Honda Odyssey and Pilot Forum
General Category => Technical => Topic started by: Adnoh on July 17, 2010, 11:29:16 AM
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Well as some know I had an engine failure and though I would share the damage and rebuild with everyone.
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Time to check out the bore. The pre broke piston was in an OEM "A" bore. I have had some debt over the life of this piston as to the stock "A" bore and standard piston so heres the proff.
I did an out of round and taper test as well seen what bore th eengine willl need to go to.
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After cleaning up the jug and washing it up it does not look that bad. Looks can be deceiving though. Lets get out the bore gauge and find out.
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The bore guage does tell the story. Looks like it will need to be bored to a .25 over. The bore is past all most all of it's limits. Time to clean up the head and start collecting data for the P L A N. First the .25 over bore will be entered and the cc's of the head after its cleans and measured.
First I will collect plug data.
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A few more plug pics
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Got the plug done time to move on to the head clean up.
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It looks like the new head cc is 49 and this will be entered into the CR calculation. I will now take the old head gasket and measure it up to add to the spreed sheet for calculation. The ID of the head gasket and the crushed thickness will add cc's to the equation. The bore of the cylinder can not be used. You must use the bore of the gasket.
Also a few more head pics.
I forgot to get a pic of the gasket cross section. Sorry I will add later. I did get the Number
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I now have the gasket info to enter for a corrected CR ( compression Ratio). Recap: .25 over bore for new cylinder volume,head cc of 49, gasket #s for cc. I had a thought of coming up with a easy way to do the math for correction and computation of the numbers. SO I built a spreed sheet to enter the information and made a work book for alteration based on the base line information. The method only required the numbers already taken and the additon of piston crown cc and exhaust port height to top of cylinder. This based on using stock base gasket.
SO I need to find out for this method the cc difference between the piton dome cc and the cylinder volume for the piston crown height. In order to do this I will take a .25 over cylinder and old piston and get to work.
First: I installed a copper wire arond the piston in the ring groove to help seal and hold pistonin place for cc the cylinder.
Second: I installed the piston in the jug ( cylinder) and set the piston crown at the top of the cylinder ( deck). using a flat bar and bolting it down to the jug using the head studs and some nuts.
Third: I installed a grease seal around the piston land area ( edge of piston crown to top ring) for sealing. Usally the land area is fiquerd into the equation , however for this it is not that critucial.
Fourth: I measured the distance from piston crown edge to deck ( top of cylinder). I willuse this number to calculate the total vloume like I would do for the head gasket and get total CC's.
Fifth: I will get out the fluid and cc using the same method as I did for the head. I then will take this number and subtract it from the volume number to get a correction factor for the piston dome.
Sixth: Enter this into the spreedsheet for the calculation.
The easy method I will call it now can be done by simply mesuring the corrected swept volume of the cylinder by using the bore # and the top of ehaust to top of deck( top of cylinder). This will give me a correct swept volume in cc's and I can add the gasket, the head, total and then subtract the piston dome and use a formula to find corrected CR.
With this base information in a work book one can change the values and dial in the modafaction and tract changes in CR based on bores, head and deck numbers. If for some reson you change type of base or use spacer plate a simple change can be made to the calculate the CR effects.
I find this may be usefull for pre port and modafaction change before you blow one up. What if you run the limits of pump gas like I do It will help make slight changed to keep in check. Plus by entering the number ahead of the time you have a working guide to go by. This is just one step in the rebuild process not the only one when you go changing things. I now have a way to do pre work instead of post work modafactions, I hope.
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more pics.
Test #1 and #2 had flaws #3 was an accurate number and the one I use.
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Now I will build the excell speed sheet with the info collected.
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I tore apart the bottom end and thought I would share some pics. This is gona cost me.
I poped off the drive side case first to clean out some of the chunks as not to tare up the case bottom any more than I have to ( crank turnig with debris wedged in case) when removing atlernator parts and big ass nut.
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more pics
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more pics
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Wow...What a mess.....No case damage from all of this stuff down there bouncing around?
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Got pretty lucky. When it let go I had just opened it up off the bottom and it was turning around 7400 rpm and I heard a ting let off and hit the kill switch. It was only about a second but even at a second its Turing 123 revolutions. The crank ran around at least 100 times chewing up the parts. Just imagine the piston top separated from the rest of the piston and the combustion on the free moving piston top and than the rod slamming it back up a few times. Then the crank locking up from debris. There is some scaring in the bottom but not that bad. The cases are OK. Lucked out. The thing that concerns me more is the bearing OD in the case they show signs of spinning in the case. The drive side may need to be replaced or at least repaired. As I clean them up I will measure and see.
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Update on bottom end. The main bearings dont fit so well anymore. I measured up and dangit the cases are damaged from the spinning bearings. Working on fix. most recomend lock tight but not a big fan with that much clearence. Heres some pics/video.
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more pics.
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last pic.
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That's no good at all...A good machine man should be able to weld the bearing surfaces and mill out the openings....
