Allison vs. Merlin

mlenoch · **Posted:** Wed Jun 13, 2012 7:31 pm

Inspector wrote:
"Just love the 'I mean business' bass notes of an Indiana tractor motor-
remember, you can fly an ALLISON further than you can ship a MERLIN."

..........OK, I'll bite: What negative experience do you have with Merlins?....OR.....
..What positive experience do you have with Allisons?

VL

CWBuff · **Joined:** Tue Jul 19, 2005 1:14 am **Posts:** 854

I eagerly await this discussion. =)

Personally speaking, the only truly negative experience I've had concerning either of them was when I learned that my Dad's Uncle's barn burned, along with several cars and an Allison... I was in my early teens when I learned of this, but am still bummed about it to this day.

Fade to Black...

The Inspector · **Posted:** Wed Jun 13, 2012 8:34 pm

Vlado,
Two seasons of wrenching in Unlimited Hydroplane racing, where after the first season, the owner looked at our really cool stack of V-7 and V-5 MERLIN blocks behind the boatshop caused by breaking rods and decided to give ALLISONS a try, we broke exactly two ALLISONS in the next 12 race season, one when an oil line fitting failed and the other broke a blade rod. Punching a two bladed 13 X 23 steel prop into a Lake @ 16000 RPM's is like digging out a trowel sized piece of your driveway 16000 times a minute, want some loading on parts? The engine turns around 5000 RPM bolted to 3 to 1 step up gearbox turning the prop (bolted to a 3 inch diameter nickel/steel prop shaft 12 feet long) about 15-16 K a minute to make 7500 lbs of plywood go 185 MPH over the water riding on less than the area of a sheet of paper divided by 2 and one prop blade.
They are as easy to work on as a really big block Chevy, you need about two dozen wrenches, a few screwdrivers, a '16 oz persuader' or two and a couple different socket sets, and some pliers, not the Gold Card pass to the SNAP OFF tool truck for Whitworth or British Standard wrenches for two bolts or fittings @ $45.00 1969 dollars, or more each that you need once a race date (maybe) but can't live without, particularly if the wrench is in the shop in South Seattle and you really need it in Guntersville, AL now. You haven't lived until you've spent all night sitting in the pits at a cold after dark lakeside finger pier trying to make a temperamental pile of metal run after sneezing a couple of rods in qualifying, and you aren't on the Miss Budweiser team, or GALE, or EXIDE.
Just before the Unlims went turbine, one of the best financed teams actually cut up several blown up MERLINS and spliced together a -9 they named 'ACNE' because it was so ugly, it lasted one race weekend and grenaded again, but it won the three heats it was entered in and the final, and no one could compete with Bernie Little and the GRIFFON powered Miss Bud.
We'd build a couple motors over the off season, put one in the hull and the other in the back of the truck and down the road we'd go. Run the valve lash on Saturday, and put it in the water before the heats we were entered in, flip the starter switch and turn the mag switch and go racing usually with the characteristic stack fires common on ALLISONS in boats (no harm and the fans and TV cameras loved it!) we weren't the fastest but we all had a couple seasons of fun on the sponsors dime.

51fixer · **Posted:** Wed Jun 13, 2012 9:09 pm

I've noticed a distinctive lack of Allison's winning in the majority of Air Races over the last 50 years.
I'll also say that there are far fewer engines available to be flown today due to the anchors created by boats over the years.
None of these long stroke motors do well with the high rpms that the boat motors were run at along with the unloading/loading the powertrain goes through at times on water.
Merlins probably handled this worse but could make more boost than a tractor motor.
In aircraft the Griffon can't handle running the rpms that a Merlin can. The Red Baron P-51 ran around 3000 rpm and that wasn't healthy for the blower bearings IIRC.
The Spit with a Griffon the stock RPM is 2750 vs 3000 for the Merlin.

SaxMan · **Posted:** Wed Jun 13, 2012 10:11 pm

Didn't North American "return" to the Allison with the P-51H and the P-82? Surely, there must have been some advantage going to the Allison versus continued development of the Merlin. I'm hoping some "H" or Twin Mustang afficionados can fill in the blanks on this.

51fixer · **Posted:** Wed Jun 13, 2012 10:18 pm

SaxMan wrote:

Didn't North American "return" to the Allison with the P-51H and the P-82? Surely, there must have been some advantage going to the Allison versus continued development of the Merlin. I'm hoping some "H" or Twin Mustang afficionados can fill in the blanks on this.

