Our "New to Us" Winnie

[T1 Terry]

it will stay out and I'll go hybrid using the Lexus 450h engine and hybrid trans .... that two motor speed hybrid transmission on its own can develop more torque and more Kw than the V10 ..... and powered by sunshine

Time is your enemy, I feel that you seem to over look this critical point.
btw, the same sunshine pushes up the daisy's when your time has run out.

Yeah, but it won't worry me a great deal once that happens .... Margaret can use a nicely repaired and set up Winnie to bait the trap for my replacement ..... besides, I plan to live for ever, so far, so good

T1 Terry

[T1 Terry]

Something is just not right Terry!
Open a beer, sit back & take a good long look at what is happening & ask "why"?
From what you are saying, I can come up with a few reasons but you, with your past, could easily discount some or all of them but maybe come up with your ideas.
1. They installed longer stem valves.
2. They installed longer hydraulic lifters.
3. They installed different rocker or rockers.
4. Like earlier suggested.... valves sunken into head.... insert broken & dropped out?
5. ??

I'm presuming both inlet & exhaust rockers & lifters are the same in original motor?

I'm suspecting that is the case and they didn't measure the valve stem height, an essential part of building an overhead cam engine ..... that probably accounts for the USD$1,000 difference between two separate recon head suppliers, who ever did the last job would have gone for the cheapest option no doubt ..... it wasn't going to come back to bite them if they were rubbish ......

T1 Terry

[jon_d]

A stem can become effectively longer if the valve sinks into the head....


Question: Does this petrol engine that has been converted to run on gas, does it have stelite (hardened) valve seats fitted?

[T1 Terry]

A stem can become effectively longer if the valve sinks into the head....


Question: Does this petrol engine that has been converted to run on gas, does it have stelite (hardened) valve seats fitted?

Good question, well asked The previous owner didn't even know it about the previous engine work so it must have been the owner before him that had to pay the big $$ .... I would have thought that all the reco heads had Stellite valve seats for the exhaust because they are built to run unleaded fuel, not sure if the use Stellite valve seats for the inlets though, they don't suffer the heat problems the exhaust valves and seats suffer.
After July '85, just about every machine shop installed Stellite exhaust valve seat here in Australia, the US didn't fully phase out leaded fuel until '96, even though it was first introduced over there in 1970.

It is highly unlikely the intake valves are pulled up into the head, just not a common thing to happen because the intakes don't suffer the heat with a cold air intake every cycle, but the exhausts miss the flush with fuel to cool them, so that is when Stellite valves and seats are fitted.

T1 Terry

[supersparky]

Terry, are those heads cast iron or alloy?

[T1 Terry]

Alloy heads, so they come with steel seats from factory, anything built after the introduction of unleaded fuel will have hardened exhaust valve seats because the welding of the valve face to the valve seat when the lead is no longer there to coat the surfaces to stop the welding. LPG just accelerates the problem because there is no wet fuel introduced to cool the exhaust valve head, but Stellite valves and seats eliminate this problem. The other cause was not altering the ignition timing to suit LPG, up to 10* more advance at idle through to 2,500 rpm is required for LPG, but no more advance after 3,000rpm, so the general rule is 30* advance at 3,000 rpm .... this chassis was installed with LPG/petrol from new, but being a Winnebago, who knows if there was a timing map for LPG and a separate one for petrol programmed into the engine CPU and it switched between the two maps, depending on the fuel selected on the rocker switch.

Here is another You Tube video about measuring valve stem height https://www.youtube.com/watch?v=uYPCXTKD9DA

T1 Terry

[T1 Terry]

This is a strip down of an 8 cyl version of the 10 cyl eng in the motorhome. Naturally, our unit isn't supercharged, the inlet ports look to be the same, just that one is really full of muck.
You get a fair idea of just what would have to be stripped off the front of the engine to get the heads off ...... I can't see that being an in chassis type of repair .....
The cam/rocker/hydraulic lifter set up can be seen as he strips out the cams, same set up and the difference in the rocker ratio is easy to see.

Considering how poorly maintained the engine was, the bearings and crank aren't real bad, that gives me some confidence that these engines are over built, so should last the distance. The heads on our eng all have good spark plug threads, so I'm guessing our heads are the revised version and those were the first version .....

T1 Terry

[T1 Terry]

Finally got compression on No:1 cylinder, not up to the 170 psi, but enough to get the cyl to fire once it's back together and finishing the valve seating process. The three cut hardened valve seats continually reface against the valve for the service life of the engine, the added pressure of combustion against the head of the much bigger intake valve causes a better seal than the modern "beehive" springs can achieve, the days of lapping valves to reseat them went out before unleaded fuel arrived, but certainly once unleaded fuel was the norm, lapping valves into seats became frowned upon because the valve head expands more than the valve seat, so the small grooves created when valve lapping now become high spots on high spots, reducing the valve sealing area .... with no lead to fill those grooves and make a sealing surface, the valve leaks until a better seat is hammered in to the valve face .... sometimes this doesn't happen quickly enough, and a valve failure results

T1 Terry

[jon_d]

Time for an update Terry,.... it's been almost a week.

[T1 Terry]

Did thr 10 hydraulic lifters on the left hand head, had to grind 3 to get enough clearance for the valve to close and they all now have 160psi pressure .... I think the cranking speed might have been a little slower and that is why it didn't get the 170 psi the right hand bank made, but still better than they were before and all even.

The knees suffered serious after effects of the repeated jump out of the truck and the big steps to get back in, so yesterday was a total loss and today was only in the afternoon .... but I put the new EGO brush cutter together and slashed the weeds along the fence on the kitchen builder's side ... and put a good size slash in the copper pipe that supplied water to the workshop .... so that took a while to sort as well.

Depends on how the knees feel tomorrow and if Margaret wants me to go to Adelaide to check out electric bikes, as to how much further the engine reassembly progresses.
My aim is to get it started and running on petrol to see how well the top end gets oiled and how noisy the tappets will be, I still have to refit all the lifter check valves before the tappet covers can go back on ..... and I'm waiting for proper high pressure LPG hose fitting to arrive to replace barb fitting and hose clamp some twit used previously to rejoin the gas hose they cut because they couldn't get to the fitting at converter.

T1 Terry