To clarify here is the site that tells the differances between a Boss 351 and a 4V 351.
http://www.boss351.org/main.htm
I thought about trying to find a Boss 351 when I replaced engines this year but wasn't able to find one.
Original Post
Replies sorted oldest to newest
DeTom,
The Boss 351 isn't all that "special". It had a few heavy duty parts, adjustable valvetrain & a mild solid lifter cam. It had the same spread bore Autolite carb as the '72 through'74 Cobra Jet Clevelands. The heads were closed chamber, big port & big valve heads, identical to the heads on the '70 & '71 Panteras, except for the adjustable valve train. With closed chamber heads and a small pop up dome piston, the compression ratio was about 10 to 1, although it was advertised as being higher.
Unless you are racing for money and need every bit of horsepower you can wring out of the motor, I wouldn't advise using a solid lifter cam in a Pantera, due to the difficulty in adjusting the valves. Its a hot & messy job even in a front engine car like a Mustang.
Valve train technology has advanced significantly in the last decade, and today you can make more power with a hydraulic lifter roller cam. Add a 750 Holley, Blue Thunder intake, modern ignition and good exhaust system, and you are easily in the 400 bhp range. Call it a 21st Century Boss.
your friend on the PIBB, George
The Boss 351 isn't all that "special". It had a few heavy duty parts, adjustable valvetrain & a mild solid lifter cam. It had the same spread bore Autolite carb as the '72 through'74 Cobra Jet Clevelands. The heads were closed chamber, big port & big valve heads, identical to the heads on the '70 & '71 Panteras, except for the adjustable valve train. With closed chamber heads and a small pop up dome piston, the compression ratio was about 10 to 1, although it was advertised as being higher.
Unless you are racing for money and need every bit of horsepower you can wring out of the motor, I wouldn't advise using a solid lifter cam in a Pantera, due to the difficulty in adjusting the valves. Its a hot & messy job even in a front engine car like a Mustang.
Valve train technology has advanced significantly in the last decade, and today you can make more power with a hydraulic lifter roller cam. Add a 750 Holley, Blue Thunder intake, modern ignition and good exhaust system, and you are easily in the 400 bhp range. Call it a 21st Century Boss.
your friend on the PIBB, George
Thanks George. Yeah I know there are guys here making way more power than that in there cars. I kind of wonder why Ford or DeTomaso didn't think of making a Boss Pantera though. Back in those days it would have been quite the set-up. The link I posted said this thing let a 3700 pound car run in the thirteens. Kind of makes you wonder what it would have done in a 3000 pound Pantera.
I kept my high compression heads from my old motor, the markings on them indicated they were made in 1970. So maybe I should turn it into a Boss motor after the three year warrenty is up and make up some BS story about it being a "SPecial, one off, one of a kind Boss 351 Pantera" and sell my car for a zillion bucks????
I kept my high compression heads from my old motor, the markings on them indicated they were made in 1970. So maybe I should turn it into a Boss motor after the three year warrenty is up and make up some BS story about it being a "SPecial, one off, one of a kind Boss 351 Pantera" and sell my car for a zillion bucks????
DeTom,
yeah, the '71 Boss 351 'stang had the reputation for being the fastest accelerating Mustang "off the show room floor" until the 320 bhp cobra Mustang came along in the '90s. This was not because it was the most powerful Mustang, but because it overwhelmed the stock chassis less than the big block Mustangs, less tire spin equated to more acceleration. The Boss 351 accelerated to 60 mph in 5.8 seconds and pulled the 1/4 mile in 13.8 seconds. The engine was rated at 330 bhp, and the car had a 3.91 rear gear ratio, traction lock & a 4 speed top loader, rolling on F60 x 15 polyglass tires. The engine had a 6100 rpm rev limiter, but Ford issued a bulletin early on explaining how to disable it.
The Pantera could have used the extra 50 bhp of the motor, but what a pain it would have been to adjust the valves about every 6000 miles.
That same year, in Australia, a similar (identical?) motor was installed in the Falcon GT HO phase III one of Australia's most famous muscle cars. It came standard with 3.25 gearing and a 4 speed toploader, did zero to 60 in about 6.4 seconds, the quarter mile in 14.4 seconds and had a top speed of 142 mph (all this from memory, so forgive me if I err). It had the distinction of being the worlds fastest (top speed) 4 door sedan that year. Estimates of the output for that engine are 375 to 400 bhp.