H used the -9 Merlin.
1st P-82 used the Merlin.
The reverted to Allison's to avoid paying something like $5K a piece for licensing fees.
The late model Allison as used in the P-82 isn't much like the earlier version.
They had to make it perform like a Merlin. :wink:

The Inspector · **Posted:** Wed Jun 13, 2012 10:35 pm

But, after the war, there were stacks of ALLISONS that could be had brand new in the crate for less that $100.00 each so they tended to gravitate into racing boats because of pretty good torque and being dead reliable in a time when the rich guys who were boat racing (like Guy Lombardo, Horace Dodge or Stan Sayres) needed something with more grunt than you could wring out of the then high performance standard car engine, the 221 C.I. FORD Flathead or a DODGE flathead straight 8. The Jack Schaffer 'SUCH CRUST' ran a L/H and R/H pair of ALLISONS nose to nose with a system to couple them to the gearbox in the middle for the single prop. In 1962 the Miss U.S. running an ALLISON set the propeller driven water speed record that stood for over 25 years, @ 203.9 MPH.

It took a lot of boat shop engineering to make a MERLIN reliable enough to race in a boat (thanks to Mike Welch and the crew of the HAWAII KAI). Yeah, they all took a beating and the abuse wasn't good for their extended life, but Heck, 'I've got a warehouse full of brand new ones so who cares?'(MERLINS and ALLISONS). Given the single stage blowers with tiny impellers, they never were going to be as high output as the R/R. I'm just saying the Indiana tractor motors will live a longer life than the fragile blocked MERLINS because they weren't designed in the early 30's for that sort of high altitude application, or the inherent twisting moments in a lighter MERLIN block under extreme stresses (about 15000 ft was LOTS of altitude when the ALLISON came into service) remember that the ALLISONS Daddy was the Liberty V-12, they will take a great deal of abuse and not surrender the rods to pacify the torque gods, and they stayed in production for the same reasons that the P-40 did, it did a good enough job for 85+% of the applications it was used in and it was in production and proven (see the CONTINENTAL X-2100). If PACKARD hadn't been able to build the MERLIN for one reason or another (like going out of business in the depression, which they almost did) because Henry FORD told the Government to skip sand and pound gravel because he wasn't building any gol durned furrin engyne when asked to build MERLINS, the P-51 just might have remained a medium altitude 'ho-hum' ground attack aircraft with middling performance and if that had come to pass, maybe the British and the U.S. Army may have decided this new design wasn't needed and might have moved on to something else.
And. personally, I like the Basso sounds made by an ALLISON, so it's apples and oranges, Chevys and Fords, a matter of personal preferences isn't it?
And when the BUD ran GRIFFONS, Bernie made quite a show of pulling 14 race ready motors out of the engine truck (parked next to the machine shop truck/boat tow vehicle and near the 40 ft motorhome) and setting them on the dock side by side at every race, this is a guy who spent $5000.00 on towels for his new Miami based yacht 'The Eagle' back in the early 80's.

Richard Woods · **Posted:** Thu Jun 14, 2012 4:45 am

The Inspector wrote:

But, after the war, there were stacks of ALLISONS that could be had brand new in the crate for less that $100.00 each so they tended to gravitate into racing boats because of pretty good torque and being dead reliable in a time when the rich guys who were boat racing (like Guy Lombardo, Horace Dodge or Stan Sayres) needed something with more grunt than you could wring out of the then high performance standard car engine, the 221 C.I. FORD Flathead or a DODGE flathead straight 8. The Jack Schaffer 'SUCH CRUST' ran a L/H and R/H pair of ALLISONS nose to nose with a system to couple them to the gearbox in the middle for the single prop. In 1962 the Miss U.S. running an ALLISON set the propeller driven water speed record that stood for over 25 years, @ 203.9 MPH.

