Tight Pinto!

[richies2.0gl]

I have replaced the big end bearings and piston rings in my 2.0 pinto (1976). I used a glaze buster tool that attaches to a drill to take the glaze off the bores.

I replaced all piston rings and bearings with standard items (engine had not been rebuilt before). Once assembled the engine is very tight to turn over and has a 'tight spot' when no. 2 and 3 pistons are at their peak.

I used assembly lubricant on the bearings and made sure everything was spotlessly clean before re-assembly. I have tried turing over by hand using oil and WD40 to try and free it up but I am using a 1/2" ratchet to get enough leverage to turn the engine over!

What did I do wrong? Or is there a way of bedding in the engine before I put the head on as I am sure the starter motor wont touch it once the head is back on.

Many thanks, Richie

[toohuge]

Are you sure that the all the components were replaced in the order that they were when it was running? If not, it may be worth getting some plastic gauges to measure how the bearings fit on the crank.

[richies2.0gl]

Yes, all parts were carefully put in order and assmbled with all parts going where they belonged. Yes may need to get some of those plastic guages. I take it the tight spot is a end bearing then?

[Pigeon]

Thing is to keep checking as you rebuild it that it still turns over freely. Check it before and after every operation... where "operation" includes torquing down a bearing cap... and you'll know immediately where something's wrong if it goes stiff.

Seems to me a case of taking it apart again and seeing when it frees up...

Did once have an engine that wouldn't turn over when it was all back together... big single-cylinder diesel. There wasn't anything actually wrong, it was just the combined tightness of all the new parts, it got gradually harder and harder to turn over as it went back together until when it was all complete I couldn't move it. So I made an adapter to couple a two-stroke post hole borer to the crankshaft... turned it over with that until it freed up enough to start and it then ran happily ever after. A car engine shouldn't be like that though.

[Steve_D]

If it were me I would release the big end bearing torque and leave them in place but only finger tight and see if it has freed up.
If not drop all the big ends and try just the crank.

As said before it is good practice to check for smooth movement after each stage.

Simple things to check
You did clean every scrap of carbon out of the ring grooves before fitting new rings.
You have made sure the little ears on the bearing shells are sitting correctly in the slots.
Double check the marking on the bearing shells....could be the wrong items in the packet. Ask me how I know.

Steve

[toohuge]

Yes, sorry i forgot to add, check the engine at every step and find out where it is tight. If it is tight as you are putting the pistons back in check the piston for carbon deposits in the ring slots and check that the correct rings have been fitted.

My dad had an engine that was super tight once, so he put it at the top of a hill and bump started it in reverse, not recommended.

[stevieturbo]

I built a Rover block that was very tight.....


Turned out the damn block was twisted !!!!

[anonymous-user]

richies2.0gl said:

I replaced all piston rings and bearings with standard items (engine had not been rebuilt before). Once assembled the engine is very tight to turn over and has a 'tight spot' when no. 2 and 3 pistons are at their peak.

By chance I happened to watch the Mark Evans DVD "An MG Is Born" today and he had a similar problem with the engine sticking at a certain point when turned over by hand, which turned out to be caused by one of the new crank shell bearings sitting proud by some tiny amount like 2 thou or something, so it presumably distorted once the cap was torqued up. Maybe the same can happen with piston bearings and caps?

Perhaps one of the new bearings is nipping up by a very tiny amount and causing the tight spot.

Edited by anonymous-user on Monday 13th April 19:21

[richies2.0gl]

Thank you for all your help. I did spend 2 hours cleaning all of the carbon out of the recesses in the pistons (there was some very heavy deposits in there). I will loosen all of the end caps slightly and then see if this helps. I know what you mean about sending the wrong items, I have been there many times too! To be honest it did cross my mind that Burton had sent me oversize end shells by mistake. I will have a play tomorrow and report back. Thanks again!