None of my Australian contacts have ever been able to tell me in what way the GT HO phase III motor differed from the Boss 351 motor, if any.
your friend on the PIBB, George
yeah, the '71 Boss 351 'stang had the reputation for being the fastest accelerating Mustang "off the show room floor" until the 320 bhp cobra Mustang came along in the '90s. This was not because it was the most powerful Mustang, but because it overwhelmed the stock chassis less than the big block Mustangs, less tire spin equated to more acceleration. The Boss 351 accelerated to 60 mph in 5.8 seconds and pulled the 1/4 mile in 13.8 seconds. The engine was rated at 330 bhp, and the car had a 3.91 rear gear ratio, traction lock & a 4 speed top loader, rolling on F60 x 15 polyglass tires. The engine had a 6100 rpm rev limiter, but Ford issued a bulletin early on explaining how to disable it.
The Pantera could have used the extra 50 bhp of the motor, but what a pain it would have been to adjust the valves about every 6000 miles.
That same year, in Australia, a similar (identical?) motor was installed in the Falcon GT HO phase III one of Australia's most famous muscle cars. It came standard with 3.25 gearing and a 4 speed toploader, did zero to 60 in about 6.4 seconds, the quarter mile in 14.4 seconds and had a top speed of 142 mph (all this from memory, so forgive me if I err). It had the distinction of being the worlds fastest (top speed) 4 door sedan that year. Estimates of the output for that engine are 375 to 400 bhp.
None of my Australian contacts have ever been able to tell me in what way the GT HO phase III motor differed from the Boss 351 motor, if any.
your friend on the PIBB, George
I think an article I read said the Boss 351 was actualy more like 375 horsepower but they published low numbers for insurance idustry. High insurance rates where putting the squeeze on muscle cars too. Anyway if I do decide to make a faux Boss motor I would not use a solid lifter cam. Not when hydraulic rollers are performing so well. And my understanding is that a Cleveland can use them if you mill slots for them in the block and use the right length lifters. I bet the future owner would actually appreciate not having to know what valve lash meant.
Now all I have to do is find some Boss nameplates and I am all set. I will have to fabricate some fascinating story too like maybe how Alexandro did this for his own personal car or something.
Now all I have to do is find some Boss nameplates and I am all set. I will have to fabricate some fascinating story too like maybe how Alexandro did this for his own personal car or something.
DeTom,
I used Crane hydraulic roller lifters in the 351C buildup I did for my '74 Pantera. NO modifications were necessary to use them in the block.
The lifters are linked together in pairs with a slotted tie-bar. This is to prevent them from 'spinning' in their bores, as regular lifters do (to promote even wear).
They are good to 7000+ RPM, and cost about $400. To me, they were totally worth it!
Michael
I used Crane hydraulic roller lifters in the 351C buildup I did for my '74 Pantera. NO modifications were necessary to use them in the block.
The lifters are linked together in pairs with a slotted tie-bar. This is to prevent them from 'spinning' in their bores, as regular lifters do (to promote even wear).
They are good to 7000+ RPM, and cost about $400. To me, they were totally worth it!
Michael
Michael & DeTom,
The Crane lifters are the hot tip! Expensive, but choice quality stuff. For the budget concious, Competition Cams runs Ford type hydraulic lifters, which can be found at the wrecking yard, or purchased on e-bay at reasonable prices.
Now DeTom, a roller cam installation goes like this. The cam has higher valve lift & more agressive ramps, plus it is machined out of billet steel. The iron distributor gear won't like the billet steel gear it meshes with on the cam, so the distributor drive gear must be replaced with a steel gear. (Competition Cams uses iron cores for its hydraulic roller cams) The agressive, high lift lobes of the cam require stiffer valve springs. Those stiffer valve springs require beefier spring retainers & locks, plus single groove, one piece stainless steel valves. The stiffer springs & higher valve lifts will also wear and or break your stock rocker arms, so you'll need to spring for a set of "good" (not inexpensive) roller rocker arms. Finally, those springs will flex the stock size 5/16" push rods, so you'll need to run 3/8" push rods.
In other words, the valve train is an engineered system, you can't agressively hot rod just one part of it, you must upgrade the entire system.
Or, as I always tell my friends, speed cost money, how fast do you want to go?
Your friend on the PIBB, George
The Crane lifters are the hot tip! Expensive, but choice quality stuff. For the budget concious, Competition Cams runs Ford type hydraulic lifters, which can be found at the wrecking yard, or purchased on e-bay at reasonable prices.
Now DeTom, a roller cam installation goes like this. The cam has higher valve lift & more agressive ramps, plus it is machined out of billet steel. The iron distributor gear won't like the billet steel gear it meshes with on the cam, so the distributor drive gear must be replaced with a steel gear. (Competition Cams uses iron cores for its hydraulic roller cams) The agressive, high lift lobes of the cam require stiffer valve springs. Those stiffer valve springs require beefier spring retainers & locks, plus single groove, one piece stainless steel valves. The stiffer springs & higher valve lifts will also wear and or break your stock rocker arms, so you'll need to spring for a set of "good" (not inexpensive) roller rocker arms. Finally, those springs will flex the stock size 5/16" push rods, so you'll need to run 3/8" push rods.