It took a lot of boat shop engineering to make a MERLIN reliable enough to race in a boat (thanks to Mike Welch and the crew of the HAWAII KAI). Yeah, they all took a beating and the abuse wasn't good for their extended life, but Heck, 'I've got a warehouse full of brand new ones so who cares?'(MERLINS and ALLISONS). Given the single stage blowers with tiny impellers, they never were going to be as high output as the R/R. I'm just saying the Indiana tractor motors will live a longer life than the fragile blocked MERLINS because they weren't designed in the early 30's for that sort of high altitude application, or the inherent twisting moments in a lighter MERLIN block under extreme stresses (about 15000 ft was LOTS of altitude when the ALLISON came into service) remember that the ALLISONS Daddy was the Liberty V-12, they will take a great deal of abuse and not surrender the rods to pacify the torque gods, and they stayed in production for the same reasons that the P-40 did, it did a good enough job for 85+% of the applications it was used in and it was in production and proven (see the CONTINENTAL X-2100). If PACKARD hadn't been able to build the MERLIN for one reason or another (like going out of business in the depression, which they almost did) because Henry FORD told the Government to skip sand and pound gravel because he wasn't building any gol durned furrin engyne when asked to build MERLINS, the P-51 just might have remained a medium altitude 'ho-hum' ground attack aircraft with middling performance and if that had come to pass, maybe the British and the U.S. Army may have decided this new design wasn't needed and might have moved on to something else.
And. personally, I like the Basso sounds made by an ALLISON, so it's apples and oranges, Chevys and Fords, a matter of personal preferences isn't it?
And when the BUD ran GRIFFONS, Bernie made quite a show of pulling 14 race ready motors out of the engine truck (parked next to the machine shop truck/boat tow vehicle and near the 40 ft motorhome) and setting them on the dock side by side at every race, this is a guy who spent $5000.00 on towels for his new Miami based yacht 'The Eagle' back in the early 80's.

Not much of this has any bearing on "you can fly an ALLISON further than you can ship a MERLIN." it just proves they don't work in hydroplanes. But that's what happens when you push an aero engine to its limits and beyond in a task it wasn't really designed for.

Ignoring usage in a hydroplane, the Merlin wasn't completely useless on water, it was successfully used in British motor torpedo launches from around 1938 in a marine version. Another Merlin derivative - the unsupercharged Meteor - was quite happy powering tanks, and still in use during the first Gulf War in the Centurion AVRE used by the British Army. And if the tank broke, it would be collected by a transporter that was likely to be powered by another Rolls Royce Meteor.

As for the P-51 - Rolls Royce at Hucknall built the first Merlin powered version in 1942 and Packard had already been producing Merlins since late 1941 for use in Lancasters and the like. The mass production Merlin powered P-51 didn't arrive until 1943, so Ford really didn't play too big a part in whether it was going to be a reality or not; the engines were already available. There was an order placed for the Rolls Royce variant of the Mustang, but it was cancelled when the P-51B/C became available.

My personal engine choice would be the Griffon... but I'm biased.

Regards,

Rich

levier · **Posted:** Thu Jun 14, 2012 6:51 am

Vlado,

You've awakened the creative writing spirit here with marvelous effect, I love it!

Brian Silcox

http://www.flightof2photography.com

51fixer · **Posted:** Thu Jun 14, 2012 7:21 am

Rolls Royce Heritage Trust has published some great books covering the Merlin development and its design.
Biggest factor on producing more power was the development and production of higher octane fuels. Most was shipped from the US.
This sparked continued development of the engine.

airnutz · **Posted:** Thu Jun 14, 2012 8:42 am

As to the wholesale post war use of the Merlin and Allison's...agriculture consumed some of them around these parts. One of my uncles managed commercial farms in the Rio Grande Valley...they bought the surplus engines dirt cheap to power irrigation pumps. Most of the time they ran them near full throttle with typical farmer frugal maintenance routine until they died. Junk it, break another out of a crate and back to bidness. :shock:

Ask Dave Homewood about the Valley of the Merlin's in New Zealand where, IIRC, they bought surplus propellered Merlin's which they fired-up during an imminent frost conditions in the produce groves in order to save them from damage. That must have been a glorius sound if you found the "sweet spot" in the valley to hear that!!!

The Inspector · **Posted:** Thu Jun 14, 2012 9:00 am

Richard Woods wrote:

The Inspector wrote:

But, after the war, there were stacks of ALLISONS that could be had brand new in the crate for less that $100.00 each so they tended to gravitate into racing boats because of pretty good torque and being dead reliable in a time when the rich guys who were boat racing (like Guy Lombardo, Horace Dodge or Stan Sayres) needed something with more grunt than you could wring out of the then high performance standard car engine, the 221 C.I. FORD Flathead or a DODGE flathead straight 8. The Jack Schaffer 'SUCH CRUST' ran a L/H and R/H pair of ALLISONS nose to nose with a system to couple them to the gearbox in the middle for the single prop. In 1962 the Miss U.S. running an ALLISON set the propeller driven water speed record that stood for over 25 years, @ 203.9 MPH.

