So after all that, what pistons did you end up with and what was ur final CR?

 

i think he got the same pistons i put in my motor ..

there 5cc flat tops ..

aluminum with the coating on the piston skirts ..

i put on some 67cc heads, 3cc head gasket, and 5 cc pistons .. so i got a 75 cc chamber in a 305 tpi .. so whatever that comes out to be
(around 9.3:1 i think , but dont quote me on that one)

 

My final compression ratio was the same as stock, or maybe a little bit better, but not by much. I did not end up with anything great piston wise. The shop installed stock replacement seal power pistons and ended up decking the block about 0.020" in order to bring the compression back up. At that point I was starting to run out of money, and decking the block was a bit cheaper than getting better pistons. When they tested the engine cylinder pressure, it came out to be 160 pounds in each cylinder, so I was satisfied with that.
The car seems to run very strong on the low end, and I have yet to get it past 3500 rpm. It has less than 2k miles and I am afraid to push it at least until I have put about 5K miles on it. I am afraid that I might brake something and there is still a good amount of work left to be done to the car. Among them a new paint job.
I hope to be able to get into custom prom tunning and dynoing the car after August (will be busy with school until then). I will update the post with the dyno results.
I love my new cam. The car has a bit more of an aggressive sound than it did stock. Power seems to come a little below 2k rpm and pulls hard to 3500 rpm, where I would shift and break the tires loose 1st to 2nd shifts. It used to take a bit more effort before in order for something like that to happen. I hope that the horse power is there as well.
Thanks again for the helpful suggestions provided by the members of this board.

 

Its best that you get on it every now and then right now to help set the rings much better. new motors you dont wanna baby too much for too long. Flog it abit actually helps break in the motor better and faster. I'd say your ready to drive it like you stole it at that mileage.

 

I guess I will give that a try. I have been so paranoid after my engine started knocking last time, that I have been very cautious. What do you recommend is a safe RPM to take it up to at the amount of miles the motor has on now? The guy that built the engine said that the engine is going to continue braking in until I have put about 5k mile on it. He also said that that's when I would start seeing my fuel economy start improving as well.

 

i've always heard give it 3-5K miles and baby it but its now being proven that a quicker harder running break in does much better for the motor in both power production and longevity.

i'd take it up wot from 3K rpms to 4500 or so in second gear and let off the gas letting the car in that gear to decelerate rapidly. then do it again the same way. Do that a few times and possibly change the oil. oil should look pretty clean

After that I feel that motor should be pretty much broken in. You can continue to drive it however you want after all that.

 

I have already changed the oil one time at about 800 miles. I plan on changing it again in a couple of weeks. That would be about 1000 to 1500 mi after the initial oil change. The oil looks very clean, and the car does not seem to have consumed a sip of oil during this initial period. After the second oil change, which should happen right about 2000 to 2300 miles after the rebuillt, I will drive the car for another 2000 to 2500 miles and then switch over to mobil 1 synthetic motor oil.
I will perform the acceleration / deceleration that you have suggested. How often, or how many times should I perform this procedure to set the rings?

 

a few times on one day should really hammer the rings into place. Thats how i'm gonna break in my 383. I'm gonna start it up, let it warm up and check for leaks and how smoothly the mail order base tune is, and maybe make changes if i need to, then take it for a quick short drive. vary rpms and loads, maybe drive it 10 miles. If everything is looking good, i'm gonna get on it alittle, like 50-60% throttle and decel. then 75% throttle on to about 75-80% of my peak rpm, then decel. Do that a few times work my way up to 80-90% throttle then bring her home. Let it cool, and then change the oil out. Inspect oil and filter, change over to synthetic and then go beat on it 100% throttle pass to near redline and drive it around varying rpms for another 100 miles or so, change oil and i'm done.

I'm gonna continue to look around for advice on this, but definately getting on the motor early in its life helps break it in better.