A65 rebuild

[MITCHELL]

Hi all, happy New year to everyone. Making a bit of progress with the engine now cases together, pistons,rings and barrel on,the crank seems a little tight, I can turn it over with pair of grips but not by hand does that seem right. There has been a lot of discussion about oil pumps over the years on the forum,the existing original looks in good condition with almost no marks on the surface of the casing but I'd be interested to get the opinions of some of you more knowledgeable members. Hopefully be dropping the engine into the frame soon before it gets to heavy, so more questions will be coming soon. Cheers Dave.

[Allan G]

Did you not check how freely the crank spun at each step?
What end float do you have on the crank?

If you loosen the crank case mounting bolts, does the crank spin?

Likewise, if you loosen the barrel mounting bolts, does the crank spin?

[MITCHELL]

Morning, I conclude from your questions that it should turn by hand, it turned on before I put the cylinder on so I'll take that off and have a look. Thanks Dave.

[DAVE BRADY]

Hi,

As it turned ok before fitting the cylinders the issue could be the resistance of the rings in the bore.  If you are turning the crank by gripping the drive side splines by hand then a fresh bore could prove difficult.  Assuming that the ring gaps are correct then it could just be a matter of wrapping a bit of rag around the crank and grip it with mole grips and then turn it about as many time as you can be bothered to.  Once you have the bottom end in the frame, fit the kickstart and have few minutes turning the crank. Once the head etc is on run in as usual.

Dave.

[MITCHELL]

Hi Dave, it does feel as if it's scraping a bit with the new rings, it's all been machined by TL engineering so I'm confident all of the tolerances are correct. I'll do as you suggest and turn it over for an hour or two and see if it frees up a bit before going any further. I'd be interested to hear your views on the oil pump if you have time,I've seen srm pumps mentioned here a few times and wondered if they are a better option of am I being to keen. Cheers Dave.

[DAVE BRADY]

Hi,

I would say that 20 mins would probably be enough and make sure there is some oil in the bore.  Running in oil is best as it allows enough lubrication whilst allowing the bedding in of the rings to the bore.
Oil pumps need to be working as best they can and the original ones are all likely to have done a few miles but can still be good enough to use.  If your budget can stretch to it then a new pump may be the way to go.  I have never fitted a new pump as I have been lucky with the ones I have.  SRM pumps seem to get the best reviews but the Hepolite branded ones also get good reviews and I think are a bit cheaper.  Does the pump you have look in good condition?
I suppose the way to look at is in relation to the cost of rebuilding an engine and how many miles you are going to do.

Dave.

[cdsdorset]

Last time i spoke to them Draganfly test run/pumped all the hepolite pumps before they shopped them.

[MITCHELL]

Hi,
The oil pump looks in good condition but having already spent about  £2500.  on parts and machining the last thing I want is for a substandard pump to cause any damage. The Speedo that came with all the parts in boxes had 49 k on it, I know the engine was rebuilt at some time but  couldn't have been run on completion because the wrong crank was used and it was to long in fact it had cracked the crank case next to the bearing so it's entirely possible that a new pump was fitted then. I've got enough to do for a bit so I'll think on it. My next question will be about the clutch so be prepared. Thanks again for all your help. Cheers Dave.

[DAVE BRADY]

Hi,

Have you stripped the pump to inspect it?  Are there any markings on it to help determine what pump you have? If it looks good without scoring in the pump body then it could be fine to use.
There have been a few threads about pumps so try a search of the Forum for more info.

Dave.

[MITCHELL]

Hi
Here,a some photos of the pump. The marks on the plate are not cut into the metal theyre just on the surface but the worm drive (I think that's what it's called) looks as if bits have broken of it. As for turning the crank it's not getting any better so I've decided to strip it back and double check everything as I go. A pain but I have a day off tomorrow. Cheers Dave.

[rhyatt]

Well the worm drive is definitely damaged, so will need replacing.
Picture 2 , can't quite make out but are the teeth on the cog damaged.
Could this restrict rotation of the crank when engaged.

[DAVE BRADY]

Hi,

Definitely damage on the worm drive, as stated, the oil pump gear also looks damaged.  Remove the other pump gears and see what they are like.
Is the crank still hard to turn now that the pump and worn drive are removed?

Dave.

[MITCHELL]

Hi
I hadn't fitted the pump so that wasn't the crank problem, I've made up my mind now I'm not happy and stripping it down tomorrow to start again paying more attention at every stage, let you know how I get on. It's all a learning curve. Cheers for your help and patience. Dave.

[chaz]

just goes to show, you cant rely on what was in before.
Ive just reassembled (dry fit) my A50 crank and cases.Ive flexi honed the new t/s bush and now happy that the crank turns by hand, the camshaft turns but is tighter, but does turn with gear on..
first attempt the crank wouldnt turn and no end float.
pulled the bearing off and checked the shim and shim cup, originally a 0.020" cup and two 0.010" shims, removed the two shims and crank turns .
I assumed after the crank had been ground they might have kissed the side face  and shims needed, but as it happened, the t/s bush wasnt in as far as could have been and needed the shims removed. now 0.0025" end float which may close a bit on torquing the case bolts up.

[MITCHELL]

Afternoon chaz, when I first stripped this engine there was damage to the cases,replaced  bushes and bearing had a regrind when I tried to reassemble it as soon as I started to tighten the cases together the crank jamed, turned out it was a 66 crank in a 64 engine and it was to long hence £2500  in machining to get the correct end float and balancing so you can see why I'm over cautious about everything.