5.0, H.o ?????

Quick Pony · 12-08-2002, 06:16 PM

What does H.O. mean? Are all 5.0's H.O.'s? If not, how do you know if you have an H.O. ?

Thanks
Larry

TwiLighTBluEGT · 12-08-2002, 06:50 PM

H.O. means "High Output." Not all 5.0's were H.O., but all the ones in the mustangs were.

crazypete · 12-08-2002, 07:06 PM

It's been a while but I think the intake cover plate has 302 HO stamped on it.

84LX89GT · 12-08-2002, 07:57 PM

Like already mentioned, the 5.0L HO stands for 5 liter, high output. They're distinguished by factory headers from '86+, 5.0L HO intake cover plaque, and a few internal changes from the non high output engine.

BLACK85GT · 12-08-2002, 10:14 PM

The H.O. has roller cam and lifters. The H.O. has a different firing order than the non h.o. The h.o. firing order is same as the 351W firing order. The firing orders are as follows:
H.O. 302 and 351W: 1-3-7-2-6-5-4-8
std. 302 1-5-4-2-6-3-7-8

Quick Pony · 12-08-2002, 10:21 PM

Thanks guys for the information.

Larry

rustang girl · 12-16-2002, 02:04 PM

Are 5.0 HO engines good engines?

(I have an '87 5.0 H.O. engine in my '66 Mustang.)

Falcons Talon · 12-16-2002, 02:14 PM

Quote:

Originally posted by BLACK85GT
The H.O. has roller cam and lifters. The H.O. has a different firing order than the non h.o. The h.o. firing order is same as the 351W firing order. The firing orders are as follows:
H.O. 302 and 351W: 1-3-7-2-6-5-4-8
std. 302 1-5-4-2-6-3-7-8

85 was first year w/stock roller lifter. I had an '84 5.0 HO.

PKRWUD · 12-16-2002, 02:27 PM

The 5.0 HO first came out in the 1982 Mustangs. In 1985, they started using roller cams and "factory headers". In 1986 they stopped using carbs, and went to speed density SEFI. Also, from 1986 on, all 5.0's installed in passenger cars used the exact same block as the HO. While the HO's came with a roller cam, most of the others came with a flat cam, but could accept a roller cam. In 1988, the Mustangs sold in California switched from speed density to Mass Air. In 1989, all of the Mustangs had Mass Air. Also, the truck 5.0's all used the same block now too, meaning that even though they came with a flat cam, they would accept a roller cam. In 1993, they switched from forged pistons to hypereutectic (sp?) pistons.

All of the 5.0 HO's, as mentioned, used the 351W firing order.

Take care,
~Chris

PKRWUD · 12-16-2002, 02:28 PM

Quote:

Originally posted by Falcons Talon
85 was first year w/stock roller lifter. I had an '84 5.0 HO.

lol, I need to learn how to type faster. Didn't mean to duplicate that info.

Take care,
~Chris

12-08-2002, 06:16 PM	#1
Quick Pony Registered Member Join Date: Nov 2002 Location: Woodstock, Georgia Posts: 3	5.0, H.o ????? What does H.O. mean? Are all 5.0's H.O.'s? If not, how do you know if you have an H.O. ? Thanks Larry

12-08-2002, 06:50 PM	#2
TwiLighTBluEGT Registered Member Join Date: Jun 2002 Location: Massachusetts Posts: 157	H.O. means "High Output." Not all 5.0's were H.O., but all the ones in the mustangs were. __________________ 1991 Mustang GT Conv: 58,000 original miles, 2nd owner. Engine: FMS 65mm tb/spacer, C&L 73mm maf, MAC cai. Drivetrain: Built AOD w/ Edge 2800rpm lockup converter, hardened 3-4 inner shaft, Trans-Go shift kit, B&M supercooler, FMS 3.73 gears & aluminum d/s, rebuilt traction lock. Exhaust: BBK unequal length shorty headers, BBK o/r h-pipe, Flowmaster 2 chamber mufflers. Chassis/suspension/brakes: Kenny Brown supersubs. The rest is stock.

