Supercharged 12V/Stratos copy/engine tech type stuff
Posted: Thu Jan 07, 2010 5:59 am
Given a couple of you chaps have asked, I'll start this topic on my current project.
To save sending you off to the other threads, a quick intro to it.
Lancia Stratos copy. It's a UK kit car, originally a Litton, then CAE, now Napiersport Corse. It has strut rear suspension, wishbone front. Chassis is custom, some suspension parts are Lancia, some are Fiat, most are custom. Original engine when I built it was a stock 2l Lancia twin cam from a Monte Carlo, with a Beta gearbox.
Always intended it to be Alfa V6 power, so not long after getting it road legal, I put in a stock 12V 164 motor and gearbox. Sadly, this soon developed a tick on load and soon after a very bad case of smoking. I'd done nothing to the engine other than take it out of the dead 164 it came in and give it a clean/coat of paint, so I can't be blamed for that one!
Next step was to rebuild the engine I'd originally wanted to put in it. I wanted to do a basic stock rebuild, as I always had in mind to try a wee bit of boost on it. Sadly, at the time I was doing the build, I could only get S pistons, and the cams were FUBAR so I ended up with a pair of C&B 'mild' Cams. I ran it in using stock Motronic then installed an aftermarket management system (Emerald M3D). At the first mapping session, it made 198bhp/208ftlb at the flywheel. MUCH later on, I found out the rear cam was 1 tooth out so realistically, I'd expect it to do a little better than this now. It turned out the marks on the cam caps were wrong. The camwheel marks were OK though...but I trusted the cam caps. Idiot! Now I don't trust anything - I dial them in.
Ran the car in this form for a while but started work on a supercharger installation. Unfortunately, I'd already gone a very long way down a particular path before I 'discovered' Greg, so he's been doing a bit of a rearguard action trying to stop me making too many more mistakes.
First effort at supercharging wasn't great. 10:1 CR, cams with too much overlap and a timing error, pretty much totally knackered M90 blower. It made 5psi, 1bhp less than aspirated (but more torque). Next step was to spin the blower faster which helped - it made 8psi and felt stronger as you'd expect, but then it popped a head gasket. Pretty sure this was nothing more sinister than a cheap crappy gasket but I decided at this point to give up on supercharging this engine so fixed the gasket and returned it to aspirated.
Second effort is almost ready to prove it's worth. This is much more to Greg's formula. A set of his 8.8:1 Venolia pistons, a pair of cams from Richard J, his design, based on spec and my intended use for the car, another M90 blower, this time rebuilt and ported to supposedly make more boost/flow better/be more efficient. (I say supposedly, as I had a very bad experience with the company getting the thing sent to me in the first place, and then finding that it leaked oil when it arrived due to sloppy assembly/preparation. If it turns out it works well, then fair enough, I'll live with the agro). I've also done some valve/seat work based on advice from Richard J. Crank is stock, although I used main bearing shells from the NORD engine as they are slightly tighter and 3mm wider than the V6 ones (and cheaper). I had the engine balanced by Vibration Free here in the UK. They do it as an assembly of the rotating/reciprocating parts, having matched pistons and rods. While I was there, I had them balance it with both the stock 3l flywheel and one from a 155 V6, which is a lot lighter. Rods are stock too, as I don't intend revving it that hard, but realistically, I suspect it'll run out of puff before revs become limiting anyway. I know stock rods are good for more torque than mine will make - a mate had a twin turbo 12V that made over 400lbft on stock rods.
Induction setup is stock 164 TB grafted to the M90, a 40mm bike TB as a blower bypass, actuated by a vacuum capsule, the cooler core from a Jaguar XKR grafted into a 164 plenum, then stock runners into the heads with WI nozzles in each runner. The exhaust was stock cast manifolds into a somewhat small and very noisy 'silencer'. Latest effort is a pair of 24V 164 manifolds with 12V flanges fitted, into 2" secondaries and a pair of 2 1/2" bore cans, 6" diameter and 24" long - roughly 85% more volume than the old system. Depending on which figures you use, this shouldn't be restrictive up until about 400bhp or so, but time will tell. It's got to be better than the old system though.