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I considered welding and recutting or installing sleaves. I went up to one of the local race shops this after noon where in the past I had some work down with cases and bearing in hand. They agreed locktight bad idea for these. After discussing fixes welding ect they thought it would be best to mill out and install 7075 AL sleaves. What I discussed with them is to take stock put on lath and cut to size then mill the case to the OD and bore the sleave small. Heat the case to 400 to 450 and install the sleave for pinch fit. Then reset up the case and mill the sleave and then reheat and install the bearing. Hopfully restore factory fitment. Post up some pics when there done. I'm gona have them cut me some extras just in case I have another failure in another engine.
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I considered welding and recutting or installing sleaves. I went up to one of the local race shops this after noon where in the past I had some work down with cases and bearing in hand. They agreed locktight bad idea for these. After discussing fixes welding ect they thought it would be best to mill out and install 7075 AL sleaves. What I discussed with them is to take stock put on lath and cut to size then mill the case to the OD and bore the sleave small. Heat the case to 400 to 450 and install the sleave for pinch fit. Then reset up the case and mill the sleave and then reheat and install the bearing. Hopfully restore factory fitment. Post up some pics when there done. I'm gona have them cut me some extras just in case I have another failure in another engine.
Whats the possibility that the sleeves would fall out when the cases are heated for bearing removal/installation?How thick will they make the sleeve?
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The plan is to bore the case to 77.95 mm, to a depth of the orignal bearing pocket depth. Take the tubing and bore it to 70mm ID for the first pinch fit in the case with the OD cut on the lathe to 78mm and cut off a 19mm thick piece. Then heat up the case in an oven and place cold sleave in and let the case cool. Then set case back up and bore the sleave ID to 71.93mm. Then reheat the case, the sleave should expand at the same rate as the case and the pinch fit sleave should remain tight in the case. Then insatll bearing and let cool. The .05mm/.020 should provide a nice tight fit, I hope. I had talked to him about cutting a v notch and tig welding it in and he said not necessary that after it cooled it would not go anywere. I wish I had the skill and tools to do this myself I just no spare cases for trial and error mistakes. Plus I can not weld worth a hoot.
Thoughts. If you see something I should consider please speak up. I'm always open for sugestions.
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On another matter I started degreeing in a cylinder for the new engine. I started by meassuring it up and changing the exhaust port in prep for the the porting.
As of now I took the the cylinder from exhaust open at 92 degrees to 88.5 degrees and took the blow down to from 28 degrees to 31.5 degrees. the ex cord width from 49.98 mm to 51.99 mm or 62% to 64.85%. After the the port champher it should end up at 65%. I also took the short cylce between ports ( ex to main transfer) from 19.21mm to 18 mm. The tranfers/intake open at 120 with a 120 duration and the Ex duration to 183 degrees. The intake will change most lilkly to 119 with a 122 duration. The bore on this cylinder is at 80.16 and after working over it will have a .50 over oem cast inserted.
I'm also working over the orignal cylinder as well for an E-85 experiment. Talk aboout learing curve. This one will most likly have a wiesco in it.
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I started on the transfers changeing the roof height and angles. Heres some pics of the first go around. As of know the timing looks like EX-88,Tranfers-118 on the port openings.
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more pics
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more pics
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more pics.
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I got an old case half I will let you try if you want too....
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Is the case half salvagable. I'm taken in the cases in the morning to be done. If yours just need the main area fixed I'll be happy to have him fix it for you if mine goes ok.
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Is the case half salvagable. I'm taken in the cases in the morning to be done. If yours just need the main area fixed I'll be happy to have him fix it for you if mine goes ok.
The case I have needs the balancer bearing pocket re-worked,but the main bearing was good...I was just going to let you try one and make sure it worked before useing your good cases....You couldn't run it,with the balancer pocket damaged,but it would let you know if heat from bearing removal/install would effect the sleeve any....
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Gotcha Hoodlum. I'm pretty confident the fix is gona work and if not ohwell new engine of some type. I for sure appreiacte the offer.
Here's the port open times based on the degrees of 92/120 and 88/118. There is some pics of the hand math and an PDF file. The PDF file has the break down from 500 to 11500 rpm and is more accurate than the pics. I have it in excell if anybody want to play with the port opening in degrees.
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Adnoh
I wouldn't go and bore the cases and machine sleeves for the bearings. You need to head up to Foley Tractor and go to the parts department and order Caterpillar bearing retention compound.
When I worked for Caterpillar that is what we used. I have used it on bearings that were way looser than that and have never had any problems or failures. And it was on $20,000 cat transmissions....
That stuff has a compressive strength of like 3000 psi when cured and as long as it is applied evenly all the way around the bearing race, it will center in the case when installed.
Just a thought.......na sayers like Hoser will tell me I'm retarded but then again I'm the one with the Caterpillar experience and an engineering degree.......
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Thanks Weed, I will look into getting some. I will call the machinist and see if he had already started on them. Is there any primer required or just clean and install. What about release is it a heat release product. What about install recomendations. Install the locking agent and assembly the cases with the crank and let cure. or install bearings in cases and then let cure and pull in crank. The crank I'm installing has a run out .0005 so it pretty true.
How's work been going for you, pretty slow on my end. Went up to hutch a couple of weeks ago and my back hurt for a week. The whole place was all wooped up. Still had fun thu. Next time we go I,ll try to get ahold of ya We drive right by you place. We can stop and load you up.
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I called him and he has alredy started on them. Thanks anyway.