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Stubby":2rpwwec4 said:
And good, valid ones!
3/71 on 250xflow
- Thread starter lyonsy
- Start date
And good, valid ones!
Hey drift cortina. The movie Mad Max was right about the allure of the on demand superchargers. They are the bomb that everyone craves after. There is a huge problem, though. An X-flow kit doesn't exist. If it did, it would be better than a turbo, but none exists yet.
Some details based on 16 years of research.
Just be aware. Linc 200 and Gravel Rash, Does 10's and most of the non cross flow turbo 3300 cc Holden guys will beet your a$$ for power per dollar. A supercharger kit is way harder to productionise for low cost because of what I.T. people call 'feature creep' and 'inadequate footprinting'.
Basically, we all suffer from lookin over the fence, and we then start getting messed up over what we see others doing, so we keep adding unrealistic things to our grocery list. That's 'feature creep' Then, we fail to find combinations which work and have the testimony of real people who use them every day. Thats 'inadequate footprinting'. If you suffer from either of these, your project will DIE.
You've gotta find a combo which works, and stick to it like a zealot and not waver from that path. There are no off the shelf blower combos that workA turbo log will always give more power for less dollars than an X-flow, OHC, or DOHC. The intendent costs for the later EFI managed engines is very high, and Linc 200, Does 10's and Gravelrash is the winner of the do more for less process.
The 2/71, 3/71 and 4/71 and 4/53 superchargers can be made to work fine. So can the RO20 and RO34 Wade blowers. They may have clearnace issues, but the pulsing is more of an issue with little superchargers which have a swept capacity of 1.2 ( 61 cubice inches) or 1.4 liters (84 cubic inches). Most GMC blowers have capacities of 142, 208, or 284, or 212 cubes. The Rootes blowers are about 121 or 208 cubes.
I can state catagorically that the only bad combinations are
1) Propane gas carbs which have very sensitive responses to manifold pressure. Century, Impco, OHG, Gas Research have black marks against them when running 9 pounds of boost with two blade Ogura/Toyota SC12 or 14 blowers on 202 to 250 cube Fords and Holdens. At 64 to 84 cubes, they are too small on engines which are likely to make more than 230 hp, and especially so if they are on propane. I'm not knocking any Gas Research LPG or Castelmain Rod shop petrol supercharger conversions, but people who do there own Blown LPG versions based on there adaptors always run into problems when using thse little twin blade items.
2) When you use EFI intakes with a long branchs that creates excessive distances between the gasoline/petrol source and the intake manifold. The legendary Phil Irving had issues with Rolls Royce cabin blowers on 1200 cc Vincent Black Shaddow V-twins. These had to have throttles and blow-out protection in the intake to controll the pulses from thre blower. This is explain in his book Tuning For Speed, a bible for motercylce modifiyers, and still as valid in 2006 as it was in 1976.
The pulses are very much an issue with modern EFI systems, but not draw through or blow through carbs.
I personally believe superchargers will become freeweeling with 5 or 7 rib GM pullies and 6.5 GM Diesel AC clutches.
All testimonals from Aussies who used GMC blowers on the street in the early 90's said that the heat while cruising and the occassinal belt issues are the worst thing about a GMC blower. They need to be clutched like the Castelmain Rod Shops landamark SC14 to GM 3800 coversion. I assure you that this is the only kind of blown engine combination I'd like to sit behind on a day to day basis, as it has the factory economy and V8 power we all want, on deamand. Only issue is you say goodbye to Air cond. There is a 30 % power boost at the flick of the button!So a stock 16 second Holden does low 14's and V8 style burnouts at the flick of a switch, how good is that?
It's only handicap is that the SC 14 blower is too small, has twin blades, and is not as easy to rebuild as the GM blowers. GM blowers are very easy to clearance, look great, and the 3/71's especially are a just the right size to fit on an X-flow or pre-cross flow Ford I6.
The log head engine is easier to fit a blower to, the X-flow requires a lot of lateral thinking. If you check out the Forced Air Technolgies blower used on the AJ-6 EF Falcon prototype and on the AU II, the OHC serpentine belt can be used. These use Sprintex or Whipple Blowers, which are more like the Eaton M90's.
I can't say any more as I've got other projects, but your on the wrong track for budget. Long term, a kit will appear, but you'll never do this unless you have golden pockets and someone who has been there and done it. That's person is not me.
Some details based on 16 years of research.
Just be aware. Linc 200 and Gravel Rash, Does 10's and most of the non cross flow turbo 3300 cc Holden guys will beet your a$$ for power per dollar. A supercharger kit is way harder to productionise for low cost because of what I.T. people call 'feature creep' and 'inadequate footprinting'.
