Has any one broke in a V1703 out of the machine? I have to retorque the head after running and this would make it lot easier? I can hook up a radiator and electric fan? As long as the flywheel is on seems that this would work. I am just finishing up a complete rebuild all new over bore.
Help Support SkidSteer Forum:
honestly, access to the head bolts isn't hard in a 743, there is enough room to pull the rocker cover off and do the bolts with the engine in the machine.
You don't really want to run the machine for 6-10 hrs without load before you do the head bolts. Just run it as normal, and do the re-torque in the machine, the engine will bed in far better
You don't really want to run the machine for 6-10 hrs without load before you do the head bolts. Just run it as normal, and do the re-torque in the machine, the engine will bed in far better
I guess your right, but I come out of drag racing. We ran engines on test stands for lots of reasons, leaks is one. Is 6 hours some thing from the manua? I was of the understanding that you get the engine up to temp for 10 min and then retorque the heads? I was also told that from a dealer? If they replace a head or gastket they are not going to pay an employee to run the machine for 6 hours or make the customer return it to the dealer after 6 hours. My understanding is the gasket is in real danger of failing until its retorqued? Does any one know where the break in procedure is after a rebuild or head gastket replacement? I am just not sure. I was an auto mechanic for Cadillac and we retorqued head bolts aftera a 1/2 hour run on such repairs on both gas and diesel enginges. I also would like to show the rebuilt engines I have running in a video to potential buyers. I also have adapters for the V2203 to a 743. That I will sell with the engines I have.
Last edited:
I work for a diesel engine rebuilder, we rebuild these engine every day. We tell every customer that we use a composite head gasket to re-tension their head bolts after 6-10 hrs of operation, be it for Kubota or Yanmar. The only one we don't touch are Shibaura/perkins as the mechanic uses a specific tensioning procedure and they are set and forget.
As for danger of failing if not tesnioned, you may get lucky and have no issues, but you have a very high chance of it leaking over time if it's not done.
At the end of the day, it's your call what you do, you may be lucky, and then you may get a slight leak that isn't an issue, then you may get enough of a leak to cause fretting of the head and block from the high pressure gas, or worst case, hydro lock and you then need new con rods or a block repair if it breaks a rod.
We wee it all.
As for danger of failing if not tesnioned, you may get lucky and have no issues, but you have a very high chance of it leaking over time if it's not done.
At the end of the day, it's your call what you do, you may be lucky, and then you may get a slight leak that isn't an issue, then you may get enough of a leak to cause fretting of the head and block from the high pressure gas, or worst case, hydro lock and you then need new con rods or a block repair if it breaks a rod.
We wee it all.
Thank you for sharing your expertise. Does any one know if there is a notice or something staing what Bobcat says about this break in period? I have been not able to find it. I would think something this important would be in print in print where?
Ok I have seen this over and over on the web: The old head haskets, after being torqued down these gaskets would tend to "settle" a bit, which made retorquing them a good idea to prevent seepage and other issues. Modern head gaskets don't have this issue and as such don't require retorquing. Now its seems some times procedures just do not change with the times and I would like to actually see somrthing current from Bobcat documentation about retorqueing head gaskets of a bobcat Mechanic who has reocuring training saying this is what we do. Some gasket manufactures now say if you retorque after breaking the gasket it will fail? If a head gasket seeps and fluid gets between the gasket and head or block its already to late the gasket has failed. So if retporquing is needed 6-10 hours seems a lot to me?
brdgbldr
Well-known member
- Joined
- Jun 1, 2012
- Messages
- 1,194
Have you tried calling a Bobcat dealer?
If the dealer is any good they will get you the info you need in the hopes that you will use them for parts and service in the future.
If the dealer is any good they will get you the info you need in the hopes that you will use them for parts and service in the future.
I'd be interested in how you go with not re-torquing it.
Note the hours on your machine and keep us informed as to how you go with it.
The idea of re-torquing the gasket is not to stop an already leaking gasket, the gasket will compress over time with heat cycles. I got a 3D84 Yanmar done at the same place i later started working. I was told to do the gasket after 6-10 hrs, i did 8 and then did the head bolts, the gasket had indeed compressed and it took a fair amount to bring it to the correct tension. It has been running great the whole time.
At the end of the day, head gaskets are cheap, so if yours fails later, they aren't expensive to replace.
Note the hours on your machine and keep us informed as to how you go with it.
The idea of re-torquing the gasket is not to stop an already leaking gasket, the gasket will compress over time with heat cycles. I got a 3D84 Yanmar done at the same place i later started working. I was told to do the gasket after 6-10 hrs, i did 8 and then did the head bolts, the gasket had indeed compressed and it took a fair amount to bring it to the correct tension. It has been running great the whole time.
At the end of the day, head gaskets are cheap, so if yours fails later, they aren't expensive to replace.
I went on the web and searched head gasket retorque. What I posted was above was al,ost word for word from the article and Ifound several. I am not saying I will not retorque my heads just that I am exploring the theory. As for a good dealer will give good info, I have found that to be very schetchy. Especially with these old bobcats. They are just replacing the engines with rebuilt more and more. I asked a mechanic about this last year and he said on the new BC we do not retorque head gaskets the gaskets do not require it the guy next to him said retorque them? Go on line and look at head gaskets for cars most say do not need retorquing? The material they use for new HG have changed. Its easy to say if the dealer is reputable they will give you good info. Sure at my cost if it is wrong. When I was at Caddillac in the 70's we were at the zone office talking about the new model in the winter. I asked what to do if they do not start, the GM instructor said the possibility of the new Caddilac model not starting in cold weather is so remote we will not waste time talking about it. I said we have 9 on the lot yeterday we cannot start so you need to come and tell the cars that! I like to see things in writing, there has to be a policy for this in a new manual some where. I know the old shop manuals say retorque but thats a 20-30 year old book.
You say the dealer says they don't re-torque head gaskets on new machines, that is because they run metal head gaskets, not composite.
The V1702/v1902 engine is not made anymore, they always ran a composite head gasket. You are comparing a caddillac, that as far as i am aware was petrol/gas to a diesel that runs wayyyy higher cylinder pressures.
The newer V2203 replacement or other 03 series engines come from the factory with a metal head gasket that you set and forget. We only put composite head gaskets on the '03 series engines if we had to skim the block more than usual and we need to maintain the correct top clearance, so we use a thicker head gasket or you need to skim the pistons.
Modern cars also run MLS head gaskets, that's why they are built and from the factory floor, they never need touching if all goes well.
But again, for a $100 head gasket, it's cheap enough to replace if it was to fail. I'd like to see how this science experiment plays out, so please do keep us informed.
The V1702/v1902 engine is not made anymore, they always ran a composite head gasket. You are comparing a caddillac, that as far as i am aware was petrol/gas to a diesel that runs wayyyy higher cylinder pressures.
The newer V2203 replacement or other 03 series engines come from the factory with a metal head gasket that you set and forget. We only put composite head gaskets on the '03 series engines if we had to skim the block more than usual and we need to maintain the correct top clearance, so we use a thicker head gasket or you need to skim the pistons.
Modern cars also run MLS head gaskets, that's why they are built and from the factory floor, they never need touching if all goes well.
But again, for a $100 head gasket, it's cheap enough to replace if it was to fail. I'd like to see how this science experiment plays out, so please do keep us informed.
