PDA

View Full Version : 8v92 Cracked head


encantotom
03-06-2009, 03:26 AM
hi all,

a week or so ago, i was putting a new starter in and while i was on the creeper under the bus, i decided to drain the airbox tank. as you know it should only have dirty yukky oil in it. much to my surprise, it was totally full of totally clean antifreeze. not a good sign. it was just inspiration i think to check it because there was no reason to.

so, i took an oil sample from the oil pan drain, and it too, had antifreeze.

i am going next week to san diego from mesa with my grandkids, so if i had not checked it and saw the antifreeze, i would have been stranded somewhere between here and sandiego with a blown motor.

the bus started and ran fine, but the coolant eats the bearings up fast. something was seriously wrong.

so i had it towed to my bus service shop where i have my major work done. they took the pan off and instantly saw the coolant in the airbox chamber for one of the cylinders on the passenger side. so they took the head off and the head was cracked. they took the cylinder liner out and the 2 "O" rings between the liner and block were pliable and not melted or burned at all. the solder plug in the airbox chamber of the head for that cylinder (which is there only as an indicator or overheating if it has been melted) was barely melted. with extreme overheating the o rings get toasted and fail. mine looked like new. i have them. in fact i will bring the piston, liner and o rings to austin for our mini ralley to show everyone how the o rings work in the wet cylinder liner. they form a coolant water jacket around the liner between it and the cylinder in the block. i knew about them, but until i saw them in the engine and the liner i didnt really understand them.

so, a new head, a new liner kit with piston for that cylinder, new rod bearings for all cylinders and new main bearings.

it was road tested today just fine and i pick it up tomorrow and will get ready to smoke my amex card.....

so it is ready for my trip next week. just have to do a few things to put things back together after the wiring job inside and fix a few little things.

dont know why the head cracked. i know it is usually from heat. the radiator looked fine and they inspected it very carefuly from the bottom hose port and there was no corrosion or build up at all. i was prepared to take it out (very very expensive) but they said i didnt need too.

i baby my coach and drive using the vmspc and have not overheated it. it had an inframe rebuild 28k miles ago by the previous owner and all i can suspect is that the head had a small crack then that got big enough recently. they said it had just happened as the rest of the cylinders were perfect. they showed them to me.

the crank also looked perfect.

this shop is very good and has been doing these old detroits for a long time and i trust them totally.

it is funny how things happen. i consider myself blessed that it didnt happen on our 7k mile trip last summer or with my grandkids in next week. it happened on a 100 mile round trip to the nascar track here.

i had them fix a few other things for me and i am excited to get going again. they said no break in was required and to drive it like i stole it....

but, i am putting in a pyrometer and dual senders for a switched digital engine temp gauge so i can monitor all that more accurately. along with my vmspc.

thanks to michael and richard for their support as i asked a zillion questions along the way the last week or so.

later

tom

encantotom
03-07-2009, 02:40 AM
hello again,

i picked up the bus today. they had taken it on two test drives and all is well. i live about 7 miles from the shop, but took a little 110 mile detour on the way home. i drove by where wally lives and picked him up and we drove up into the mountains. it was a nice drive and the newell drove like a dream.

i will check the fluids in the morning.

so, i am off to san diego on thursday for a couple of days. looking forward to the drive.

things look good and sound good so i hope all my engine problems are behind me. i asked the shop if i should do a break in period and he told me to drive it like i stole it.

so, gotta put some things back together and i am ready to cruise again.

i can tell ya you dont want to have your engine rebuilt. my credit card is still smoking....

the shop i use is very fair and great to deal with. if any of you are ever in the phoenix area, you need to use them. they are much better than traditional big coach shops.

just about every music personality has had their coaches worked on there. when i was there last nite talking to the service manager, a guy was there getting his entertainer worked on to take kenny loggins on tour.

later

tom

encantotom
03-15-2009, 10:21 AM
just finished a 850 mile weekend in the coach with the rebuilt motor. it ran like a top and had no problems.

it was fun to get out and drive her. also fun to only pay 1.78 for diesel rather than as high as 4.80 this past summer on our trip.

tom

chockwald
03-15-2009, 01:07 PM
Hey Tom....glad to hear the 8V is purring again! I totally know what you mean about the lower price of diesel.....on our June trip last year we paid over $5.00 per gallon....it is no longer painful to "fill'er up" anymore.