Cylinder head removal 750 SF1

C

Chris750

New member
Location
Portugal
Question 1: Is it possible to remove the cyl head without removing it completely from the frame by tilting it forward?
Question 2: Is there a way to torque the inner cyl head nuts with the engine in the frame?

Cheers,
Chris
 
Piet could have put the yes as "yes".
The balance between the hassle of doing it hanging forward, against the ease with it out, I would just take it out.
I have taken the top cover off with it dropped forward to check cams or fix one tooth out bikes.
What sort of adapter spanner have you got for the torque wrench Piet?
 
if you have done all the things required to lower the engine unit forward on the two lower gearbox mounts, then you are only those two bolts from dropping the unit onto the floor, and they are even loose!

so drop it to the floor (well gently, and on a jack if you please)
CLEM
 
Yes you can as long as you got the bike propped up properly but than again all you need to do is take out 2 more bolts to pull the engine and put it on your wife's kitchen table ;o).
 
Tippie said:
Piet could have put the yes as "yes".
The balance between the hassle of doing it hanging forward, against the ease with it out, I would just take it out.
I have taken the top cover off with it dropped forward to check cams or fix one tooth out bikes.
What sort of adapter spanner have you got for the torque wrench Piet?
Click to expand...

3/8" drive "crow foot" and a modified 3/8" drive socket (stepped type, not cylindrical its entire length), either one or the other manages to snuggle over the nuts.  Still a pain...  ::)  The slight deviance caused by the crow foots' offset is easily calculated.

GT frames leave a bit more room, a bit easier there. :D

I've found the gaskets we now use at OCT have considerably less "give" than those we used prior.  When building an engine, I leave it overnight to settle and re-torque next day.  Used to be about another 30-40? rotation, next to nothing now.  After a couple of heat cycles, still next to nothing.  Seriously thinking of considering a re-torque a thing of the past!  Haven't heard of car engines requiring re-torquing for decades!

piet
 
Laverda SF said:
Piet - I always re-torque the head of a car engine after 1000 miles or less ;o)
Click to expand...

Reckon it's necessary with the old clunkers you work on Ron!

When I worked at a Toyota dealership in the late 1970s, service schedule stated re-torquing heads at first service/1000km.  Was still common practise with other marques too, even though stretch bolts were already in universal use... gasket materials and manufacturing processes have come a long way since then. 

Fresh oil all round as well at 1000km, try selling that to a car buyer today!

piet
 
sfcpiet said:
...
Fresh oil all round as well at 1000km, try selling that to a car buyer today!

piet
Click to expand...
At least some modern car manufacturers suggest (but not demand) to change the running-in oil out at 500-1000km for better engine durability. The running-in oil is some sort of light mineral oil, to run the engine in faster but not to work well on various temperatures.

Here some buyers even refuse to do that and say it's a problem for next owner. Then on winter the running-in oil gets thick and jams the engine.
 
Moto Jouni is correct in that modern car engines  have single use  stretch bolts and when removing a head new ones are needed, but the torque setting for the bolts is only a primary means of tension, in most cases that I have come across, the "tightening" is finished by rotating the bolts (in the correct order) by a measured numbers of degrees, not by torque. And on Leyland "K" series engines (eg Metro, MGF, early Freelander etc) its even more complicated, because the head bolts are one and the same as the main bearing bolts, going right down from the top of the engine and into the sump where the bearing caps are retained, take the head off and rotate the engine at your peril!, its much the same for some UJM's, now there's a term you don't here much these days, it refers to universal Japanese motor, i.e. an across the frame four.

What about modern bike engines? they don't get re-torqued after XYZ miles, so how does that work? same principal?
technology??? I like the old stuff, give me a de-coke on a single cylinder side valve any day

CLEM
CLEM
 
CLEMTOG said:
What about modern bike engines? they don't get re-torqued after XYZ miles, so how does that work? same principal?
technology???
CLEM
Click to expand...

most likely using MLS gaskets (Multi Layer Steel) and using torque to yield engine bolts

 
Clem, I have just bought a spanking new Toyota.
No attention required for 10,000 miles after driving away from the showroom, no re-torquing or oil change.

I believe modern engines are pre-thrashed at the factory to run in?
 
As Red says, modern engines have all metal head gaskets, not fibre stuff like in the olden days.
Modern longlife oil changes are a sales argument, not a proof of how good the engines are (though they certainly are in many ways). I know several workshop managers who never follow that and change their own oil at far reduced mileage. Modern cars aren?t intended to be kept for decades.
 
http://www.victorreinz.com/EN/Service-Downloads/Practical-Information/Multi-layer-Steel-MLS-Cylinder-Head-Gaskets.aspx?region

Tippie said:
Modern cars aren?t intended to be kept for decades.
Click to expand...

I'm a member on local museum vehicle club and there is a car from 1940's driven 3 000 000 kms and another car that is 100 years old. Both keep going. These new ones seem to be of bad quality :D Actually no one knows how many times these vehicles are completely rebuild and how many parts are changed from other similar vehicles, the amount is probably huge.

 
SimonR501 said:
Clem, I have just bought a spanking new Toyota.
No attention required for 10,000 miles after driving away from the showroom, no re-torquing or oil change.

I believe modern engines are pre-thrashed at the factory to run in?
Click to expand...

I believe just careful material pairing and well-calculated tolerances made possible by modern production methods are the key.

My Skoda( (puke)) Octavia 4x4 TDI daily driver is now approaching 400000km, the engine hasn't been opened (only the tappet cover to replace the injector harness and overhaul the injectors), and is still on its first clutch and generator.  Even still has the factory exhaust system after 17 years!  Unheard of 40 years ago, when the factory exhausts usually dropped off after 4 years/150000km (at least here in wet and salty Europe) and clutches and generators were dead long before...

Granted, they're not built to last forever, the makers want you to trade in your old one every 2-3 years.  But with a bit of thought and care, they do go strong for far longer than they used to!  The Octavia has been a faithful companion, requiring only consumables (apart from accident repairs) to keep it running.  Only thing that really went tits up was an indicator relay and an ABS sensor quite early on, and the water pump at 350000km, but that was only because I did not follow the factories advice of renewing it with every timing belt swap.  It managed almost 4 times what it was built for before it gave up.

Overall, bloody good quality for the money!

piet
 
The problem with trying to keep modern cars running for a long time is no longer the mechanical bits (modern oils have a lot to do with that but it's just advances in technology across the board really) but the organic bits. Yes, the drivers do get old, wear out and have to be discarded and replaced periodically, but also all the rubber bits will collapse over time. There's a lot of them and some are real buggars to replace; engine mounts, suspension bushings, steering bushings, even silly things like gearshift linkage bushings. Some can be replaced with harder wearing brass or steel bushings, most work better with urethane bushings replacing the OEM rubber ones. But the time needed to replace them as they slowly reach the point where they are better if replaced (and sometimes you can't tell them until you pull them apart) is huge and cost-prohibitive if you don't have access to an automotive workshop. And that's not including tyres, hoses, belts and oil seals and the like. Any one of them is not that much of a big deal, but over time they ALL have to be replaced because the rubber gets old, they often don't wear out but still need to be replaced.
That's why most of us replace cars periodically. I had an American Acura (in reality just a mostly rebadged Honda but with a few nicer features) that I really liked, but the maintenance costs and reduced reliability had got to the point where I just couldn't afford to keep it much longer. Then my son borrowed it and took the matter out of my hands, fortunately nobody was injured but the car was gone.
Now I drive a Prius. $US3000 for a refurbed battery pack. And I change the oil myself, with full synthetic every 8000 km.

Ken
 
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