get by with. I'm not sure how big the dish is. I wish I did. Do you think that I will be able to get by with the dished pistons? Will the arp-154-6003 be the right ones for the stock rods without weakening them by having to drill the rods out for a bigger rod bolt?

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Dustin
 

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Discussion Starter · #11 ·
If the dishes on the pistons are no larger than 20cc I should be close to 9:1 comp. I wish I knew exactly what kind of pistons these are so I could find out the dish size. Will the wave locs go in without any machining on the rods?????

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Dustin
 

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IMO you have to resize the big end of the rod after pressing bolts in. I have seen guys press em in and run em, but on the flipside I have seen more guys do that and spin a rod bearing very quickly.
 

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Discussion Starter · #13 ·
Does anyone have any pics of some 351c dish pistons? I'm trying to find out how big my dish is on the pistons. They look about 13cc

Thanks,
Dustin
 

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Do a full race prep and inspection on the rods or buy H-beam eagle rods, ballance the rotating assembly, get rid of the stock valves...... the 351c block is getting harder to find and when we blow them up its just sad. how sad ? lets just say that if you listen hard you will hear a fat guy in fairfield crying-
 

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balance isn't going to be your biggest worry. Cast, hyper or forged pistons? Cast will crack and then you'll be in trouble. If it's a stock short block and probably is, they're cast pistons. Blasts over 5500 rpms will hurt them and then other parts. Personally being that your short block was a "generic" rebuild, wouldn't risk over 5500 rpms with some serious bottom end work.
 

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Gees, only 5000 miles on reconned motor. I would just stick in the cam, make sure the heads are up to it and hit 6000rpm. I wouldn't be too concerned with only that low of rpm.

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<font size=-1>[ This Message was edited by: xdclevo on 9/3/06 4:40pm ]</font>
 

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Heya dion


Yeah I agree with xdclevo as I had a stock reco 351c back in 94-5ish and I upgraded it by way of carb cam and extractors (hedders)and run it up to 6500 on a regular basis no worries!

It was an A341 motorsport grind with matching springs, stock rockers a 750vac holley on a stock aussie spreadbore manifold using an adaptor and 1 and 3/4" pipes and it hung together for 2 hard years through burnout comps and all so yeah I think 6000 is easy. If your at it I would invest in some good rod bolts for a bit of insurance though.

ps. xyfmtjoe dion
 

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well,if your engine is outta the car id be measuring those dishes and finding out exactly where the compression is at.if you are going to be around 9-1 id ditch those pistons and buy the right set.
its all good to throw a cam in an engine ,hold your foot flat and rev it to 6k,but if the combo aint right chances are you are not making any power up there,just wasting time .
youre putting all this into your engine,dont half-arse it,do it right.
Ive learnt that its not worth cutting corners,i used stock rods with upgraded bolts,hyper pistons when i rebuilt my engine,big mistake.
every time i spun it to 6k+ i was waiting for something to let go,so im spending the cash twice doing it right.
what compression ratio does the cam manufacturer say to run with the cam you are going to use?
 

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That 282s cam wants a minimum of 9:1 compression. Thats why I originally asked about the pistons and I think he'll be running the raged edge for not quite enough compression. But, maybe it will be spot on.
 

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On 2006-09-03 03:01, Clevo71 wrote:
Heya dion


Yeah I agree with xdclevo as I had a stock reco 351c back in 94-5ish and I upgraded it by way of carb cam and extractors (hedders)and run it up to 6500 on a regular basis no worries!
Hey mate, how you going?
Yeah, i have had a similar stock cleveland in the past and revved to 6000 rpm for 3 or 4 years on my streeter, and i was 18 when it started, so was a bit hard on everything. If kept at that rpm and not running your tune on the ragged side, all should be fine. But if you want to upgrade cam/heads again soon, you may as well do the lot now really.

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<font size=-1>[ This Message was edited by: xdclevo on 9/4/06 5:28pm ]</font>
 
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