Hot Honing

[mactheknife]

Do shops still hot hone? I know it was the craze some time back and it seems to have dropped out of favor. Are only the guys trying to get that last 3-5hp doing it? Just curious about it and wonder what others are doing to keep the distortion down other than using deck plates.

[Ed-vancedEngines]

Hot honing is one of the several *New Tricks* that come and go. The guys who used to do it, went away from it years ago,k and the guys who have recently discovered it, to them it is the latest ring seal trick. It takes more set-up preprations, and if it actually has any benefits I am not aware of them. None of the top builders that I know have gone back to it.

There are a lot of trends that follow cycles or get newly discovered and brought back in agin. Amongst those trends are the perfect zero deck.

Who knows, maybe we are all missing the boat now by not going back to our old ways of those things we did in the 70's and went away from.

Ed

[torquer]

i had a sb chev motown block hot honed at a absorberant rate, i had a issue with cranckcase pressure with low tension rings and pulled down the eng , torque plated it and 6 strokes you couldnt see the benefit, no windows it was spotless
I think with a thick wall block like the dart & world product stuff you dont get the bore distortion like a production block. Personally myself, i wouldnt get it done again.

I think hot honing has some merit with an alloy block

[Noob]

don't tell sunnen.. they're still on that hot hone bandwagen. their seminars will praise it as the cure for some 400ci alloy block they used in testing.


I've found personally that the distortion is minimal unless it's a cheap alloy block or an open deck. inline 4 blocks such as nissan sr series engines do not have that problem until you put aftermarket sleves in them

[CNC BLOCKS]

I have posted this before the customer would feel more in his wallet then in seat of his pants.

We have no issues with ring seal in the engines we build and leak down tests are 1.5 to 2% after a season or two of running.

If I thought there was this big gain I would surly spend the extra money and step up to the bat and buy the system.

[Ed-vancedEngines]

I think it may be possible that Sunnen has newer generation employees who have now re-discovered this 35 year old , or older trick of the week.

After all, They make the equipment, they don't use it to build racing engines.

Ed

[PackardV8]

Hi, Ed,

But then, you and I are old enough to remember when torque plates, power hones, dial bore gauges and rod bolt stretch gauges were exotic high-end tools only available to a few. How many shops build performance engines without using these today?

If the hot-honing systems were universally used, the cost to the customer would be minimal, just as the examples above are today.

thnx, jv.

[Wolfplace]

Hot honing an alloy block
I have had one experience with a very good customer that had it done by a very reputable shop as the "newest" trick of the month zillion HP gain deal

Now it could very well be the person that did it had his head somewhere it did not belong when he did it but the gains were none, leakdown after a race or two was stupid bad.
I rehoned the block with my conventional old technology torque plates, he ordered new pistons,, problems solved & he ran the rest of the season as far as I know
From the looks of the cylinder wear if this had been a wet sump engine I am quite sure the outside of the engine & anything around it would not have suffered from any rust issues,,

Not saying hot honing doesn't have merit, just that apparently it is not all that easy to get it right & good old fashioned bolt on a torque plate honing still seems to get the job done pretty well.

[headman]

I have no problem with the idea of hot honing itself.

The criteria for measuring the actual finished bore size and comparing to the piston must be approached differently.

[AUTOMAN]

Air-cooled engine, esp. 2 strokes mandatory.

cliff

[mag2555]

I can fully see the benefit in a air cooled motor , but in a water cooled block there is just no way to simulate the differing expansion rates due to varying amounts of heat seen around a Bore .

[David Redszus]

Air-cooled engine, esp. 2 strokes mandatory.

cliff

The temperature distribution of a running cylinder cannot be easily emulated
while honing; even if the actual temperature were known.

[smeg]

How do you get the piston in the hole when at room temp the bore is way smaller than the piston? Tried it before.

[BradH]

Air-cooled engine, esp. 2 strokes mandatory.

cliff

How does one circulate hot liquid through an air-cooled cylinder w/ no coolant passages?

[rustbucket79]

Air-cooled engine, esp. 2 strokes mandatory.

cliff

We machine 100 or so various single/twin/etc 2 stroke, 4 stroke, air and liquid cooled cylinders a year, hone to size and let cool to room temperature then final size, seems to work well for us. Not sure how you could hang onto a 200 degree cylinder to hone it.