Cylinder Head Removed
#61
Former Moderator
In my area none of the machine shops can hone a FRM bore correctly. They have and equally bad time trying to correctly bore and hone a bore smaller than 4" Domestic iron V8's don't have the same piston to cylinder wall clearances a Honda does.
It is very easy to make a previously round bore egg shaped with hone, and they only way to fix it is to overbore and hone again.
It is very easy to make a previously round bore egg shaped with hone, and they only way to fix it is to overbore and hone again.
#62
Originally Posted by marcucci,Dec 31 2009, 05:35 AM
Have you ever looked at the Honda piston-to-wall clearance spec, or honing procedure? ...
@Chris: because of the hard surface I don't think that an flex hone tool will be able to even scratch on the surface. In bad case the tool will be abrased on the cylinderwalls and these particles can contaminate the oil.
marcucci, you recommend honing in this post:
If you don't hone the block, don't expect new rings to seal any better than the old ones. Also don't expect the bottom end to last very long before you end up with more blowby.
You've made conclusions and recommendations in this thread very quick. I would wait for the result of tests and the measurements. No one can evaluate a cylinder only from looking at pics.
The rings are doing 80% of the seal between piston and wall. For sure new rings can do the job! But it depends on the wear of the cylinder wall. If (! - depending on the measure) the cylinder walls are still in a constant diameter it is an indicator of the wear. When the rings are much more durable than the cylinder material, they will wear the cylinders. This can be seen in different diameters of the cylinder from top to bottom. If the cylinder surface is harder and the rings are the weakest part, than they will wear. They will twist in their grooves, the ring strenght is not sufficient to seal anymore and the shape of the rings are rounded. Finally the ring gap is too large which causes blowby.
#63
Registered User
Sorry, whenever I mention "honing" WRT Hondas (all I work on) I mean a proper bore/hone using Honda procedures and specs (proper stones, process, and clearances). I should have been more specific, or at least not used the term "hone" by itself. Sorry about that!
I still hold that re-ringing on a Honda, unless it's virtually new (in which case you probably wouldn't disassemble it) is a bad idea. I've got a motor in the shop right now that at ~56k mi has no hone marks left and looks as glazed as a 100k mi motor that's also in the shop, about to be sent out for a proper bore/hone.
I agree with you on quick conclusions, but if the head testing is to be trusted, there has to be an issue with the block. I'm sure SpitfireS is smart enough to not come here looking for his engine diagnosis, but rather suggestions as to what to do. I'm only rendering my opinion based on what I've seen.
I personally would have gotten a second opinion on the head, and I would have instructed the shop to not do any actual work on the head (like resurfacing). I'd also have the block properly measured, but I'll say again, from experience, you can't go hone bores with a simple (proper) hone and still meet the clearance spec, any S2k with 50k mi on it or more is probably egged, you can't hone from B to A pistons successfully, re-ringing without honing will deliver poor results (maybe no better than he is at now), and boring/honing to the OS pistons is likely the only course that will provide a positive outcome for SpitfireS now. This has been my experience, and I'll stick to that recommendation. But that's all that it is. For all SpitfireS knows, I'm no more credible than some dork that tells him that he can install some Prelude pistons and be fine.
Slowsk, I too have gone through a lot of shops only to find they can't do FRM. I'd recommend to ANYONE that if your shop looks at you funny, or you get a "yeah, yeah, we can do it" then you need to run and find another shop. Honda FRM motors don't offer more than one overbore piston size. And only Mahle Gold Series (Mahle makes most OE Honda pistons) work properly with FRM blocks, and they only make Gold series pistons for the H22A. So if you have an F2xC and you overbore- you only get one shot at it. Nothing pisses me off more than having a machine shop dick up a block and render it useless. Especially on an F20C where the blocks aren't cheap or easy to come by.
I've found ONE shop in the entire D/FW metroplex area that can repeatably machine FRM blocks. And they are damn good at it, and happen to be one of the best kept secrets in the industry.
I would recommend shipping the block to be machined if you can't find a good shop to do FRM blocks locally.
I still hold that re-ringing on a Honda, unless it's virtually new (in which case you probably wouldn't disassemble it) is a bad idea. I've got a motor in the shop right now that at ~56k mi has no hone marks left and looks as glazed as a 100k mi motor that's also in the shop, about to be sent out for a proper bore/hone.
I agree with you on quick conclusions, but if the head testing is to be trusted, there has to be an issue with the block. I'm sure SpitfireS is smart enough to not come here looking for his engine diagnosis, but rather suggestions as to what to do. I'm only rendering my opinion based on what I've seen.
