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Getting more horse power from a Healey 100

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if i was trying to bring my second v8 conversion to life i would buy this one....but i have a very nice v8 bj7 and will soon have a very nice v8 bn6. both were conversions before i purchased them at different times!!
 
drambuie said:
. Wow.. $50,000 spent on some motor upgrades? And the result is 115 Hp on the dyno..
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Whether that's an accurate figure of the cost of the motor or not, even if you cut it in half, an engine swap is likely to give you more performance per dollar. Most of the discussion here has been about V8 swaps, but there are an awful lot of high-output aluminum twin-cam fours, some supercharged or turbocharged, that would probably be big fun in a 100 with no weight penalty over the front wheels. Think Hunter twin cam head:

hh4.jpg



https://www.acmefluid.com.au/larry/hhimages.html
 
HealeyRick said:
......but there are an awful lot of high-output aluminum twin-cam fours, some supercharged or turbocharged, that would probably be big fun in a 100 with no weight penalty over the front wheels. Think Hunter twin cam head:

hh4.jpg
Click to expand...

Rick, you stole both of my ideas! I've been dreaming about the Hunter head since first reading about it in the early 70's. Probably the only way to modify a 100 and increase its value substantially.
The idea of a modern EFI, turbo twin cam 4 has also crossed my mind, and that would likely reduce front end weight a fair bit.
 
I will first say it is your car and you can do what you want with it. I don't really agree about the four cylinder cars being so underpowered as to be dangerous. A stock four is as quick as an early six and simply going to M spec gets you in the same ballpark as a BJ8 ( in performance, not total HP). Yes in an all out stop light race a Civic or most any modern vehicle will win, but in everyday traffic their torque let's them keep up just fine without being flogged.

If you want to get 150 hp out of a 100 motor good luck, it can be done, but it will cost you. 20 hp or so is easy, but because the engine doesn't like to rev with the long stroke big gains mean more than a radical cam that can make big power at big revs, but it sounds like you have figured that out.

Lastly, yeah, easier and cheaper to make a 6 cylinder TR go and handle, I did it with my TR250, he'll there is a whole Web page out there just listing cam options, but the cars, while still vintage British, have a whole different vibe than the big Healeys. A 100 with the windshield doen, even a kind of scruffy one, is just pure sex on wheels.
 
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Late to the party, but this might be helpful as I had the same thoughts of building the ultimate 100, until I found someone who beat me too it.
I met the late Mark Baker at the Austin Healey West Coast Meet "Rendezvous" 2003 in Lake Tahoe. This is when he unveiled this spectacle "100R" build. My jaw dropped as did everyone else's, it won best in show. I didn't know Mark well, but spoke to him extensively about the built, the engine work and his passion to stay with a period original appearance. He didn't strike me as one to embellish the engine performance he achieved in this very streetable four-cylinder Healey. He built his owner engines and incorporated a number of modern US performance internal parts to make the HP gains noted. Sports and Specialities may have stay have the build sheet on this car.

https://sportandspecialty.com/portfolio-item/1955-austin-healey-100r/
 
Thank you for the photo of the 100R Dougie. That is one beautiful Healey to gaze upon, I would have loved to get a peek under the bonnet of this particular Healey with a period motor that puts out that kind of horse power.

Come to think of it, I never seen a high preformance BJ8 motor in a 100 Healey yet?
 
Rick, I am always amazed how you come up with these very interesting period photos...The woman driver looks like my aunt! Lol...My uncle used to own a Sprint car race track years ago and I remember the offenhouser powered Sprint cars in many of the family photo albums with my aunt and uncle posing with all the racers. Back then it was very fashionable to be involved with race cars ...My uncle serverd with Bob Hope during WW2 in the U.S.O and went on to become Bob Hopes agent for many years.
 
while stationed at ft sill okla in 1968, i remember lifting the hood on an austin healey ...not sure of the model...and there was a very well done conversion to a very shiny jaguar engine.
 
drambuie said:
Rick, I am always amazed how you come up with these very interesting period photos..
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I've got a huge filing cabinet in my head from almost a half-century of Healeying and then it's just a matter of finding it on the interwebs.

