jluna94 Posted March 28, 2018 Report Share Posted March 28, 2018 Hi everyone, I'm going to rebuild my j13 engine and want to supercharge it. Wondering if anyone has has done or taken it to a specialist to do that. I'm located in SoCal. Hope to hear from people's suggestions/options. Greatly appreciated, take care as always. Quote Link to comment
bananahamuck Posted March 28, 2018 Report Share Posted March 28, 2018 Supercharger x 3 main bearings = probably not a well thought out idea 2 Quote Link to comment
Stoffregen Motorsports Posted March 28, 2018 Report Share Posted March 28, 2018 I would start by looking at vintage race cars, like the supercharged MG's of the 30's and 40's. Also, in the 60's there was a bolt on supercharger for MGA and MGB applications. I think it was a Judson. Quote Link to comment
flatcat19 Posted March 28, 2018 Report Share Posted March 28, 2018 This sounds expensive. Quote Link to comment
datzenmike Posted March 28, 2018 Report Share Posted March 28, 2018 Supercharger x 3 main bearings = probably not a well thought out idea This is the first thing I thought. The L series has 5 huge main bearings. 5 pounds boost would be about a 30% increase in power but an SC robs power to run it so 15-20%? Ten would be 66% but with running losses more like 50% increase. A turbo runs on basically free exhaust power. I would beef up the cooling system, add an oil cooler, get a high volume oil pump and shim the relief valve for 65-70 PSI. Next a copper head gasket or O ring the cylinders to prevent any chance of blowing the head gasket out. Quote Link to comment
Stoffregen Motorsports Posted March 29, 2018 Report Share Posted March 29, 2018 Yes, ideally he would be using a different engine, but there is a precedent for supercharging a BMC engine, with which the J series shares it's architecture, If he's got vintage-cool in mind, I see no problem doing this. Here are some links to MG supercharger kits and info - https://www.moss-europe.co.uk/supercharger-kits-mgb.html https://classicmotorsports.com/articles/supercharging-your-mgb/ https://www.barrywalker.com/parts/ Quote Link to comment
DHale_510 Posted March 29, 2018 Report Share Posted March 29, 2018 Back in the day my buddy and I hopped up a few BMC A series motors in a Sprite. We never supercharged one, but did manage to double the power with a little help from Mr DeLong and adding compression and so on. Lifetimes of the motors was dramatically reduced, like about a year of street driving. Others did try the Judson superchargers with almost identical power gains and durability losses. Then we started using bigger engines to the same power with greater durability. My favorite combination was a Datsun R16 roadster motor in a Bugeye Sprite. It was a bolt in after the heater was removed. BMC mounts were interchangeable. Now I would consider a R20 forklift conversion.... I think some guys have replaced their J motors with A13 and A15 motors. Still really old and authentic with less cost, more power, and real durability. The last NOS Judson I saw was asking about $1500 and that was years ago. Maybe a Torquestorm or such could be made to fit but it hardly fits the '50s look. Dennis 2 Quote Link to comment
G-Duax Posted March 29, 2018 Report Share Posted March 29, 2018 Find a good used Aisin AMR500 supercharger. These are being imported out of Japan, and came on the older RA1 Subaru. I used to import & sell both new and used ones, (but no longer), and have figured drive ratios for customers. They have a 17mm input shaft, that is the same as most any alternator, so pulley selection is easy. They have self contained lube, and can take up to 20 psi, and can be turned to 18,000 rpm. Here is an old listing with lots of data: https://www.ebay.com/itm/AMR500-Supercharger-Fiat-500-Geo-Metro-Datsun-VW-Bug-Drag-Bike-Quad-Chopper-/361340629748?nav=SEARCH And: http://vi.vipr.ebaydesc.com/ws/eBayISAPI.dll?ViewItemDescV4&item=361340629748&t=1433686795000&tid=10&category=177783&seller=duax_machine&excSoj=1&excTrk=1&lsite=100&ittenable=false&domain=ebay.com&descgauge=1&cspheader=1&oneClk=1&secureDesc=0 But really, bannahamuck says, 3 main bearings is a real problem. 2 Quote Link to comment
Stoffregen Motorsports Posted March 30, 2018 Report Share Posted March 30, 2018 Back in the day my buddy and I hopped up a few BMC A series motors in a Sprite. We never supercharged one, but did manage to double the power with a little help from Mr DeLong and adding compression and so on. Lifetimes of the motors was dramatically reduced, like about a year of street driving. Others did try the Judson superchargers with almost identical power gains and durability losses. Then we started using bigger engines to the same power with greater durability. My favorite combination was a Datsun R16 roadster motor in a Bugeye Sprite. It was a bolt in after the heater was removed. BMC mounts were interchangeable. Now I would consider a R20 forklift conversion.... I think some guys have replaced their J motors with A13 and A15 motors. Still really old and authentic with less cost, more power, and real durability. The last NOS Judson I saw was asking about $1500 and that was years ago. Maybe a Torquestorm or such could be made to fit but it hardly fits the '50s look. Dennis I don't know if you remember my red '65 Sprite. That had a built 1275 in it and would light the tires up like crazy. Ran well around town too and was very reliable. The key element in that equation is the cam. I chose a cam that made good power, but was easy on valvetrain components. The Datsun A motors are a vast improvement over the antiquated BMC design, while still retaining the vintage vibe. Quote Link to comment
noramost Posted April 4, 2018 Report Share Posted April 4, 2018 I have a brand new still in the box blower for a Mercedes Compress-Air I would sell. I works with a full throttle switch and an AC type clutch to give you a bump on full throttle. You would have to make the manifolds Quote Link to comment
MikeRL411 Posted April 20, 2018 Report Share Posted April 20, 2018 Find a good used Aisin AMR500 supercharger. These are being imported out of Japan, and came on the older RA1 Subaru. I used to import & sell both new and used ones, (but no longer), and have figured drive ratios for customers. They have a 17mm input shaft, that is the same as most any alternator, so pulley selection is easy. They have self contained lube, and can take up to 20 psi, and can be turned to 18,000 rpm. Here is an old listing with lots of data: https://www.ebay.com/itm/AMR500-Supercharger-Fiat-500-Geo-Metro-Datsun-VW-Bug-Drag-Bike-Quad-Chopper-/361340629748?nav=SEARCH And: http://vi.vipr.ebaydesc.com/ws/eBayISAPI.dll?ViewItemDescV4&item=361340629748&t=1433686795000&tid=10&category=177783&seller=duax_machine&excSoj=1&excTrk=1&lsite=100&ittenable=false&domain=ebay.com&descgauge=1&cspheader=1&oneClk=1&secureDesc=0 But really, bannahamuck says, 3 main bearings is a real problem. Then use a late model metric R [1600 cc] engine, they have the 5 main bearing crankshaft configuration . Quote Link to comment
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