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rebuild motor
- Thread starter rjc157
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Keoke
Great Pumpkin
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I agree with Keoke.
Healey Nut
Luke Skywalker
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Yep...... if you want power its gonna cost ya ......HP=$$$$
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I'd wait for the guys that regularly do this, like Dougie and Richard Mayor, before giving up hope. My best guess is you'll be looking at triple 2" SUs, raised compression, some head work and exhaust headers. It would be best to find someone who has done the modifications you're considering and using it in the way you plan on using it. 200 hp in a motor used just on track will be fairly "mild", but the same motor used on the street might suffer from cooling problems on a warm day in traffic. One of the difficulties with "hot rodding" a Healey motor is it's not just a matter of bolting on parts, like an American V8. There are lots of bolt on cylinder heads, intakes and headers, along with cam choices for someone to make a good estimate of the power a V8 will put out. With a Healey, there aren't a lot of choices for modified cylinder heads that will bolt on and finding an engine shop that can modify your existing head is going to be kind of difficult. If you're working on a budget and planning on a rebuild anyway, it might be easiest to approach this from the standpoint of "which modifications can I do that will give me the most power, ensure street driveability, and cost no more than a certain amount of money" and then determine if that will satisfy you.
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Keoke,
My BJ7 was turned into an SCCA racer in 1965 and my first rebuild turned it back to its status at that time with triple HD8s, modified head and an Isky T3 cam. I'm guessing about 160 bhp at that time, but it just wasn't enough for me and led to the V8 conversion. My point is merely that once one starts deviating from stock, they need to have a good idea of their goal and how to reach it. Modifying a Healey six is not cheap, but within certain parameters is still cheaper than swapping in a V8. It all depends on the builder's vision. For some, they want to keep it close to original Healey and hopping up the Healey motor is the way to go. But I'll guarantee you that if I turn my keys over to a stock Healey owner, they'll get out with a smile on their face. Nevertheless, we all have to decide on the Healey we want. Some of us want stock, others modified, and others nasty. Make your decision and proceed accordingly.
My BJ7 was turned into an SCCA racer in 1965 and my first rebuild turned it back to its status at that time with triple HD8s, modified head and an Isky T3 cam. I'm guessing about 160 bhp at that time, but it just wasn't enough for me and led to the V8 conversion. My point is merely that once one starts deviating from stock, they need to have a good idea of their goal and how to reach it. Modifying a Healey six is not cheap, but within certain parameters is still cheaper than swapping in a V8. It all depends on the builder's vision. For some, they want to keep it close to original Healey and hopping up the Healey motor is the way to go. But I'll guarantee you that if I turn my keys over to a stock Healey owner, they'll get out with a smile on their face. Nevertheless, we all have to decide on the Healey we want. Some of us want stock, others modified, and others nasty. Make your decision and proceed accordingly.
Or another marque's 6 cylinder motor, 5 speed with 240-300 hp, allowing install without any cutting. You can then always go back to stock.
https://www.rebelloracing.com/enginebuild.htm
https://www.rebelloracing.com/enginebuild.htm
The Dennis Welch BJ8+cam, gas flowing and larger valves, balancing and a lighter flywheel plus triple Webers gives around 130bhp on an accurate rolling road. Tickover is a tad lumpy, but it clears instantly on pick up.
The old Morris Isis engine is wonderfully smooth and torquey and it lasts for ever, but only fierce cams give it more power and then you ruin it for the road.
I'm a few miles from Spamspeed and John Chatham, so have reliable information.
The old Morris Isis engine is wonderfully smooth and torquey and it lasts for ever, but only fierce cams give it more power and then you ruin it for the road.
I'm a few miles from Spamspeed and John Chatham, so have reliable information.
Bob_Spidell
Yoda
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It's expensive.
