: To Hone or not to Hone



JoeTahoe
08-21-10, 10:20 PM
In the the middle of a N*** rebuild still has cross hatches. But I dont feel wright not honeing with new rings. I see some one on here has had a smoke problem after a rebuild and someone says there is a special way to hone. I have the GM (HELM) service manuals and I can not find any thing about honeing. Thanks for any input, Joe

miwise
08-21-10, 10:51 PM
That was me that had problems. Not sure if it was the rings or the hone job. My suggestion. . .don't do it unless you have someone certified to work on these engines do the hone for you. Make sure you don't go cheap on the rings. Get oem rings.

Ranger
08-21-10, 11:16 PM
If it still has the factory hone marks, leave it alone. Why are you even replacing the rings?

JoeTahoe
08-21-10, 11:17 PM
Ordered gm rings they will be in Thurs. just trying to figure out what is so special about honeing a N***. Installing Jakes Studs and they are Huge compared to stock. The GM service manual says nothing about honeing that i can find.

JoeTahoe
08-21-10, 11:24 PM
Ranger I am replaceing all seals and gaskets and the bearings,they had a little wear and i dont think the oil had been changed on a regular pm. The air cleaner was solidly covered and the intake is full of wet carbon. So I figured while I have it apart do every thing. I still have to pull the valves and clean and check the heads out.

Ranger
08-21-10, 11:33 PM
Sounds like it is too late, but the lower ends on the Northstar's are almost bullet proof. Rings, bearings, timing chains will usually outlast the car.

The nasty wet intake is normal. It will look like that again in short order. It is a combination of EGR and PCV gases that settle out when the engine is shut down. Unlike the old carbureted intakes that had raw fuel mist flowing threw them to clean them, fuel injected intakes don't. Just the nature of the beast.

miwise
08-21-10, 11:51 PM
I wouldn't rering it. I'd replace it after my prior experience with my engine. I'm redoing it soon b/c of something being done wrong. I would hate to see you go through the same problems that I went through. I'd love to hear how it comes out though if you continue with the rebuild. It very well could be that I used bad rings as they were made by rock products. Maybe you will have better experience with the oem rings. I'd love to hear the outcome!

N*Caddy
08-22-10, 12:08 AM
I never heard so far about anybody honing a N*, nor having problems with the rings...these things just don't go wrong even after quite a few hundred thousands miles. Well I suppose the engine was not ran without a drop of oil though.
That being said I am about to change my oil for the 4-th time in less than one month :), but I doubt anybody done that apart from me.

miwise
08-22-10, 12:23 AM
The only reason mine were replaced (at the suggestion of the guy who did the work) Was because water had infiltrated the engine creating rust on the cylinder walls and collapsing the rings. I took his suggestion and replaced them. I saw myself the result. They were rock product rings and looked as if they sprung nicely against the cylinder walls. Of course I now have a terrible smoking problem b/c the rings never sat or who knows. I believe the consensus is b/w the rings and the honing. It eats oil like its going out of style. within about 1200 miles it has consumed quite a bit of oil (I want to say a gallon but who knows for sure).

Submariner409
08-22-10, 11:00 AM
Yes, it's too late - GM does not quote honing specs because they don't want you to hone a N*. New GM low-tension rings will seal on the existing hone pattern which is a 2-stage process - part of the coarse hone is oil retention and the fine hone is compression. It's a CNC process and is hellishly difficult to do in the field - mess it up and you build an 8 cylinder oil pump. Ask miwise.

GM also now uses a new piston for complete rebuilds - it has an anti-scuff skirt application.

Same for cranks and bearings: you can't (shouldn't) turn the crank due to the recessed radius on the journal edges.

If the block was not leaking at the halfcase then it never should have been taken apart.

Vasi, If you're changing that Valvoline again, that's the fourth time in 11,000 miles of highway driving - I'll bet the oil on your dipstick - right now - is perfectly clear.

KHE
08-22-10, 11:36 AM
There is a hone spec in the manual for the Northstar engine. I don't have my manual handy but it is there. The cross hatch pattern has a specific angle and a Ra spec. The hatch angle is controlled by the rate of the hone stone in and out of the cylinder. This is a job for someone with CNC honing equipment, not some moron with a digle-berry hone and a drill motor....

miwise
08-22-10, 01:06 PM
There is a hone spec in the manual for the Northstar engine. I don't have my manual handy but it is there. The cross hatch pattern has a specific angle and a Ra spec. The hatch angle is controlled by the rate of the hone stone in and out of the cylinder. This is a job for someone with CNC honing equipment, not some moron with a digle-berry hone and a drill motor....

Yeah. I hired dingle-berry. That's exactly what he used. LOL!!!! Hard lesson to learn.

Submariner409
08-22-10, 03:20 PM
Did some snooping...........

Beginning on P. 6-328 of the 2002 GM Seville FSM is the procedure for disassembly, inspection, and cleaning of the cylinder block. There is no procedure for honing or boring the cylinders - the manual simply states that if any of the cylinders are damaged or out of spec in any dimension the block must be replaced, and the deck cannot be milled. It also states that there are no oversized service pistons available, but I think that someone makes pistons for aftermarket. SO - from several threads it appears that there are some aftermarket parts available and GM doesn't condone their use, so school is still out on the boring/honing thing. The manual does state that new rings can be fitted, but there is no mention of even a "cleanup" hone.

As an aside, the manual also talks about the rod bearing caps - from the description it sounds like these engines have cracked big end caps. Very tricky. You're supposed to replace ALL rod bolts and not reuse the old ones.

JoeTahoe
08-22-10, 11:04 PM
sub, i am gonna go with your suggestion and no hone and gm rings the rings will be here Thursday. The engine does not look that bad a very little pitting and wear on mains and rods. cylinders spec out fine and like I said there is alot of crosshatching left. I am a little old school and so is the cars owner and just thought you are there might as well do every thing. The only reason I tore it apart is it was overheating because of headgasket, half case leak and rear main leak. Chains and timing components look good. I just finished driling the block for Northstar Performance studs and I have too say that is one nice kit. I cant say enough good about that company. Need more good people like jake.
Thanks for all the input, Joe

JoeTahoe
08-22-10, 11:08 PM
The 2001 Eldorado Service manual I have says nothing about honing. Just like sub. says his does. Goes into detail about pistons, rings and cylinder wear.

miwise
08-22-10, 11:54 PM
Yeah. I think you're doing the right thing! :thumbsup:

Submariner409
08-23-10, 10:12 AM
Study the hell out of the proper piston ring install - it looks like the top compression ring is square (flat face), the second ring is the tapered oil scraper, and the oil control ring is a tricky 3-piece.

The pistons for each bank are different in the way they face - there's an ID stamp or casting in the skirt.

Buy a ring expander/install tool........and don't let the rod ends scratch the cylinder walls when you stab in the pistons.

AJxtcman
08-25-10, 09:51 PM
I own a $500 hone that runs in a drill. Yes $500
This is a Sunnen hone. I have hone only 2 Northstar blocks. I ran 500 stone on the hone.

The short skirt pistons rock in the block and make the walls wavey. Add to this carbon on the top of the piston smacking the haed and the piston is forced into the wall. The new updated coated pistons help prevent cylinder wall damage.

wavey walls are no good

http://www.goodson.com/store/product_images/AN-1129169.jpg
http://buy1.snapon.com/catalog/OBJECTS/21300/21201.JPG