In other words, the valve train is an engineered system, you can't agressively hot rod just one part of it, you must upgrade the entire system.
Or, as I always tell my friends, speed cost money, how fast do you want to go?
Your friend on the PIBB, George
Thanks for all the great info. I have been reading about all these guys breaking their stuff because of these super heavy duty valve springs they have been using. The reason they need these springs is to return the valves sooner right?? Has anybody thought to try to make a lighter weight valve so they won't have to use such heavy force load springs?? It would sure seem to me it would save a lot of wear and tear on the motor that way. How about Titanium??? It is light but pleanty strong. Has anyone made titanium valves????
Yes, titanium valves were available in Cleveland sizes and are regularly used by racing teams. They don't negate the need for stiff valve springs, but they allow more rpm. As you might imagine, they are expensive. They are also tough on valve seats. I do not think they are readily available in Cleveland sizes any longer, but I do see them come up occasionally on e-bay & at swap meets. Modern Ford race heads use valves with smaller heads and in some applications longer stems, the Cleveland size stuff just isn't in demand by race teams any longer.
Stainless steel is the best material for most street engines. The caveat is to make sure the valve is a "one piece" design, if so, the manufacturer will specify "one piece" in their description of the valve. Two piece valves are known to come apart under hard use, and engines really don't tolerate a loose valve head banging around inside a cylinder very well!
Your friend on the PIBB, George
Stainless steel is the best material for most street engines. The caveat is to make sure the valve is a "one piece" design, if so, the manufacturer will specify "one piece" in their description of the valve. Two piece valves are known to come apart under hard use, and engines really don't tolerate a loose valve head banging around inside a cylinder very well!
Your friend on the PIBB, George
...I've put 900 miles, so far, on the 'Boss 358' (.030 Over) I just finished building...
Thanks George. You are so patient. I appreciate it. Now I am thinking I will leave well enough alone. Why do things to your motor that will put it under even more stress?? I think I will just stay with my CJ spec cam.
quote:Originally posted by MARLIN JACK:
...I've put 900 miles, so far, on the 'Boss 358' (.030 Over) I just finished building...
Marlin, is it really a Boss or is it a hotted up windsor?? Did you read the web site I linked to?? Do you like your Boss?? Does it have high compression??
I have 500 miles on my CJ spec motor and next weekend I am changing out the break in oil. Pushbutton warned me not to switch to syntech too soon so for the first oil change I am going to use good old straight weitght 50 just like what is recommended in the book. Next oil change after that I am going with that new mobile one, go forever oil that they been advertiseing on TV.
DeTom, please change your oil every 5000 miles or once per year, whichever comes first, even with synthetic. The notion that you can go farther between oil changes with synthetic is, to put it bluntly, crap!
Its best to change your oil at the end of each driving season, so your bearings sit in unpolluted oil during the winter, plus start the engine up once per week during the winter to prevent the build up of moisture.
For some reason, oil is a controversial subject among auto enthusiasts, so I may have just opened a can of worms! LOL
Your controversial friend on the PIBB, George
Its best to change your oil at the end of each driving season, so your bearings sit in unpolluted oil during the winter, plus start the engine up once per week during the winter to prevent the build up of moisture.
For some reason, oil is a controversial subject among auto enthusiasts, so I may have just opened a can of worms! LOL
Your controversial friend on the PIBB, George
That's OK George, I really like you so no problem bringing up controversy, I don't mind. I actually drive my car all year round. I like to take it out when it is cooler because one thing the car does really well is makes a lot of heat. So I will drive my car on a cold winter day, just as long as there is zero percipitation. I have the same rule in the summer too. Absoluetly zero water. I have even turned around in a road where I would have had to go through a puddle. My kitty hates water. But as far as oil goes, I only drive (normaly) about 200 miles a year. I think changing oil every 200 miles is kinda silly. I plan on driving it more, and I have had to try really hard just getting 500 miles on it this year. I doubt that I will get much more than 750 miles total this year.
I guess I am not a very good Pantera daddy or I would drive it more.
I guess I am not a very good Pantera daddy or I would drive it more.
George, you always have good an interesting info about engines. I was curiouse, what is you background? Did you work on a lot of cars in your youth? Do you research most of it or (and I had to ask) did you just sleep in a Holiday Inn last night? Sorry, had to say that.
