So,

I have some questions on honing, and I don't think anybody has covered this before.

I'm thinking about swapping my cylinder head soon for a refreshed one. I have an R53 with 170k miles on it.

Does anybody recommend honing their lower end? Has anybody done it before? When is it necessary? What things do I have to have in mind when doing this if I decide to do it? I would obviously replace the piston rings.

Thanks!

Manny

 

If you're going to the trouble of replacing the rings, I'd suggest you inspect the bores for ovality. You can do that yourself with bore gages or take it to your local machine shop. I'd recommend at least a light hone if your bores are good to remove any glaze and give your new rings a fresh surface to bed in with. Let us know what you find. I rebuilt a Toyota Twin Cam engine years ago at 160K miles and the original hone cross hatching was still visible.

 

Did this last summer. Did some engine work (rod bearings and head gasket) but found I was using tons of oil afterwards. Pulled the head again - cylinders walls were highly polished and ring gap was over 1 mm - I should have checked... So, honed the cylinders (after measuring) and replaced the rings. Oil consumption is back to normal. Compression is up. I used a ball hone and made a lot of effort to control where the abrasive laden oil went (didn't want to ruin my new rod bearings...)

 

P.s. Bought rein ring sets from ECS Tuning. $100 for all 4 cylinders

 

If you have good compression and aren't burning oil then you probably shouldn't mess with the bottom end. If you are having problems, then just pull it and do it right.

 

Thanks! I will have this in mind if I decide to dismantle my engine. The thing is, I think I'm burning quiet a bit of oil, so it makes me think that I do have glazing. I won't know until I pull the head off though. I have to make a compression test beforehand also. If it comes to that point, then I will pull the head off, replace with a thumper head and while I'm at it, hone and put new piston rings.

 

David,

Did you hone the cylinders in place, or did you take the bottom end off the car?

I'll probably be contacting you soon...maybe in a month or 2, to ask you a little bit more details. Should I replace my rod bearings?

Thanks!!!

 

Unfortunately I know I'm burning oil for a fact, don't know about the compression because I haven't performed a compression test yet. I don't want to fix what is not bad either. We all work on tight pockets sometimes.

 

A brief summary of my experience honing. This worked out fine for me; I am a fairly experienced machinist and DIYer.

I did decide to re-ring the car and replace the valve stem seals without pulling the engine.

I used ramps to get some clearance under the car and give myself a stable work environment. Drain coolant and oil, remove cylinder head (now is the time to replace those valve stem seals!). I checked the head and block with a steel straight edge and both were very flat. I cleaned both sides up with some 320 grit silicon carbide abrasive paper on a hard sanding block. Clean and clean some more... This is where patience and a carefull touch pays off. Or just take the head to a shop to machined and seals installed. My local shops weren't interested in a little job like that, so I did it myself.

Everything in the engine has a torque spec. Look them up. There are some PDF's around - the Bentley Manual does not list the internal engine torque specs.

From under the car, remove the oil pan. You can reach the connecting rods from this position and then remove the pistons. Definitely a good time to check the big-end bearing health and measure the crank connecting rod bearing diameters (measure diameter in several places to check for roundness, too). If the crank is worn or damaged, you are in for a bigger job and it is time to pull the engine... Measure the cylinder diameters in several places. If they are egg shaped or out of spec, time to pull the engine...

NOTE: The R53 engine uses under-piston oil squirters. Be VERY careful with those little nozzles. It is easy to damage them (I know first hand) and the new ones from the dealer are a little different. Since they have to be the same to balance oil-flow, I ended up replacing all 4. $120 mistake. Not the first...

It is common for cylinders to have carbon build up around the top edge of the bore - use a ridge reamer to remove this before trying to remove the piston (the piston pushes up from underneath once you have unbolted the connecting rod. Don't hammer it out... Keep your connecting rod halves together - The R53 uses cold-fractured connected rods - each one is a specially matched set and only goes back together one way.

Now you have an "empty" engine block. It gets complicated because you still have the crank in there and crank bearings you need to protect. Honing generates abrasive-filled oily mess - you MUST keep that away from your crank bearings.

