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To Supercharge or not
- Thread starter Jayrz
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mccalebr
Jedi Knight
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I couldn't tell you. What I do know is what Hap has to say about it; in the following post he writes:
https://www.britishcarforum.com/bcforum/ubbthreads.php/ubb/showflat/Number/309691/fpart/2
"Well I never dynoed one, because people building these engines don't want to pay $600-700 for dynoing, but based on other engines I built, you should be looking at aprox. 80 horsepower at the flywheel. Cam and compression are two things engines respond to the most, so even with my basic engine, they get a cam upgrade and a compression boost, after that it is a bunch of money for smaller gains. Porting a head would be the next thing in line, but that raise the budget over a stock reman head a good $700-900 extra."
That's in response to a description of an engine being built by another builder along the lines of what Hap puts into his standard street engine.
I've encouraged Hap to go a bit beyond this, porting the head for example, on my engine so I'm expecting good performance.
I have a Midget that I show with an engine built by Dave Taber...one of his last. Although the car is a '73 the engine was built to '67 specs. I'd guess 80 hp...which in that little car, with a Rivergate 5 speed, is plenty for me.
Ray
https://www.britishcarforum.com/bcforum/ubbthreads.php/ubb/showflat/Number/309691/fpart/2
"Well I never dynoed one, because people building these engines don't want to pay $600-700 for dynoing, but based on other engines I built, you should be looking at aprox. 80 horsepower at the flywheel. Cam and compression are two things engines respond to the most, so even with my basic engine, they get a cam upgrade and a compression boost, after that it is a bunch of money for smaller gains. Porting a head would be the next thing in line, but that raise the budget over a stock reman head a good $700-900 extra."
That's in response to a description of an engine being built by another builder along the lines of what Hap puts into his standard street engine.
I've encouraged Hap to go a bit beyond this, porting the head for example, on my engine so I'm expecting good performance.
I have a Midget that I show with an engine built by Dave Taber...one of his last. Although the car is a '73 the engine was built to '67 specs. I'd guess 80 hp...which in that little car, with a Rivergate 5 speed, is plenty for me.
Ray
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I just acquired some Road & Tracks from the 60s, every issue has an ad somewhere for the Judson superchargers for less than $200 (for Sprites). There had to have been a number of them sold, but they seem to be a pretty rare commodity these days, did those things have a limited working life? Did the cars they got put in get rode hard, put up wet and scrapped? Just curious.
As far as Supercharger v. NA with mods, the A series is a great engine to hot rod, as mentioned depends on how you want to drive and how much you want to spend, as I get older I am less inclined to wind out my motor to the redline all the time (guess I am more aware that parts do wear out) so I would probably enjoy the more relaxed improvements of the supercharger more. However I also know of and have driven Sprites with mods that do to produce 100hp, but maybe are up to 75-85HP or so with a modest cam, compression and breathing improvements and have good torque low down and are very nice civil cars to drive with noticeable extra oomph. Just depends on how far you want to go.
As far as an engine swap, in addition to just getting the motor and tranny in and running you will probably want to have guages (tach, speedo, oil presure, temp.) that work with the new motor--this will either mean aftermarket guages or the old guages with a lot of modification and engineering to make them work right--in my car (big healey, not sprite, but same principles apply) this latter put me off on an engine swap more than the actual fitting of a different motor. As in, after all the work of putting in the motor, you will then have to either butcher up the dash with non stock guages, or spend a lot of time and money making the stock ones work with the new motor. I know some don't care as much about this issue, but it is a consideration.
As far as Supercharger v. NA with mods, the A series is a great engine to hot rod, as mentioned depends on how you want to drive and how much you want to spend, as I get older I am less inclined to wind out my motor to the redline all the time (guess I am more aware that parts do wear out) so I would probably enjoy the more relaxed improvements of the supercharger more. However I also know of and have driven Sprites with mods that do to produce 100hp, but maybe are up to 75-85HP or so with a modest cam, compression and breathing improvements and have good torque low down and are very nice civil cars to drive with noticeable extra oomph. Just depends on how far you want to go.
