Topic: rebuilt engine

[luss71]

i'm planning to rebuilt my engine(cb750 1974)and i would like to  know what is the best bang for the buck
the 811,836,890,915,970,1000 or 1080cc,the most important thing for me is the reliability and after performance. Most of the time i ride with my girlfriend so i want low torque,also is there big difference in price between the 836 and the 890?


                                                                              thanks

[MRieck]

If you want torque go larger(around 900cc) and keep the compresion up.

[eldar]

I would like to add a 836 or higher kit. I can get the 836 easy enough but where would I find other kits, and since I have the K8 and my motor is almost identical to the 78F, what would I need to do besides a bore for the new pistons?

[Buffo]

The more power you make the more heat you make. The more heat you make the less your engine will love you.
To keep it working the biggest thing is going to be keeping it cool. Spend Some time and look into the best ways of keeping your new plant cool. Get the best oil cooler you can afford. But don't over do it with the oil cooler, if it cools the oil to much that is bad too. Your bike is made to run at a specific temp range. keep it in this range and half of your battle is won.

Someone on this thing is selling oil pressure gauges, buy one.

Keep a close eye on your oil level. hotter engines use more oil.

Don

[Clyde]

I would go 836 mainly for the reason that  this is the biggest bore you can use without having to releeve the cylinder.
The K8 motor uses most of its parts (pistons/cam/ valves)from the F1 motor except for the carbs which are similar to the F2. It is not as powerful as the F2 motor (with the bigger valves), however it is a good base to start working with.
The 836 kit will definitely give you more torque and mid range power, but will not do much for top end unless you go with a port job and larger carbs. The stock carbs are just not big enough to take advantage of the extra cc
I guess it depends how far you want to go and how much you are willing to spend?

[luss71]

You can go this site, they have all the parts www.dynoman.net from 811cc to 1080cc!