I used a ball hone from "Brush Research" in my cordless drill. I choose the 79 mm diameter, 240-grit silicon carbide version ($38). Get their special flex-hone oil as it has super-duper detergents that help avoid re-depositing abrasive.

You have to keep the gritty oil away from the crank. I wandered around home depot for a while looking for something that would just fit into the 77mm cylinder bore. In the plumbing section, I found a cut-to-fit universal garbage disposal stopper. It is hard rubber with various size steps from 3.5 inches down to 2.5 inches. I trimmed this neatly so it just fit into the cylinder, I would position it with the hat shape acting like a little sump to collect oil in the center. I would work on one cylinder at a time. Stuff 2-3 clean shop rags in the cylinder to protect the crank, the rubber stopper, and then one shop rag on top as a "diaper". Hone away. Clean up all the oil, clean more, remove stopper, clean more, clean more, move to next cylinder. Plan on consuming lots of rags. I used WD-40 as my cleaning spray. There are youtube videos that show how to use those ball hones. They are supposed to be easier than the old-fashioned 3-stone hone.

Another caution - there are lots of little openings for the water jacket on the top of the engine block that will be exposed and open with the head off. You don't want to get grit or oil into there. I sealed those off and protected the top of the block with gorilla duct tape while I was working and then had to use a rag with solvent (goof-off) to remove the traces of adhesive left by the duct tape.

Good luck!

 

David,

THANKS! This some awesome info. I will obviously use this as guidance and take all the precautions that are necessary. Great guide!

R,
Manny

 

Yep , right here: ( 0 ) sized. Not plus sized.

http://www.ecstuning.com/Search/SiteSearch/11257520133/

 

I did head gasket last March (my head gasket was blown), and sent head to machine shop for planing and new guides and seals. I started burning LOTS of oil afterwards (1 qt/500 miles). I just got engine disassembled (In-Situ) and ready to hone walls. Two questions: 1). How did you keep the grinder from going too far down and hitting the little oil tubes. and 2). did you get a lot of O2 sensor codes when it was burning oil?

 

Drop the oil pan and remove the oil nozzles from underneath. You are going to want to do extensive post-honing cleaning, so you really need the pan off. I am not following your story - you had the block machined and you are now going to hone it at home? Or you only had the head machined? Having done this before, the home honing doesn't do anything to help out of round or oversized bores. If you are doing that much work, I suggest you pull the block and have it properly machined and get the next size rings and/or pistons that fit correctly and then you know its round and sized correctly...

 

No, I got the head shaved, but did nothing to the lower end, NOW, Ive pulled the head and dropped the pan and disassembled the connecting rods, pushing pistons up, to replace rings. NOW, I'll replace the the rod bearings, hone cylinders and replace rings. I'm also going to replace exhaust valves because #2 had one broken. I'm most keenly interested in torque values at this point. This engine is completely stock. I'm not building a pocket-rocket, just want a decent car that DOES NOT burn oil. So,,,,,,,,, I just need torque values for connecting rods, oil pan et al. Mod Mini has good info on putting together the head, but almost all videos I have, do not address STOCK connecting rod torque. Is there a list of torques in this forum??

 

check TIS or Bentley

 

Folks, I'm rebuilding an R53 - "stock". I marked the pistons when I took them out, and I noticed they have an "F" marked on the piston skirt. All the pistons EXCEPT #1 have the "F" mark towards the forward side of the engine (front of car), But #1 was reverse...... Ater installing the rings, should I reverse the "F" mark to face forward?? These are stock, original pistons as best as I can figure?? HELP!!

 

The rings may not even be worn out, just stuck in the grooves.

I would NOT hone the cylinders. You can really wreck power that way from increasing ring friction.
An old timer engine builder once let on to me that engines always made more power and had better ring seal on the SECOND set of rings that a given bore had... no honing.

When a successful engine builder with 40+ years of experience lets loose one of his secrets, I listen

 

Don't replace your rings before conducting both a dry and wet compression test. Your oil loss might be from bad valve seats only. The compression tests will validate this.