Gary
Gary
My background: 
I was born a poor black child... oh, never mind, that's Steve Martin's line. LOL
I was born with a wrench in my hand (mom didn't appreciate that!
LOL).
But once my wrench & I made it into the world, I began applying that wrench on Triumph motorcycles by the age of 9, then Hondas, then assorted European bikes, then domestic cars. We were in the midst of the '60s, the muscle car era, and I grew up in the south bay area of southern California, hot rod central of the world back then (Torrance, Redondo Beach, Long Beach). Lyons Drag Strip & Ascot Park were both 15 minutes from my home, I could hear them racing at night from my house.
By the time I was a teenager freinds & family started referring work to me and I always had more work than I needed. Cars and motorcycles; maintenance, repairs and modifying. I did the work on evenings & weekends, never as a full time job, I never considered it a business, but it was a good source of pocket money. My clients were friends, neighbors and family; or friends of friends, friends of neighbors and friends of family. Never strangers. I worked first out of my parents garage, and later out of my own. I was the unofficial pit crew for many of my friends who raced their motorcycles or cars. Chassis, drive trains and suspensions where my interest, I've only done a small amount of body work, I prefer to leave that work to the folks who have the "feel" for it. It was a "boom" time for me when California first instituted smog inspections in the late '70s. I had to deal with a lot of those types of problems in that period and throughout the '80s as well. Those issues declined as fuel injection became standard equipment. Hot rodding was big in the '80s, and that's when the Mustang restoration craze took off too.
Because the 351C was the powerplant in my dream car (the Pantera) I made it my specialty, I was Mr Mustang to many folks in the Long Beach area for that reason. I've built about 18 performance engines in my life, not just Clevelands either; and I've worked on a couple of hundred of automobiles. I would farm out my engine machine work, head porting etc to pro engine builders, and always listened to their advice, I learned a lot from them.
I have an "engineers" attitude regarding mechanical things, rather than the "folksy" back yard mechanic type attitude. I have always found reading technical manuals and in depth engineering articles my favorite type of reading, I'm consumed with curiosity to understand why things are engineered the way they are. So you could say I've been "researching" this stuff my whole life.
All in all, I'm just another gear head.
your greasy friend on the PIBB, George
I was born a poor black child... oh, never mind, that's Steve Martin's line. LOL
I was born with a wrench in my hand (mom didn't appreciate that!
LOL). But once my wrench & I made it into the world, I began applying that wrench on Triumph motorcycles by the age of 9, then Hondas, then assorted European bikes, then domestic cars. We were in the midst of the '60s, the muscle car era, and I grew up in the south bay area of southern California, hot rod central of the world back then (Torrance, Redondo Beach, Long Beach). Lyons Drag Strip & Ascot Park were both 15 minutes from my home, I could hear them racing at night from my house.
By the time I was a teenager freinds & family started referring work to me and I always had more work than I needed. Cars and motorcycles; maintenance, repairs and modifying. I did the work on evenings & weekends, never as a full time job, I never considered it a business, but it was a good source of pocket money. My clients were friends, neighbors and family; or friends of friends, friends of neighbors and friends of family. Never strangers. I worked first out of my parents garage, and later out of my own. I was the unofficial pit crew for many of my friends who raced their motorcycles or cars. Chassis, drive trains and suspensions where my interest, I've only done a small amount of body work, I prefer to leave that work to the folks who have the "feel" for it. It was a "boom" time for me when California first instituted smog inspections in the late '70s. I had to deal with a lot of those types of problems in that period and throughout the '80s as well. Those issues declined as fuel injection became standard equipment. Hot rodding was big in the '80s, and that's when the Mustang restoration craze took off too.
Because the 351C was the powerplant in my dream car (the Pantera) I made it my specialty, I was Mr Mustang to many folks in the Long Beach area for that reason. I've built about 18 performance engines in my life, not just Clevelands either; and I've worked on a couple of hundred of automobiles. I would farm out my engine machine work, head porting etc to pro engine builders, and always listened to their advice, I learned a lot from them.
I have an "engineers" attitude regarding mechanical things, rather than the "folksy" back yard mechanic type attitude. I have always found reading technical manuals and in depth engineering articles my favorite type of reading, I'm consumed with curiosity to understand why things are engineered the way they are. So you could say I've been "researching" this stuff my whole life.
All in all, I'm just another gear head.
your greasy friend on the PIBB, George
Thanks George, I was curiouse what the background of your knowlege was. It's always intersting to see where people learn their "Stuff"
Gary
Gary
Detom, can you drop me an email.
carrera_c4@yahoo.com
Thanks
Steve
carrera_c4@yahoo.com
Thanks
Steve