As far as an engine swap, in addition to just getting the motor and tranny in and running you will probably want to have guages (tach, speedo, oil presure, temp.) that work with the new motor--this will either mean aftermarket guages or the old guages with a lot of modification and engineering to make them work right--in my car (big healey, not sprite, but same principles apply) this latter put me off on an engine swap more than the actual fitting of a different motor. As in, after all the work of putting in the motor, you will then have to either butcher up the dash with non stock guages, or spend a lot of time and money making the stock ones work with the new motor. I know some don't care as much about this issue, but it is a consideration.
aeronca65t
Great Pumpkin
Offline
Reminder:
No matter which route you take (naturally aspirated, turbo or supercharge), remember that you have to buy gas for this thing afterwards.
My 1500 with roughly 10.25:1 comp requires 100 octane. I buy the Sunoco unleaded race gas (about $7 USD per gallon). This is not a big problem for me since I rarely use more that 20 gallons in a weekend. But in a street car, this could get to be tough.
The "octane boost" additives are almost useless.
You *could* back off your igniton timing, but then, what's the point of doing all this hot rod work in the first place?
You can get a 1275 that puts out about 80 HP to run on 93 octane, but probably just barely.
80 HP is great in a street Spridget, so that's a good number to shoot for. I doubt my race car has much more than that.
I don't think there's any way to run a 100 HP 1275 on street gas if it's really tuned for 100 HP. (I'm talking about the best 93 octane RON unleaded gas available in the USA)
No matter which route you take (naturally aspirated, turbo or supercharge), remember that you have to buy gas for this thing afterwards.
My 1500 with roughly 10.25:1 comp requires 100 octane. I buy the Sunoco unleaded race gas (about $7 USD per gallon). This is not a big problem for me since I rarely use more that 20 gallons in a weekend. But in a street car, this could get to be tough.
The "octane boost" additives are almost useless.
You *could* back off your igniton timing, but then, what's the point of doing all this hot rod work in the first place?
You can get a 1275 that puts out about 80 HP to run on 93 octane, but probably just barely.
80 HP is great in a street Spridget, so that's a good number to shoot for. I doubt my race car has much more than that.
I don't think there's any way to run a 100 HP 1275 on street gas if it's really tuned for 100 HP. (I'm talking about the best 93 octane RON unleaded gas available in the USA)
racingenglishcars
Darth Vader
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I used to have two Judson superchargers. One installed in my own BE, the other I gave to a friend with a 67. I got them used, though not much used, but imho, the build quality and design were s---. They are a vane type (known from air drills and the blades wear out and break very quickly.
The FIA approved a Shorrock supercharger ( HERE's a direct link to the applicable page of the certification).
I've only seen one at the races here, so I don't think it's quality is any better than the Judson.
I would still go with the Hi-Flow unit.
The FIA approved a Shorrock supercharger ( HERE's a direct link to the applicable page of the certification).
I've only seen one at the races here, so I don't think it's quality is any better than the Judson.
I would still go with the Hi-Flow unit.
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Interesting point about gas, Nial. Here in Utah the best pump gas is 91 octane. I think it has something to do with the elevation here (4500' at the SLC valley floor, I'm at 5550'). I know I'm not going to make the full power possible here due to elevation issues, but it's a good reminder for me to remember the gas issues here as well.
racingenglishcars
Darth Vader
Offline
We can still get 98
kcbugeye1275
Jedi Knight
Offline
I drove a stock cammed 1275 with a little head work, headers and a couple other small improvements(I'm guessing maybe 70 hp) for several yrs with a 5 speed tranny. It was a lot of fun, but my opportunity came to build a motor for the SC, it was just the right place in my life to do it. With the new motor came a repainting of the car, completely redoing the bonnet, new wiring harness, and reworking the hyd. to the modern master cyls. These are all decision one makes along the way and now my BE is a great driver that will accelerate with a modern car. Of course, the BE will not compete with a modern high performance car. Everybody is correct in that you can spend quite a bit of money, and for simple fun, the 70 hp motor was probably more fun for the dollar. However, I now have that rare non oil leaking lbc that I plan on keeping and one day giving to my youngest son. It has been my experience that what seems to be a lot of money today isn't that much several yrs later. The one thing I would be concerned about with a higher comp motor is the octane issue, make sure the motor you build will run on 91.