Speaking of which, I remembered that John Chatham got some good horsepower using the block and crank from the diesel Austin FX3 taxi, while Michael Salter adapted the diesel crank to the 100 block. You can see their results here: https://www.acmefluid.com.au/larry/chatham.html and here: https://www.acmefluid.com.au/larry/100r/100rengine.html
 
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Rick--

Salter used the diesel crankshaft to destroke the 100's engine and bring it into the sub-2.5 liter class of the Targa Newfoundland. Though I was listed as "co-driver" Salter did all the driving which was fine with me and I merely navigated. I did drive the car a couple of times and it was quite fast despite the decrease in displacement.
 
dougie said:
Late to the party, but this might be helpful as I had the same thoughts of building the ultimate 100, until I found someone who beat me too it.
I met the late Mark Baker at the Austin Healey West Coast Meet "Rendezvous" 2003 in Lake Tahoe. This is when he unveiled this spectacle "100R" build. My jaw dropped as did everyone else's, it won best in show. I didn't know Mark well, but spoke to him extensively about the built, the engine work and his passion to stay with a period original appearance. He didn't strike me as one to embellish the engine performance he achieved in this very streetable four-cylinder Healey. He built his owner engines and incorporated a number of modern US performance internal parts to make the HP gains noted. Sports and Specialities may have stay have the build sheet on this car.

https://sportandspecialty.com/portfolio-item/1955-austin-healey-100r/
Click to expand...

I had Sport and Specialty do some work on my car a few years ago (wow, this restoration is dragging on as that was several years ago already). I saw this car there shortly before it was sent to auction. It was as nice as everyone says. I did not hear it run or anything like that, just looked it over. Afterwards I did some internet searching to learn more about it. Someone can correct me if I'm wrong but IIRC, this car can not run on pump gas, it requires race gas. I only mention this because the discussion seems to be about making 150+ hp out of the A90 engine and...
 
One of the reasons I posted the video of the 100S was for everyone to take note of the horse power and top speed claim...
132 brake horse power at 4.700 RPM rounding the salt flats at 134 MPH. that was in 1954! Sounds like a false claim or Denis Walsh expensive high preformance parts haven't Improved and developed much compared to what they had in 1954 61 years ago!
 
Over here in the UK the top race 100s are putting out close to 200bhp. Quite an improvement on 132bhp. The car Jeremy Welch built for endurance record breaking at the Millbrook test track in the Uk averaged over 150 mph for 5 miles.
 
Derek

When John Chatham was racing DD300 in the sixties, his car was to works spec and he claimed 200bhp at approaching 6000 rpm. Now some cars are revving to to 7000 and claiming 240-280bhp. Equally some are revving TR4 engines past 8000 and claiming 240.

it will be interesting to see what a carefully built standard BJ8 with a gas flowed head and 10 to 1 compression actually produces. I suspect 115bhp.

I think dynos vary and many claims are exaggerated.
 
Certainly dyno claims can be exaggerated with some firms keen to have their machines read on the high side to increase business. The other thing that confuses the issue is whether we are talking about power at the flywheel or at the rear wheels, a significant difference. I believe the numbers quoted at the time for the Austin Healeys were actually bench test numbers, without connected auxiliary equipment, so not even at the flywheel. All race engines nowadays have all steel engines and rev much higher. 7500 in the case of the 3000s. Cams have been developed to maximise these high revs, coupled with improved head flow design we arrive at the 260-285 bhp numbers we see on the full blown race cars. This is power at the flywheel not the rear wheels. I would think a standard BJ8 with gas flowed head but standard cam would produce about about 130 bhp at the flywheel. My own car has a BJ8 engine with triple Webers and a 300 degree rally cam. It does not have a steel engine I rev generally to 5500, sometimes 6000. It has a ported and polished head, 11:1 compression and balanced crank etc. It was measured on a dyno at 175 bhp at the rear wheels. So about 210 bhp at the flywheel.
 
If I remember correctly, power required increases as the square of the speed. So increasing the speed from 134 to 150 would require an increase in power from 132 to 165.
 
Drag force scales as the square of the speed. Since Power = Force x Speed, the power required actually scales with the cube (or third power) of speed.
 
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