525SC max lift with stock pistons
03-10-2018 | 05:55 AM
#1
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525SC max lift with stock pistons
Anyone know if the stock piston in a 525 is dished or what to get the 7.5 compression? Going to put rollers in them and wanted to know my options as far as lift goes. Any help would be awesome thanks!
03-10-2018 | 05:52 PM
#6
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From: Grand Rapids, MI
A lot of information on the 525sc in the tech section...
The cam is a Crane #132561
Specs are 228/236 .530/.551 on a 114 lobe sep.
The ignition timing curve is set up with 13* base timing and 22* advance. It advances to 25* by 2000rpms and then gradually advances up to full advance of 35* by 4500rpms.
Carb is a 1050 dominator
Jets are 98's all around--I think(Holley #122-98)
6.5 PV's front & back
#35 Acelerator nozzles
50cc acc pumps front & back
Acc pump cams-frt& rear--white-use # 1 hole.
Boost is set at 5.5# stock with a 2:1 ratio
Pistons are dished forged TRW / Speed Pro #L2453
Valves are 2.19/1.88
Specs are 228/236 .530/.551 on a 114 lobe sep.
The ignition timing curve is set up with 13* base timing and 22* advance. It advances to 25* by 2000rpms and then gradually advances up to full advance of 35* by 4500rpms.
Carb is a 1050 dominator
Jets are 98's all around--I think(Holley #122-98)
6.5 PV's front & back
#35 Acelerator nozzles
50cc acc pumps front & back
Acc pump cams-frt& rear--white-use # 1 hole.
Boost is set at 5.5# stock with a 2:1 ratio
Pistons are dished forged TRW / Speed Pro #L2453
Valves are 2.19/1.88
03-11-2018 | 01:12 AM
#8
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Joined: Oct 2000
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From: Omaha/LOTO
I upgraded to the Crane 731 (.587/.610) in my old 525SC. IMO, it was plenty of cam for the engine spinning up to 5300rpms.
You could go with more cam and spin it higher, but have to change the stock rev limiter.
Also, then the blower is going to spin even faster Max blower rpm is rated at 13000 rpms.
You could go with more cam and spin it higher, but have to change the stock rev limiter.
Also, then the blower is going to spin even faster Max blower rpm is rated at 13000 rpms.
03-11-2018 | 01:36 PM
#9
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From: NW Michigan
Like griff said the 731 cam is excellent upgrade for 525. The only time I ran into a clearance issue was with a cam I had initially wanted to advance, 454 with stock mag pistons. It was either flycut the pistons etc or install straight up. .600 lift cam with 2.300 valve - dart heads decked .025. You have stock heads with 2.19 int. With dial indicator and valve compressor you could carefully check at full lift with your current cam although shoukd use a solid lifter when checking if you so choose to do however I see no clearance issues. Be careful what cam you choose. Valve timing is crucial.
