Narley
3rd May 2005, 01:22
After much (read too much) thought. I took apart the88 inch race motor. I needed more power....who doesnt?
The idea was to lower the cylinder pressure and cr to make the motor condusive to handling nitrous.
The motor came apart and the 35 cc dome pistons and axtell iron cylinders were removed. This setup was 15-1 and produced a very high 250psi cylinder pressure. I had another set of cylinders and wiseco 12-1 pistons. They would be the major changes.( oh yeah ,and the beautiful Edelbrock nitrous kit with small jets for now).
While in the motor we found an exhaust valve would leak around the seat into the chamberwhen we filled the port with parts cleaner. That was cured. Then it was reassembled with no base gasket and an.043 head gasket. The chambers were measured (if you recall I couldnt get this figure from the builder of the motor so it had to come apart. But I am glad,cause its better to know for sure.)The chamber was 73cc. So the cr was now 11.6 to one. After reassemebly we tested the cylinder pressure and I was very glad with the 185-190 lbs results.
So now it had the new pistons and cylinders(nikasil coating really impressed my mech when he first hand turned the motor to check clearances.he said it was very easy to turn over...less friction...more power.)
It also got a new twin tec igntion so I could pc program it and use a nitrous retard .And it had a new edelbrock nitrous system with their adjustable rpm activator and limiter module. Small jets only for a few weeks then we will put in the 40/44 combo for 40-45 hp.
All went really well and I have a few hundred miles on it. I put a quick 100 miles on it after assembly and pre dyno, then we ran it. It was what I wanted. Lower cr...I even run premium pump gas and it doesnt ping...but I dont chug this thing at all trust me.
136 hp and 112 without the nitrous
http://img.photobucket.com/albums/v700/Narley/Harley%20racing/smalljetn20dynovsallmotordyno3.jpg
The idea was to lower the cylinder pressure and cr to make the motor condusive to handling nitrous.
The motor came apart and the 35 cc dome pistons and axtell iron cylinders were removed. This setup was 15-1 and produced a very high 250psi cylinder pressure. I had another set of cylinders and wiseco 12-1 pistons. They would be the major changes.( oh yeah ,and the beautiful Edelbrock nitrous kit with small jets for now).
While in the motor we found an exhaust valve would leak around the seat into the chamberwhen we filled the port with parts cleaner. That was cured. Then it was reassembled with no base gasket and an.043 head gasket. The chambers were measured (if you recall I couldnt get this figure from the builder of the motor so it had to come apart. But I am glad,cause its better to know for sure.)The chamber was 73cc. So the cr was now 11.6 to one. After reassemebly we tested the cylinder pressure and I was very glad with the 185-190 lbs results.
So now it had the new pistons and cylinders(nikasil coating really impressed my mech when he first hand turned the motor to check clearances.he said it was very easy to turn over...less friction...more power.)
It also got a new twin tec igntion so I could pc program it and use a nitrous retard .And it had a new edelbrock nitrous system with their adjustable rpm activator and limiter module. Small jets only for a few weeks then we will put in the 40/44 combo for 40-45 hp.
All went really well and I have a few hundred miles on it. I put a quick 100 miles on it after assembly and pre dyno, then we ran it. It was what I wanted. Lower cr...I even run premium pump gas and it doesnt ping...but I dont chug this thing at all trust me.
136 hp and 112 without the nitrous
http://img.photobucket.com/albums/v700/Narley/Harley%20racing/smalljetn20dynovsallmotordyno3.jpg