$1,800 for a manifold? And what's worse, there isn't even a dyno test telling you what kind of horsepower gains it makes. It's a shame that there are no books or magazine articles for the six cylinder on how to get more horsepower out of the six cylinder. Most of the six cylinder stuff is aimed at racing, not "fast road" info. Compare this to the Sprite where there are exccellent tuning books like David Vizard's or Daniel Stapleton's that give hands on advice for owners that want just a little more performance or an all-out racer.Chris_Masucci
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Why would anyone pay that from Moss when you can get the same from AH Spares for much much less?
https://www.ahspares.co.uk/austin-healey/performance-parts/Fuel/FAST-FLOW-INLET-MANIFOLD-2.aspx
I bought one when I had to order some stuff from them, figuring while I was already paying for overseas shipping I may as well make it worth it. I haven't installed it yet, but it sure is pretty. Super nice casting too.
https://www.ahspares.co.uk/austin-healey/performance-parts/Fuel/FAST-FLOW-INLET-MANIFOLD-2.aspx
I bought one when I had to order some stuff from them, figuring while I was already paying for overseas shipping I may as well make it worth it. I haven't installed it yet, but it sure is pretty. Super nice casting too.
Bob_Spidell
Yoda
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Assume this is from DMD/Aus. Their original design required side-draft--not semi-side draft--HD carbs, and probably some mods to the shroud. Does this one?
I suspect that manifold will produce more torque and it may help with tick over if you're using a hotter camshaft. This is because the inlet tracts are longer to reduce the chances of one cylinder pinching another's fuel. Modern engines do the same.
Tuning up Healey engines is much the same as for the A Series, or any engine really. Gas flowing and Carburettor changes make very small differences because the manufacturers got it right when they designed the car. This leaves camshafts and they can make a huge difference, but by shifting power up the rev range and increasingly sacrificing torque until you have an engine like Marc Campfield's that revs to 7000 and won't run below about 5000!
Revs are what produce power, so for more you have to fit a fiercer camshaft. IMO a standard car with a higher axle ratio for more relaxed touring is best unless you're a racer.
They do make a good noise though. We bought our first Healey from John Chatham in the sixties and we used to watch him race then.
Tuning up Healey engines is much the same as for the A Series, or any engine really. Gas flowing and Carburettor changes make very small differences because the manufacturers got it right when they designed the car. This leaves camshafts and they can make a huge difference, but by shifting power up the rev range and increasingly sacrificing torque until you have an engine like Marc Campfield's that revs to 7000 and won't run below about 5000!
Revs are what produce power, so for more you have to fit a fiercer camshaft. IMO a standard car with a higher axle ratio for more relaxed touring is best unless you're a racer.
They do make a good noise though. We bought our first Healey from John Chatham in the sixties and we used to watch him race then.
I agree w/HealeyRick, $1800 for a Moss manifold is crazy, having worked in a turbo shop & having run many engines/cars on a Dyno, I have to disagree with the statement "Revs are what produce power", torque is what moves cars. You can rev an engine way past it's peak torque & or hp and achieve little gain besides stressing your engine, most engines reach there peak long before redline or rev limit is achieved. Honda guys used to be great at bragging it revs to 8500 rpm, Why? I would ask, power fell off 1500 rpm ago. cheers
DerekJ
Luke Skywalker
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Genos,
Revs do produce power because power is Torque (ft/lb) * Revs per minute / 5252. However you are right to say that at a certain level of revs the car's maximum power will be achieved and any further revs result in reduced power. The power curve for my car peaks at 5500 and falls off after that.
Revs do produce power because power is Torque (ft/lb) * Revs per minute / 5252. However you are right to say that at a certain level of revs the car's maximum power will be achieved and any further revs result in reduced power. The power curve for my car peaks at 5500 and falls off after that.
DerekJ
Luke Skywalker
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I love watching that video. Nigel Greensall is a great driver, so smooth and calm. Costs a fortune to get the car to that level. Even getting to 200 bhp costs a lot. You have to remember that the original bhp numbers that BMC published were set on a bench with no ancillaries. This means that a standard 3000 only has about 105 bhp and a BJ8 about 130bhp at the flywheel. DD300 puts out about 270bhp. That's a huge increase. It revs to 7500.
A DWR fast road cam with twin 2 inch SUs, polished and ported head etc will get you around 160 bhp. Put in the DWR rally cam and you should be around 185 bhp. Mine has the rally cam, triple Webers and 11:1 compression and gets about 210 bhp.
A DWR fast road cam with twin 2 inch SUs, polished and ported head etc will get you around 160 bhp. Put in the DWR rally cam and you should be around 185 bhp. Mine has the rally cam, triple Webers and 11:1 compression and gets about 210 bhp.