Regular members will recall my Panther trike with 3 speed vW auto Type 3 Box. The 1916cc VW engine was sold off after many issues. I purchased a used EA81 from a subaru mechanic that had renewed rings and bearings 80,000 kms ago (now 110,000). I ran a weber (that Brumby kid ended up aquiring) and electronic dizzy rebuilt.
I wasnt fully happy with the result. The EA81 would rev much better than the twin carbed (webers) VW engine and had a little better acceleration. Economy was good at around 8l/100kms to 11l/100kms. But hook it up to my mini caravan and the slightest hill would see me dropping it down to second gear. It just didnt have the power and torque output required. This is despite the trike weight of 550kgms and a van weight of 520kgms total 1070 kgms and a little extra parachute effect from the trike roof. The auto box, as seen on the dyno, sapped 14hp from the engine. Outputs were NA 59hp, SC12 82hp ATW.
Many said I should have gone EJ20 or similar and have some regret I didnt. However as I've now settled with the EA81 and spent lots on the exhaust etc I want to stick with this very simple engine.
I bought a Toyota SC12 and being mechanically inexperienced still managed to install it suck through with a 40DCOE Dellorto. This was eventually dynoed for jetting and dizzy reset for boost. Custom twin exhaust had connecting pipe etc. So I've done all the right things. The extra power throughout the rev range is impressive and totally satisfies me at 5psi boost and I could raise that to 7-8psi without risking reliability. What I wasnt prepared for was the poor economy.
I want to fix the poor economy. I want to be legal eg engineers report easily obtained. I want the whole mechanical driveline to be oil leak free, painted and even parts chromed. This is near a show trike so why not get it looking like one? So an extra auto box and transaxle might be sort also and the whole lot fully assembled prior to install. As the trike is operational I dont care how long this project takes and expect this thread to have its quiet times as I save for the next development.
My plan briefly is this:
Buy a EA81 for rebuild keeping in mind it will be built for boost.
SC set up will be blow through. Buy a sealed carbie preferrably downdraft this time, a single throat will do maybe a Holley or ready sealed units like Mighty Demon. http://www.wpsracing.com/ca750cfmmide.html
Upgrade the Sc to either SC14 or if funds are ok to a sprintex twin screw SC. SC's like the Sprintex are much more efficient and run cooler, essentially they sap less power to turn but I dont think they have a on/off switch pulley set up.
The other alternative is to go EJ20. I'll be frank and say I dont want to do this. I'd be discarding my $1600 exhaust system or chopping it, and the eCU/EMU etc etc scares the crap out of me even though I know my mate Bennie would help me join those wires up. The other reason is that the eA81 like the vW engine hangs off the transaxle and on a monocoque chassis from Panther there is no way you can have engine mounts. This might give an engineer a headache and me many regrets. And remember- I'm happy with the EA81 SC12 output.
There is no alternative with the auto box. The trike was built around it and therefore fits like a glove. The auto Subaru boxes are at least 140mm longer requiring the rear wheels to be moves aft that much (Up front the tank is in the way and not able to modify). The swing arms are hand made alloy box section and would need to be longer. It just isnt worth it and could spoil it.
So, a similar refined set up like I have now with much better economy is the goal. As 90% of the time power needs are low like cruising without towing a switch for instant boost is I think the way to go.
Your thoughts?
Tony
, that's if your interested?
