Ok. This is my engine rebuild thread. And since you people like pictures, here they are Stage 1. Strip down.
Stage 2. Case and crank check! Took the case ans crank down to The Engine Shop in Edith. Very nice chap there helped me with useful info too. Got the case back today, which needed a linebore. Crank was good and just needed a polish Nice new bearings, ready to rock! But first, need to balance the conrods next week
Stage 3 conrod balance. I was debating weather or not to do this, but after reading and some questions on here, I thought I might as well. So, I got myself some jewelers scales, and read the page on aircooltech.com, and set to work. I managed only one rod tonight, needing only to remove 1.7 grams, using a collection of files.... Some pictures... The second picture shows where I took of some material, both sides.
Rods all done! In the end I used an angle grinder. Sounds a bit drastic, but just as long as your careful. Small smooth bits, recheck on the scale. Used a small file, and some emery paper to polish it off. Photos to follow.
Are you not supposed to ballance con rods end to end and not just the overall weight ? They are also usually shot peened to relieve any stresses put it
Yep, will do the pistons too, when I get them. I have seen examples of end balance and overall balance, but I followed the guide passed to me on this forum.
Stage 4. Bottom end rebuild. New scat cam going in, so needed to grind the bolts down to clear the oil pump. And the crank goes in! This was a little fiddly, but just as long as the mark up the hole on the thrust baring with the dowel, wiggle in the others.
Some more photos Thrust bearing was very snug! But seems ok with the case joined, and only torqued down a little. With the bearing studs finally torqued down to 25ftlbs, crank still turned ok... So, o guess that a job done!
I do have a question at this stage. Case is back together, which was a bit of a job as the Thrust bearing was VERY snug. I did use loads of assemply grease too, in the journels, bearings and cam. But what I found is that the crank does turn, does not snag, but it is quite tight. Having said that, the end float is nice a free, so I dont think it's the bearings being tight, but I'm a little worried I used too much assembly grease. It was very sticky stuff! (Joe Gibbs Racing). Is it worth feeding in some oil? See if it frees up? Or is this normal? There is one engine builder on you tube that only uses engine oil when he builds the case, and that spins very freely!
I wouldn't feed any oil in at this stage... The assembly lube is a very sticky substance, adding oil at this stage would dissolve it out of where you've put it!! And it's designed to stay on the applied surfaces during the initial cranking to get oil pressure!!
Thanks Paul But I must admit I'm tempted to split the case again, see if I messed anything up. But I know what you mean, it is very sticky stuff!
How stiff is it - I see you installed the dizzy all that stuff will make it a little more resistant to turning....
Yes, dizzy is in. I can turn it with the pulley wheel, nothing catches, but just not sure what the expect to be honest.
I can tell you that if you had pinched anything then it would take a lot of effort to move Mine takes very little effort to move but all that jam on the crank (lube) isnt the same as oil so there is a little resistance.
When you get to this stage and you have to use a spanner to turn it over, you know it's too tight and needs investigating!!
Mm. Well I don't need a spanner, just put the pulley on, and turn by hand. I spoke with a local air cooled dude, and he is going to check it for me.
You're worried about that bearing? I think perhaps you always will be unless you change it. If this is you, change it now before you get any further, it's a long way back after it's built up and installed. I'm not suggesting you should change the bearing, I haven't seen the damage, but if you could feel it personally I wouldn't be happy.