I personally would have gotten a second opinion on the head, and I would have instructed the shop to not do any actual work on the head (like resurfacing). I'd also have the block properly measured, but I'll say again, from experience, you can't go hone bores with a simple (proper) hone and still meet the clearance spec, any S2k with 50k mi on it or more is probably egged, you can't hone from B to A pistons successfully, re-ringing without honing will deliver poor results (maybe no better than he is at now), and boring/honing to the OS pistons is likely the only course that will provide a positive outcome for SpitfireS now. This has been my experience, and I'll stick to that recommendation. But that's all that it is. For all SpitfireS knows, I'm no more credible than some dork that tells him that he can install some Prelude pistons and be fine.
Slowsk, I too have gone through a lot of shops only to find they can't do FRM. I'd recommend to ANYONE that if your shop looks at you funny, or you get a "yeah, yeah, we can do it" then you need to run and find another shop. Honda FRM motors don't offer more than one overbore piston size. And only Mahle Gold Series (Mahle makes most OE Honda pistons) work properly with FRM blocks, and they only make Gold series pistons for the H22A. So if you have an F2xC and you overbore- you only get one shot at it. Nothing pisses me off more than having a machine shop dick up a block and render it useless. Especially on an F20C where the blocks aren't cheap or easy to come by.
I've found ONE shop in the entire D/FW metroplex area that can repeatably machine FRM blocks. And they are damn good at it, and happen to be one of the best kept secrets in the industry.
I would recommend shipping the block to be machined if you can't find a good shop to do FRM blocks locally.
#64
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Well I took out number 2 today and looked over the cylinder walls again. The rings are not visibly damaged, but #3 cylinder wall looks like there is a 1/2" score in it. At this point I'm gonna wait a few days and have someone more competent than myself, Honda Master Tech, come over to help out. With any luck I can find out what is wrong and get a plan to fix it.
#65
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Well the Master Tech came over tonight and took a look at everything and couldn't see any issues with parts I had. He suggested I pull the other 2 pistons and get new rod bearings and rings. We can put it all back together and try and find issues once it is running. He is guessing stuck injector, but not sure.
#66
Registered User
A stuck injector wouldn't cause cylinder leakage. That may have been caused by the head (not sure we will ever know) but if so, and the bottom end was healthy, you should have been able to put it back together.
I'm not sure why you don't want to do it, but you need to check the bore with a gauge or at least with a set of new rings per bpaspi's post above. The bore gauge is the only real way to tell if you can safely put it back together or not.
If there are any marks in the bore that are deep enough to catch a fingernail, I wouldn't just put it back together. I'll also repeat, I wouldn't recommend you re-ring, or hand-hone and re-ring, and if you machine hone I'm guessing it's going to be out of spec unless you bore and hone to the next larger piston.
Now that you've got the motor all apart, why not just take the bottom end to be inspected by a good machine shop? Ask them for measurements or ask them to check it while you're there. Your master tech should have access to all the relevant specs.
I'm not sure why you don't want to do it, but you need to check the bore with a gauge or at least with a set of new rings per bpaspi's post above. The bore gauge is the only real way to tell if you can safely put it back together or not.
If there are any marks in the bore that are deep enough to catch a fingernail, I wouldn't just put it back together. I'll also repeat, I wouldn't recommend you re-ring, or hand-hone and re-ring, and if you machine hone I'm guessing it's going to be out of spec unless you bore and hone to the next larger piston.
Now that you've got the motor all apart, why not just take the bottom end to be inspected by a good machine shop? Ask them for measurements or ask them to check it while you're there. Your master tech should have access to all the relevant specs.
#67
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If I were you I would put it back together and do a compression and leakdown test with the reconditioned head. If it passes, your done, if not you need more involved repairs.
#68
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That is the plan. I need to pull the other 2 pistons and get new rod bearings/rings, put the head on and redo the compression and leak-down. Its is hard for me to believe that the pistons magically went out of spec and/or the bore is too large now. There are no glaringly obvious problems with the block as I would assume. It seems a far cry to think that a motor went from 100% to 0% due to a bore wear issue with no scoring or other issues present? I'm left wondering if there is a bad injector that was misdiagnosed and that either compression/leak-down was not even done or done incorrectly.
#70
This is your car, your engine, you do what you think is best for you, not everybody is on the best budget, if you have someone helping you, and you think they know what they're doing, go by what they say. I doubt it's an injector tho. Put everything back together, see if it runs and skips. Let us know how you do, we'll try and help out, good luck