12-08-2002, 07:06 PM	#3
crazypete Registered Member Join Date: Sep 2002 Location: Boston Posts: 592	It's been a while but I think the intake cover plate has 302 HO stamped on it. __________________ 91 GT Carb conversion, holley 600 double pumper, edelbrock performer intake, FMS "C" drop springs, march 1000 underdrive pullies, crane 1.7 roller rockers, GT-40P headers, bassani x pipe, american thunder catback, FMS 4.56's, msd aL6, trunkmount battery, A/C eliminator kit, 3000 stall tci streetfighter, AOD with transgo kit, A+ servo, 300M hardened lockup shaft, kevlar bands and 28,000 gvw trans cooler, 3 core radiator, 300 lbs stripped with a full interior

12-08-2002, 07:57 PM	#4
84LX89GT Mustangs Join Date: Jul 2000 Posts: 1,938	Like already mentioned, the 5.0L HO stands for 5 liter, high output. They're distinguished by factory headers from '86+, 5.0L HO intake cover plaque, and a few internal changes from the non high output engine. __________________ 2005 Suzuki Hayabusa GSX1300-R 1980 Ford Thunderbird - 255 V8 ported heads, 5.0L ported stock headers, O.R. H-pipe and Flowmaster 2-chambers, dual roller timing chain hi-po Mack Truck hood emblem 1985 Mustang GT 5.0L T5, F-303, GT40p, headers, off-road h, flowmasters, MSD stuff, etc. Sold 02/06/04 1989 Mustang GT ET: 13.304@102.29 mph (5-24-03) Sold - 1998 Mustang Cobra coupe, 1/4 mile - street tires: 13.843@103.41 (bone stock)

12-08-2002, 10:14 PM	#5
BLACK85GT Registered Member Join Date: May 2002 Location: Tampa,FLORIDA Posts: 340	The H.O. has roller cam and lifters. The H.O. has a different firing order than the non h.o. The h.o. firing order is same as the 351W firing order. The firing orders are as follows: H.O. 302 and 351W: 1-3-7-2-6-5-4-8 std. 302 1-5-4-2-6-3-7-8 __________________ 5.0, Holley heads, 1.7 Scorp Rockers, Stealth intake, Holley 600 carb, Holley Mech. Fuel pump, MSD 6Digital, MSD distributor, Hotchkis upper/lower rear control arms, FMS B Springs, 3:73 (8.8) rear. Production # 9,377

12-08-2002, 10:21 PM	#6
Quick Pony Registered Member Join Date: Nov 2002 Location: Woodstock, Georgia Posts: 3	Thanks guys for the information. Larry

12-16-2002, 02:04 PM	#7
rustang girl Registered Member Join Date: Jul 2002 Location: LA, or Bakersfield, CA Posts: 273	Are 5.0 HO engines good engines? (I have an '87 5.0 H.O. engine in my '66 Mustang.) __________________ Heidi 22/F/Cali. 1966 Mustang Coupe Ricer Hater's Club- member # 15 http://ricehatersclub.com/ http://MechaPS.com/ Last edited by rustang girl; 12-16-2002 at 02:21 PM..

12-16-2002, 02:27 PM	#9
PKRWUD Junior Member Join Date: Mar 1999 Location: Ventura, California Posts: 8,981	The 5.0 HO first came out in the 1982 Mustangs. In 1985, they started using roller cams and "factory headers". In 1986 they stopped using carbs, and went to speed density SEFI. Also, from 1986 on, all 5.0's installed in passenger cars used the exact same block as the HO. While the HO's came with a roller cam, most of the others came with a flat cam, but could accept a roller cam. In 1988, the Mustangs sold in California switched from speed density to Mass Air. In 1989, all of the Mustangs had Mass Air. Also, the truck 5.0's all used the same block now too, meaning that even though they came with a flat cam, they would accept a roller cam. In 1993, they switched from forged pistons to hypereutectic (sp?) pistons. All of the 5.0 HO's, as mentioned, used the 351W firing order. Take care, ~Chris __________________ Webmaster: Rice Haters Club Jim Porter Racing Peckerwoods Pit Stop Support Your Local RED & WHITE!