Forgive my elementary question please.

Do you cylinder hone (mostly street some strip) engines differently than (strip occasional street) engines?

~300 hone stone then plateau for street?
~600 hone stone then plateau for race?

Or is it specific per ring manufacture?

Thanks,
Karl Ellwein

 

The latter is what I think. But I'll bet there are many different opinions on this.

Rich

 

Thanks Rich,

Seems like I can't go wrong to do it as per ring manufacture specs.

So, very related to my original question....would a 600 finish hone with plateau finish finish not work well for a street engine?

Karl

 

Ring manufacturer.

Read up: http://www.babcox.com/editorial/ar/ar90058.htm

 

Thanks guys for the info and the links. I'm still trying to see if I can get a general statement from engine builders here...

Do you hone a race engine in any way differently than a street engine?

thanks,
Karl Ellwein

 

Bore geometry (size, roundness, taper) should be as good as you can (afford to) get for either street or race engine. That's the tough part, but it's JOB 1. Bore surface finish should be per the ring manufacturer's recommendation or as discussed with your block guy.

FWIW, finding an EXCELLENT block shop is not an easy task. There are some, however. If you really want the block prepped well, expect to spend over $1000.

"You don't always get what you pay for, but you RARELY get what you don't pay for." -- The Old One

 

Thanks for the info guys. I'll spend more quality time with my block guy John Brinkley.
Karl

 

The link MachinistOne posted above is a very good one. I'm familiar with all it says, and getting cylinder bores to be true cylinders, and aligned where they are supposed to be with respect to the main bearing bores just is not cheap.

If you use a boring bar which locates off the deck and centers itself in the existing bore, you don't have much assurance the bores are where they belong. That's less expensive of course than having the block CNC machined. Just measuring a bore anywhere near the accuracy discussed in the link isn't easy, nor is the equipment cheap.

I guess it depends on how good you want your engine to be. Going back to the original thread question, if you have a bore that's pretty much in the right place and relatively round, you can help it some during the honing without spending much extra. Honing doesn't correct gross shape errors, nor does it move the bores. It's sorta like bodywork and painting a car. If the bodywork isn't great, the paint job won't fix it.

What would you consider a fair price for JUST boring and honing to excellent tolerance/finish? If it's a serious power engine, you might be converting to 4-bolt steel caps. Now it gets important that these are installed, bored and align honed correctly. Here's where some of the cost occurs, but without a good job here, where everything starts, your painting over wavy sheetmetal.

My $.02

 

Good analogy!

 

There are CNC block "job shops" that can remachine a block for about the same price as a shop using BHJ fixturing. In our experience, in getting a block right there isn't a lot of cost difference between the two. IMO, that is more than 5% of the performance builds being done. Perhaps not.

Here's a shop I recommend.
http://www.cncblocksnortheast.com/

Flex hones (Brush research) aren't used to generate a bore's geometry or even size it or generate the "furrows". They are used to plateau the surface, much like a farmer flattens the tops of his plowed furrows. If you don't do all the previous steps correctly, you've wasted you money.

NASCAR dollars for block prep are in a different league from what is being discussed here, but the idea of getting the bores where they belong and as close to true cylinders as practical ($) should be basic to any serious block prep. How close? How fa$t do you want to go?

 

Gary,

FWIW to get a LT1 block preped up to around "Cup Style" standards of having everything correct it's around $2000K to do. That's putting bores, decks, mains, lifter bores, cam tunnel etc.. in the right place at the right sizes.

FWIW i've had a few blocks done with a 220/280/600 and a very light cut with the 600 at that, and they come in pretty rough on the Ra, Rz readings. Basically you just don't want to go too fine or you will have more friction and less oil on the rings since the Rz is not deep enough.

Bret