452 replies to this topic

[ACDodd]

Yes and yes.

Ac

[JonnyAlpha]

Yes and yes.

Ac

Ok but just for my education, why are we aiming for a lower CR? Even if I fit the MG Metro CAM?

[ACDodd]

Because the fuel is worse than when the original engine was designed.

Ac

[JonnyAlpha]

Because the fuel is worse than when the original engine was designed.

Ac

 

I thought that might be the case. Thanks 

[JonnyAlpha]

Next job - clean the block inside and out, no one around here seems to have the facilities to do a full dip.

[JonnyAlpha]

Ok,

 

So this is going to be a long slow engine rebuild, but do it right, do it once.

I am going to concentrate on the short engine first.

 

Block is nearly ready for the rebore, last bit of cleaning up needed and I am probably going to soda blast it if I can get my setup working

I am about to order the pistons but as soon as the rebore is done I need to do the dry build to get the measurements for the block re-facing / skimming.

 

Dry-Build Process

Is the Dry-Build be done before the Crankshaft is re-ground/polished? And then obviously using the original bearings? What about the Big End Bearings can you do the drybuild with the old bearings?

 

If the Dry-Build needs to be done after the Crank has been Ground / Polished how do we know what Centre Maini and Main bearings? to get do they come in different sizes depending on the Crank work?

 

New Pistons / Honing

DryBuild is done with new pistons I guess otherwise it would be pointless, however do you fit the piston rings and if so should the block be honed before or after?

 

Once the DryBuild is done and the Block is re-faced, I guess the Pistons and Crank can be fitted and Torqued down but what's the best way to keep it rust free until the Head and Gearbox are bolted on?

 

Oil Galleries

I have removed the Core plugs but not the Oil Gallery plugs yet, I am about to do that to ensure all the crud is gone.

In the Bill Sollis "Ultimate Mini Engine" DVD he recommend threaded Oil Gallery Plugs - any comments on whether I need / should do this?

 

Sorry for the dumb questions.

Edited by JonnyAlpha, 03 June 2019 - 09:00 PM.

[gazza82]

To keep my part built block rust free it is liberally coated in engine rebuild grease and wrapped in clingfilm.

[Cooperman]

The 'dry-', or 'trial-build' is done with the crankshaft re-ground or micro-polishes as appropriate and with the new bearings of the correct sizes.

Some of us use 'Plastigauge' to check the bearing running clearance of the main and big-end bearings. Also check the crankshaft end float and correct this as necessary with different thickness thrust bearings.

After the trial-build you strip it all back down and have the block deck machined if necessary so that the tops of the pistons come 0.005" down from block deck level at TDC.

You don't need threaded oil gallery plugs unless the engine is going to be stripped and cleaned out regularly as on a full-on competition car.

To keep it all clean after the short engine is built, I lightly spray it with WD40 and cover it up with an old towel. 

The key to good engine building is to keep everything absolutely clean at all times.

[JonnyAlpha]

To keep my part built block rust free it is liberally coated in engine rebuild grease and wrapped in clingfilm.

 

What about the waterways? I have done a pretty good job of cleaning them but how to stop them rusting?

[JonnyAlpha]

And can anyone link any recommended wire brushes that I could put in a drill to get into the knooks and crannies of the oil galleries and waterways?

[ryomini]

Johnny where are you at now ?  All sounded pretty good so far. 

[JonnyAlpha]

The 'dry-', or 'trial-build' is done with the crankshaft re-ground or micro-polishes as appropriate and with the new bearings of the correct sizes.

Some of us use 'Plastigauge' to check the bearing running clearance of the main and big-end bearings. Also check the crankshaft end float and correct this as necessary with different thickness thrust bearings.

After the trial-build you strip it all back down and have the block deck machined if necessary so that the tops of the pistons come 0.005" down from block deck level at TDC.

You don't need threaded oil gallery plugs unless the engine is going to be stripped and cleaned out regularly as on a full-on competition car.

To keep it all clean after the short engine is built, I lightly spray it with WD40 and cover it up with an old towel. 

The key to good engine building is to keep everything absolutely clean at all times.

 

Thanks Cooperman, can you expand on how to check the main and bug end clearances? And linking back to my original question, do we hone the bores before the trial build?

When doing the trial build does the crank need to be Torqued down?

[JonnyAlpha]

Johnny where are you at now ?  All sounded pretty good so far. 

 

Slowy, slowly, nearly finished cleaned the block:

 

Went from this: 

 

Here it is after a few days in my Citric Acid solution:

 

 

 

To this:

 

 

And few ancillaries after citric acid and a clean up:

 

 

And here it is before I removed it from the donor car

 

[Cooperman]

When doing the trial build, the bores should be honed so that the piston ring gaps can be checked together with the piston fit in the bores.

I normally torque the main and big-end caps down to 80% of the final figure with the new bearings fitted and check for good smooth rotation. If the crank has been re-ground I measure the journals and ensure that they are within tolerance. If the crank has just been micro-polished measure and, if at bottom limit, use Plasti-Gauge to check the bearing clearances. Normally just accurate measuring very accurately will be sufficient.

[JonnyAlpha]

So for the Trial and Main Engine Build, there appears to be so much discussion on which Lube to use.

 

Should I use:

 

RedLine

or 

Torco

 

I also have 5 Litres of Millers 20W50, which I could use instead.

 

Ref the RedLine - I noticed this is Synthetic and the future oil going in will be Mineral, isn't it bad to mix the two? What is the Torco stuff, Mineral or Synthetic?

 

Oh and when it comes to the Cam, do I need a different CamLube such as this one?