Westfield_XI
Jedi Warrior
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100hp out of a normally aspirated 1380 will not be cheap, not only for the parts, but also for all the handwork on the rods, crank, head and carbs. IMHO it takes years of experience to learn all the tricks of engine building. Not just how to port and polish and select the correct power parts, but how to do the myriad of small tasks that allow an engine to develop almost twice the design hp and still live for an acceptable period of time. I do not have the skills to do this and no amount of studying Vizard's book will give it to me, so I would have to regress to learning on my own engine and replacing the ruined parts as I go. In the long run it's a lot simpler to pay a pro who will stand behind his work, in my case APT, unfortunately it is enormously expensive. And very slow, my delivery date has "slipped" 10 months!!! Luckily my entire project was delayed for other reasons and I am not held up by the engine.
Things might be cheaper and faster in other areas, but in SoCal thats the way it is.....
Things might be cheaper and faster in other areas, but in SoCal thats the way it is.....
Jim_Gruber
Yoda
Offline
I got this note back from Hans Pedersen re. pricing for the Hi-Flow Supercharger Product. A tad bit pricier than the MOSS Product. So much for the US Dollar buying power overseas these days.
Hi Jim. Thank you for your enquiry.
Our supercharger kit is designed to be fitted to a basically stock engine.
Provided the engine is in good condition, and within manufacturers tolerances there is generally no extraordinary mods. required in the milder stages of tune.
Bearing in mind that some of these vehicles are now nearly 40 years old, and more than likely, have been rebuilt or modified from the standard specification, this must be taken into account when designing a successful supercharger system. Many rebuilt engines have a higher than original comp. ratio, and camshaft changes are often made at the time of rebuild.
However, many mod's which work with conventional tuning can also be successfully employed on supercharged applications.
Generally we find that the 96 octane (roughly similar to 91 US) fuel available here is the limiting factor in safe power production.
Therefore we need to ascertain the actual ratio of each individual vehicle to establish just how much boost could safely be used. We tailor each kit to suit chosen engine spec. and available fuel octane.
Excellent results have been possible with 8.0 and 8.5: 1 comp. ratios.
Prior to delivery we will require the following engine details:
Bore size (if altered from stock)
Stroke (if altered from stock)
Compression ratio, (or preferably cc of comb. chamber, cc of piston bowl, deck height)
Fuel (octane rating) available
Desired boost (or power) be realistic now !!!!!
Camshaft timing profile,
Fuel (octane rating) available
Power would start around 30% improvement over standard and could reach 100% given the correct set-up.
In our kit fuel requirements are taken of by the SU HIF 6 carby supplied (the metering needle fitted may require slight changes to suit each individual installation). The distributor advance curve should, ideally, be modified to suit the engine's new requirement, or we can supply a brand new Bosch distributor with a suitable curve.
Our comprehensive kit includes all components (incl. new SU carby and K&N filter) to convert a standard Spridget to a supercharged Spridget, including detailed fitting notes.
The export price of our Spridget kit is $6056.00 AUD,
and air freight would be around $270.00 AUD (Europe&Nth.America).
Insurance (if desired) an additional $100.00 AUD.
Regards,
Hans J. Pedersen
HP High Performance Products
Victoria. Australia
Ph. +61 3 9874 1800
https://www.hi-flow.com
hans@hi-flow.com
Hi Jim. Thank you for your enquiry.
Our supercharger kit is designed to be fitted to a basically stock engine.
Provided the engine is in good condition, and within manufacturers tolerances there is generally no extraordinary mods. required in the milder stages of tune.
Bearing in mind that some of these vehicles are now nearly 40 years old, and more than likely, have been rebuilt or modified from the standard specification, this must be taken into account when designing a successful supercharger system. Many rebuilt engines have a higher than original comp. ratio, and camshaft changes are often made at the time of rebuild.