It took a lot of boat shop engineering to make a MERLIN reliable enough to race in a boat (thanks to Mike Welch and the crew of the HAWAII KAI). Yeah, they all took a beating and the abuse wasn't good for their extended life, but Heck, 'I've got a warehouse full of brand new ones so who cares?'(MERLINS and ALLISONS). Given the single stage blowers with tiny impellers, they never were going to be as high output as the R/R. I'm just saying the Indiana tractor motors will live a longer life than the fragile blocked MERLINS because they weren't designed in the early 30's for that sort of high altitude application, or the inherent twisting moments in a lighter MERLIN block under extreme stresses (about 15000 ft was LOTS of altitude when the ALLISON came into service) remember that the ALLISONS Daddy was the Liberty V-12, they will take a great deal of abuse and not surrender the rods to pacify the torque gods, and they stayed in production for the same reasons that the P-40 did, it did a good enough job for 85+% of the applications it was used in and it was in production and proven (see the CONTINENTAL X-2100). If PACKARD hadn't been able to build the MERLIN for one reason or another (like going out of business in the depression, which they almost did) because Henry FORD told the Government to skip sand and pound gravel because he wasn't building any gol durned furrin engyne when asked to build MERLINS, the P-51 just might have remained a medium altitude 'ho-hum' ground attack aircraft with middling performance and if that had come to pass, maybe the British and the U.S. Army may have decided this new design wasn't needed and might have moved on to something else.
And. personally, I like the Basso sounds made by an ALLISON, so it's apples and oranges, Chevys and Fords, a matter of personal preferences isn't it?
And when the BUD ran GRIFFONS, Bernie made quite a show of pulling 14 race ready motors out of the engine truck (parked next to the machine shop truck/boat tow vehicle and near the 40 ft motorhome) and setting them on the dock side by side at every race, this is a guy who spent $5000.00 on towels for his new Miami based yacht 'The Eagle' back in the early 80's.

Not much of this has any bearing on "you can fly an ALLISON further than you can ship a MERLIN." it just proves they don't work in hydroplanes. But that's what happens when you push an aero engine to its limits and beyond in a task it wasn't really designed for.

Ignoring usage in a hydroplane, the Merlin wasn't completely useless on water, it was successfully used in British motor torpedo launches from around 1938 in a marine version. Another Merlin derivative - the unsupercharged Meteor - was quite happy powering tanks, and still in use during the first Gulf War in the Centurion AVRE used by the British Army. And if the tank broke, it would be collected by a transporter that was likely to be powered by another Rolls Royce Meteor.

As for the P-51 - Rolls Royce at Hucknall built the first Merlin powered version in 1942 and Packard had already been producing Merlins since late 1941 for use in Lancasters and the like. The mass production Merlin powered P-51 didn't arrive until 1943, so Ford really didn't play too big a part in whether it was going to be a reality or not; the engines were already available. There was an order placed for the Rolls Royce variant of the Mustang, but it was cancelled when the P-51B/C became available.

My personal engine choice would be the Griffon... but I'm biased.

Regards,

Rich

Ford was approached BEFORE PACKARD about building the engines, IF PACKARD had gone out of business in the late 30's when the market for their huge luxury cars had all but dried up, then there might never have been anyone to build the engines as GM was gearing up for dozens of other projects and may not have had the facilities or manpower to accomplish the task and every other auto manufacturer except poor tiny American Bantam were all up to their necks in contracts, thereby making the A-36 APACHE just a newer version of the already existing P-40. My intent, if you take time to read it, was to point out the reliabilty of one engine over another in an extreme application. And, I'm fairly well versed in who first installed a MERLIN in a MUSTANG airframe.
It does warm my heart to see that one, simple jesting throwaway line can get so many folks foaming at the mouth, and it isn't even my line to start with, someone else who posts (or posted ) here said it first, I just borrowed it because it's sort of funny. GEEZ get a lifestyle willya-

ktst97 · **Posted:** Thu Jun 14, 2012 9:27 am

America's two top aces, Bong and McGuire, were Allison powered.

But that bit of trivia doesn't relate to this interesting discussion worth a hoot.

Speedy · **Posted:** Thu Jun 14, 2012 10:08 am

On multiple occasions I was on the receving end of the "Bradley, a Merlin in a box is faster than an Allison in a plane" lecture from the late Ralph Payne. That same sentiment was echoed by Big Dave Z endless times as well, though I believe his name of choice for the Merlin was a "hot water toilet".

Mark Allen M · **Joined:** Fri Feb 03, 2012 1:48 pm **Posts:** 7812

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