SR20xxx Midget Motor-> Any known decent research or development out there?
G'Day
I'm developing my own engine to go into a speedway F2 midget (1/4 – 1/3 dirt speedway). After investigating the options Honda, Toyota, Nissan, Mitsubishi etc the SR series motors seem like the the better option for my goals with it(Most are running Toyota or Honda but in my opinion they're all been building tractor motors)
Ideally I'm trying to find sources of detailed and if possible consistent research that has been done into SR20xxx heads and bottom end strengths. Almost all information I've found on the internet is say of questionable quality and is hiding I'm guessing the good work out there somewhere.
If anybody could provide me with some links to some good SR20xxx head research I'd appreciate it.
I need to narrow down the different version of heads combinations to test and cut up as there are to many to do them all. Flow bench results would be ideal but most discussions I've found don't have a degree of accuracy with methods (so making it impossible to compare between different heads).
I believe thus far I'm better off at least using the SR20VE head as a starting point(seen nothing thus far that VET head is any better and hard to locate anyway) Then on the other hand I've found manufacturers who produce roller rockers for DET heads and they are pretty much a must for high revs and aggressive cams.
I'm not leaving the head stock in the long term and will heavily port to suit; however I'm intending to keep the head near stock in initial build as there are other aspects to solve first.
For those interested in the application.
Really only the production castings and crank will be kept in the long term.(will keep sport grade pistons and rods for first “soft” build) I'll need to CNC up some rather heavy crank and cam girdles for use with second phase but that's normal. The figures below will seem rather extreme but the engines only run 4-10km per race and no certainly no more than 200km total of anger between full rebuilds.
Setup for Midget engines
Stage 1 Engine
Stage 2 Engine
I'm developing my own engine to go into a speedway F2 midget (1/4 – 1/3 dirt speedway). After investigating the options Honda, Toyota, Nissan, Mitsubishi etc the SR series motors seem like the the better option for my goals with it(Most are running Toyota or Honda but in my opinion they're all been building tractor motors)
Ideally I'm trying to find sources of detailed and if possible consistent research that has been done into SR20xxx heads and bottom end strengths. Almost all information I've found on the internet is say of questionable quality and is hiding I'm guessing the good work out there somewhere.
If anybody could provide me with some links to some good SR20xxx head research I'd appreciate it.
I need to narrow down the different version of heads combinations to test and cut up as there are to many to do them all. Flow bench results would be ideal but most discussions I've found don't have a degree of accuracy with methods (so making it impossible to compare between different heads).
I believe thus far I'm better off at least using the SR20VE head as a starting point(seen nothing thus far that VET head is any better and hard to locate anyway) Then on the other hand I've found manufacturers who produce roller rockers for DET heads and they are pretty much a must for high revs and aggressive cams.
I'm not leaving the head stock in the long term and will heavily port to suit; however I'm intending to keep the head near stock in initial build as there are other aspects to solve first.
For those interested in the application.
Really only the production castings and crank will be kept in the long term.(will keep sport grade pistons and rods for first “soft” build) I'll need to CNC up some rather heavy crank and cam girdles for use with second phase but that's normal. The figures below will seem rather extreme but the engines only run 4-10km per race and no certainly no more than 200km total of anger between full rebuilds.
Setup for Midget engines
- 2L Engine at 45 degree lean.
- Running on Methanol with Mechanical Injection
- Roller Cams and Rockers(Fixed)
- Dry Sump
- Direct drive to diff (no clutch, flywheel,gearbox etc)
Stage 1 Engine
- 12~13: Compression
- Camed for Peak Power and Torque at ~7800 and ~5500
Stage 2 Engine
- 15~16:1 Compression
- Camed for Power and Torque at ~ 9000 and ~6500
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