OK, enough waffle, some random photos for now. Questions and ideas always welcome.
To save sending you off to the other threads, a quick intro to it.
Lancia Stratos copy. It's a UK kit car, originally a Litton, then CAE, now Napiersport Corse. It has strut rear suspension, wishbone front. Chassis is custom, some suspension parts are Lancia, some are Fiat, most are custom. Original engine when I built it was a stock 2l Lancia twin cam from a Monte Carlo, with a Beta gearbox.
Always intended it to be Alfa V6 power, so not long after getting it road legal, I put in a stock 12V 164 motor and gearbox. Sadly, this soon developed a tick on load and soon after a very bad case of smoking. I'd done nothing to the engine other than take it out of the dead 164 it came in and give it a clean/coat of paint, so I can't be blamed for that one!
Next step was to rebuild the engine I'd originally wanted to put in it. I wanted to do a basic stock rebuild, as I always had in mind to try a wee bit of boost on it. Sadly, at the time I was doing the build, I could only get S pistons, and the cams were FUBAR so I ended up with a pair of C&B 'mild' Cams. I ran it in using stock Motronic then installed an aftermarket management system (Emerald M3D). At the first mapping session, it made 198bhp/208ftlb at the flywheel. MUCH later on, I found out the rear cam was 1 tooth out so realistically, I'd expect it to do a little better than this now. It turned out the marks on the cam caps were wrong. The camwheel marks were OK though...but I trusted the cam caps. Idiot! Now I don't trust anything - I dial them in.
Ran the car in this form for a while but started work on a supercharger installation. Unfortunately, I'd already gone a very long way down a particular path before I 'discovered' Greg, so he's been doing a bit of a rearguard action trying to stop me making too many more mistakes.
First effort at supercharging wasn't great. 10:1 CR, cams with too much overlap and a timing error, pretty much totally knackered M90 blower. It made 5psi, 1bhp less than aspirated (but more torque). Next step was to spin the blower faster which helped - it made 8psi and felt stronger as you'd expect, but then it popped a head gasket. Pretty sure this was nothing more sinister than a cheap crappy gasket but I decided at this point to give up on supercharging this engine so fixed the gasket and returned it to aspirated.
Second effort is almost ready to prove it's worth. This is much more to Greg's formula. A set of his 8.8:1 Venolia pistons, a pair of cams from Richard J, his design, based on spec and my intended use for the car, another M90 blower, this time rebuilt and ported to supposedly make more boost/flow better/be more efficient. (I say supposedly, as I had a very bad experience with the company getting the thing sent to me in the first place, and then finding that it leaked oil when it arrived due to sloppy assembly/preparation. If it turns out it works well, then fair enough, I'll live with the agro). I've also done some valve/seat work based on advice from Richard J. Crank is stock, although I used main bearing shells from the NORD engine as they are slightly tighter and 3mm wider than the V6 ones (and cheaper). I had the engine balanced by Vibration Free here in the UK. They do it as an assembly of the rotating/reciprocating parts, having matched pistons and rods. While I was there, I had them balance it with both the stock 3l flywheel and one from a 155 V6, which is a lot lighter. Rods are stock too, as I don't intend revving it that hard, but realistically, I suspect it'll run out of puff before revs become limiting anyway. I know stock rods are good for more torque than mine will make - a mate had a twin turbo 12V that made over 400lbft on stock rods.
Induction setup is stock 164 TB grafted to the M90, a 40mm bike TB as a blower bypass, actuated by a vacuum capsule, the cooler core from a Jaguar XKR grafted into a 164 plenum, then stock runners into the heads with WI nozzles in each runner. The exhaust was stock cast manifolds into a somewhat small and very noisy 'silencer'. Latest effort is a pair of 24V 164 manifolds with 12V flanges fitted, into 2" secondaries and a pair of 2 1/2" bore cans, 6" diameter and 24" long - roughly 85% more volume than the old system. Depending on which figures you use, this shouldn't be restrictive up until about 400bhp or so, but time will tell. It's got to be better than the old system though.
OK, enough waffle, some random photos for now. Questions and ideas always welcome.