piston notching?

Fostang · 02-17-2002, 11:28 AM

I've got a 5.0 out of a cougar that I'm trying to build into an HO. The pistons aren't notched therefore I can't add bigger rockers or cam the engine is out and in pieces. I wanted to know what would be the best way to notch them? Also what year could this engine be and does it have forged pistons also?

NO SLO PK · 02-18-2002, 01:13 AM

Fostang, you can notch the pistons without disassembling the short block. I had this done on my old engine while it was still in the car. Iskendarian makes a special notching tool that uses a junk head as a guide. The Isky tool is just a grinding bit, in the diamteter of a valve relief. The tool fits inside the valve guide of the scrap head. Connect the shaft of the Isky tool to a 1/2" drill, and you've got your valve relief cutting tool.

The piston has to be brought to TDC during the grinding. You might lose a gram or so of engine balance. The alternative seems to be disassembling the short block and sending the internals to a machine shop for cutting and balancing.

Hope this helps.

Nitrous Al · 02-18-2002, 07:11 PM

The pistons in that motor are cast, not forged. If you are going to tear it down to notch the pistons, buy a set of forged pistons for a 5.0 HO. The 5.0 HO pistons are also dished with the notches. I did a little research on the 5.0 HO conversion because I'm looking for an '86-'91 Crown Victoria/Grand Marquis as a daily driver. My girlfriend is tired of driving my truck so I'm going to get a car. A Crown Victoria or Grand Marquis with a modified 5.0 HO would be the perfect sleeper. The '94-'96 Impala SS only made 220 at the rear wheels. 300 hp at the wheels should scare a few Camaros and Imports out there and there's always nitrous.

Fostang · 02-19-2002, 11:50 AM

What would be the down fall of the engine not being balanced?

DRASTiK · 02-19-2002, 12:50 PM

well depending on how off the balance is would determine the severity of the effects. Mostly it would shorten the life of the engine, and cause vibrations throughout the entire car. If it's way out of balance, it could be worse.

02-17-2002, 11:28 AM	#1
Fostang Registered Member Join Date: Feb 2001 Location: Stockton, Ca Posts: 599	piston notching? I've got a 5.0 out of a cougar that I'm trying to build into an HO. The pistons aren't notched therefore I can't add bigger rockers or cam the engine is out and in pieces. I wanted to know what would be the best way to notch them? Also what year could this engine be and does it have forged pistons also? __________________ 67' Fastback-Supercharged 4.6 DOHC Cobra, T-56, 8.8 more to come. 67' Coupe-EFI, AOD, 8.8 90 Gt-Supercharged,MAF,TB,1.7's ripper, bassani x, 3.55's, 01' cobras, headers. 89'GT-Supercharged,Heads,Cam,Intake,TB,MAF,power pipe,headers,offroad exhaust,black bullits.

02-18-2002, 01:13 AM	#2
NO SLO PK Registered Member Join Date: Mar 1999 Location: Arcadia, CA, USA Posts: 731	Fostang, you can notch the pistons without disassembling the short block. I had this done on my old engine while it was still in the car. Iskendarian makes a special notching tool that uses a junk head as a guide. The Isky tool is just a grinding bit, in the diamteter of a valve relief. The tool fits inside the valve guide of the scrap head. Connect the shaft of the Isky tool to a 1/2" drill, and you've got your valve relief cutting tool. The piston has to be brought to TDC during the grinding. You might lose a gram or so of engine balance. The alternative seems to be disassembling the short block and sending the internals to a machine shop for cutting and balancing. Hope this helps. __________________ Russ L '91 LX - 331 w/ Procharger '03 Cobra Convertible - Pullied '94 Lightning '65 Mustang Coupe

02-19-2002, 11:50 AM	#4
Fostang Registered Member Join Date: Feb 2001 Location: Stockton, Ca Posts: 599	What would be the down fall of the engine not being balanced? __________________ 67' Fastback-Supercharged 4.6 DOHC Cobra, T-56, 8.8 more to come. 67' Coupe-EFI, AOD, 8.8 90 Gt-Supercharged,MAF,TB,1.7's ripper, bassani x, 3.55's, 01' cobras, headers. 89'GT-Supercharged,Heads,Cam,Intake,TB,MAF,power pipe,headers,offroad exhaust,black bullits.

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02-18-2002, 07:11 PM	#3
Nitrous Al Registered Member Join Date: May 2000 Location: Everett, MA Posts: 417	The pistons in that motor are cast, not forged. If you are going to tear it down to notch the pistons, buy a set of forged pistons for a 5.0 HO. The 5.0 HO pistons are also dished with the notches. I did a little research on the 5.0 HO conversion because I'm looking for an '86-'91 Crown Victoria/Grand Marquis as a daily driver. My girlfriend is tired of driving my truck so I'm going to get a car. A Crown Victoria or Grand Marquis with a modified 5.0 HO would be the perfect sleeper. The '94-'96 Impala SS only made 220 at the rear wheels. 300 hp at the wheels should scare a few Camaros and Imports out there and there's always nitrous.

02-19-2002, 12:50 PM	#5
DRASTiK Registered Member Join Date: May 2001 Location: Yuma, AZ Posts: 536	well depending on how off the balance is would determine the severity of the effects. Mostly it would shorten the life of the engine, and cause vibrations throughout the entire car. If it's way out of balance, it could be worse.