Basically, we all suffer from lookin over the fence, and we then start getting messed up over what we see others doing, so we keep adding unrealistic things to our grocery list. That's 'feature creep' Then, we fail to find combinations which work and have the testimony of real people who use them every day. Thats 'inadequate footprinting'. If you suffer from either of these, your project will DIE.
You've gotta find a combo which works, and stick to it like a zealot and not waver from that path. There are no off the shelf blower combos that workA turbo log will always give more power for less dollars than an X-flow, OHC, or DOHC. The intendent costs for the later EFI managed engines is very high, and Linc 200, Does 10's and Gravelrash is the winner of the do more for less process.
The 2/71, 3/71 and 4/71 and 4/53 superchargers can be made to work fine. So can the RO20 and RO34 Wade blowers. They may have clearnace issues, but the pulsing is more of an issue with little superchargers which have a swept capacity of 1.2 ( 61 cubice inches) or 1.4 liters (84 cubic inches). Most GMC blowers have capacities of 142, 208, or 284, or 212 cubes. The Rootes blowers are about 121 or 208 cubes.
I can state catagorically that the only bad combinations are
1) Propane gas carbs which have very sensitive responses to manifold pressure. Century, Impco, OHG, Gas Research have black marks against them when running 9 pounds of boost with two blade Ogura/Toyota SC12 or 14 blowers on 202 to 250 cube Fords and Holdens. At 64 to 84 cubes, they are too small on engines which are likely to make more than 230 hp, and especially so if they are on propane. I'm not knocking any Gas Research LPG or Castelmain Rod shop petrol supercharger conversions, but people who do there own Blown LPG versions based on there adaptors always run into problems when using thse little twin blade items.
2) When you use EFI intakes with a long branchs that creates excessive distances between the gasoline/petrol source and the intake manifold. The legendary Phil Irving had issues with Rolls Royce cabin blowers on 1200 cc Vincent Black Shaddow V-twins. These had to have throttles and blow-out protection in the intake to controll the pulses from thre blower. This is explain in his book Tuning For Speed, a bible for motercylce modifiyers, and still as valid in 2006 as it was in 1976.
The pulses are very much an issue with modern EFI systems, but not draw through or blow through carbs.
I personally believe superchargers will become freeweeling with 5 or 7 rib GM pullies and 6.5 GM Diesel AC clutches.
All testimonals from Aussies who used GMC blowers on the street in the early 90's said that the heat while cruising and the occassinal belt issues are the worst thing about a GMC blower. They need to be clutched like the Castelmain Rod Shops landamark SC14 to GM 3800 coversion. I assure you that this is the only kind of blown engine combination I'd like to sit behind on a day to day basis, as it has the factory economy and V8 power we all want, on deamand. Only issue is you say goodbye to Air cond. There is a 30 % power boost at the flick of the button!So a stock 16 second Holden does low 14's and V8 style burnouts at the flick of a switch, how good is that?
It's only handicap is that the SC 14 blower is too small, has twin blades, and is not as easy to rebuild as the GM blowers. GM blowers are very easy to clearance, look great, and the 3/71's especially are a just the right size to fit on an X-flow or pre-cross flow Ford I6.
The log head engine is easier to fit a blower to, the X-flow requires a lot of lateral thinking. If you check out the Forced Air Technolgies blower used on the AJ-6 EF Falcon prototype and on the AU II, the OHC serpentine belt can be used. These use Sprintex or Whipple Blowers, which are more like the Eaton M90's.
I can't say any more as I've got other projects, but your on the wrong track for budget. Long term, a kit will appear, but you'll never do this unless you have golden pockets and someone who has been there and done it. That's person is not me.
hey
yeah everyone says go turbo but the turbo cars ive driven stock and worked just dont do it for me.
i hate having to wait for the power to come on like all the turbo car's ive driven.
so i was going to build a tough n/a engine as i thought about the little sc14 blower but i whould need to to do anything so not good.
then this 3/71 come up thats in pretty good shape pretty cheap.
and yeah having a blower on off switch whould be seriously good but dont know if it whould work as a mate done a twin sc14 blower setup on 253 holden and has had major problems with sliping on the serptine belt.
if you could get it not to slip then then all you whould need is adapt up a aircon elec clutch.
drift
yeah everyone says go turbo but the turbo cars ive driven stock and worked just dont do it for me.
i hate having to wait for the power to come on like all the turbo car's ive driven.
so i was going to build a tough n/a engine as i thought about the little sc14 blower but i whould need to to do anything so not good.
then this 3/71 come up thats in pretty good shape pretty cheap.
and yeah having a blower on off switch whould be seriously good but dont know if it whould work as a mate done a twin sc14 blower setup on 253 holden and has had major problems with sliping on the serptine belt.
if you could get it not to slip then then all you whould need is adapt up a aircon elec clutch.
drift