Most liked posts in thread: Sprite Race Motor Rebuild

Just got a call, turns out the rings are correct after all, the package was labelled wrong, so it's on again. I'll get them tomorrow....

 

It runs!

Boy does high compression make a difference!

We cranked up oil pressure - and at first it almost wouldn't turn over - but his carbs were leaking gas into the cylinders and once it got some lube on the rings it spun over fine - BUT - you don't want to use gasoline as a lubricant. I insisted that we pull his carbs off and put mine on. I used a shop rag to soak up all the gas in the ports - and there was quite a bit - then put my HIF44 on it and it started after it cleared out all the wet gas off the plugs.

Once running it sounded great - good oil pressure, temp held right at 180 once it warmed up - I finally convinced him to put the muffler on it so we could hear ourselves think and it actually ran better with the back pressure, smoother and it returned to idle better.

We let it run for 20 min or so to break in the cam and when he left he had a big smile on his face! He still has some work to do to install it in the racecar, and he needs to get his carbs sorted out before he tries to run it on them.

Overall, I'm pretty happy with it now myself. I'll let it cool down overnight, then retorque the head and reset the valves then he can take it home. Sorry about the poor video, I was holding my phone while adjusting the carb.....I usually have the phone in a holder.

First start of a 1275 Sprite Race Motor - YouTube

 

Well, in the past I used a chain hoist to lift the engine, but I can't do that in this shop. But to answer your questions, yes - my back appreciates the higher stance and it sure makes it easier to use now that I can use the engine hoist to lift the engine and put it into the stand. Now I'll be able to pull one out of the engine stand and put it straight into the test bed. But I have to say, a chain hoist in the right place would be easier than pushing the lift around with it's long legs getting tangled in everything, since my shop is so small and crowded.

I'm always surprised how well this little cheap welder will run a bead - I've had it for over 30 years too and all it needs is a good bottle of gas and a clean surface and it will lay down a pretty good weld. The duty cycle is pretty small but then I'm not using it to run 10ft long beads either - it's perfect for what I do.

It wasn't exactly 32 holes, either, since I drilled a 1/4" pilot hole first, then went back with the 11/32", then chamfered each hole, on both sides! What does that come to - just short of a million?

 

Not quite as strong as I was hoping, but close - wound her up to 7500!

The squeal at the end of the pull are the dyno brakes.