However, many mod's which work with conventional tuning can also be successfully employed on supercharged applications.
Generally we find that the 96 octane (roughly similar to 91 US) fuel available here is the limiting factor in safe power production.
Therefore we need to ascertain the actual ratio of each individual vehicle to establish just how much boost could safely be used. We tailor each kit to suit chosen engine spec. and available fuel octane.
Excellent results have been possible with 8.0 and 8.5: 1 comp. ratios.
Prior to delivery we will require the following engine details:
Bore size (if altered from stock)
Stroke (if altered from stock)
Compression ratio, (or preferably cc of comb. chamber, cc of piston bowl, deck height)
Fuel (octane rating) available
Desired boost (or power) be realistic now !!!!!
Camshaft timing profile,
Fuel (octane rating) available
Power would start around 30% improvement over standard and could reach 100% given the correct set-up.
In our kit fuel requirements are taken of by the SU HIF 6 carby supplied (the metering needle fitted may require slight changes to suit each individual installation). The distributor advance curve should, ideally, be modified to suit the engine's new requirement, or we can supply a brand new Bosch distributor with a suitable curve.
Our comprehensive kit includes all components (incl. new SU carby and K&N filter) to convert a standard Spridget to a supercharged Spridget, including detailed fitting notes.
The export price of our Spridget kit is $6056.00 AUD,
and air freight would be around $270.00 AUD (Europe&Nth.America).
Insurance (if desired) an additional $100.00 AUD.
Regards,
Hans J. Pedersen
HP High Performance Products
Victoria. Australia
Ph. +61 3 9874 1800
https://www.hi-flow.com
hans@hi-flow.com
Trevor Jessie
Yoda
Offline
Yup, his kit used to be more affordable (two years ago), but the weak dollar kills the deal.
kcbugeye1275
Jedi Knight
Offline
Boy, I could get into some political bashing about the value of the US dollar, but... You have seen me express my feelings about the cost today on spending money for the BE verses that money you may or may not have tomorrow. All I can tell you that with a properly built SC motor, it will pull from 1500 rpm up and it is alot of fun. Now, I do have an issue with heat, mine isn't where I can't run in the heat of the summer, but it does run warmer than I would like, and I want to make the car where I simply don't have to worry this issue. Hope it'll be bullet proof by next summer.
Smilin' Ric
Freshman Member
Offline
Hello,
I am in the middle of building a 1275 with a Judson for my '60 Bugeye. I'm getting a lot of conflicting information on the specs. Hoping you can help with some real world practical experience. What compression ratio are you running? And cam? The machinist looking at my block said it will clean up fine with a .020" bore. Did you have to bore your block?
At what RPM range do you feel the boost? Again, getting conflicting info, but around 1,600 to 1,750 has been mentioned a few times. And that it is best to generally limit the upper end to about 6,000. Your thoughts?
I appreciate any help you can offer.
Cheers,
Ric
I am in the middle of building a 1275 with a Judson for my '60 Bugeye. I'm getting a lot of conflicting information on the specs. Hoping you can help with some real world practical experience. What compression ratio are you running? And cam? The machinist looking at my block said it will clean up fine with a .020" bore. Did you have to bore your block?
At what RPM range do you feel the boost? Again, getting conflicting info, but around 1,600 to 1,750 has been mentioned a few times. And that it is best to generally limit the upper end to about 6,000. Your thoughts?
I appreciate any help you can offer.
Cheers,
Ric
Offline
Ric, can't help with your questions but it is worth noticing that the thread is 13 years old so you might not get a quick answer or an answer at all - sorry.
OTOH it might be worth contacting Hap Waldrop - http://www.acmespeedshop.com/ he knows everything!
Smilin' Ric
Freshman Member
Offline
John-Peter,
Thanks for the suggestion, and coincidentally enough, he has reached out to me and we spoke this afternoon about the project. Seems a great guy.
Cheers,
Ric
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