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Proper Torque procedures RX and Apex Motors

What is the standard spec for the valve caps and the cylinder head bolts?

I have been digging in the manual but that thing is like trying to decypher some sort of code. I beleive the cam caps are 7.2 lbs?
 

a7m266d said:
What is the standard spec for the valve caps and the cylinder head bolts?

I have been digging in the manual but that thing is like trying to decypher some sort of code. I beleive the cam caps are 7.2 lbs?
Click to expand...

They give it to you in lb. ft but no torque wrench goes down that low and can be accurate, so I use an in. lb torque wrench and multiply by 12 giving you 86 inch lb. on Cam Caps.

The head bolts are all different and I don't have an manual in front of me.
You should follow Yamaha Torque specs and procedures first then go back and use my recommendation of retorque at 38 ft. lb.

Ted.
 
Hummm OK thanks Ted, I used my Snap On TQ wrench last night at 7.2 lbs but I guess it could be wrong. Damn man more tools!!!
 
As copied from the yamaha service manual

INSTALLATION
1. Install:
Gasket (cylinder head) New 1
Dowel pins 2
Cylinder head
Pass the timing chain through the timing chain
cavity.
2. Tighten:
Cylinder head nuts 1 - 10
Cylinder head bolts 11 , 12
First, tighten the nuts 1 - 10 to approximately
20 Nm (2.0 m/kg, 15 ft/lb) with a torque
wrench.
Retighten the nuts to specification torque.
Tightening steps:
Tighten the nuts 1 , 2
Nut (cylinder head):
1st 20 Nm (2.0 m/kg, 14 ft/lb)
2nd 121deg
Tighten the nuts 3 - 6 , 8 , 9
Nut (cylinder head):
1st 20 Nm (2.0 mkg, 14 ftlb)
2nd 105deg
Tighten the nuts 7 , 10
Nut (cylinder head):
1st 20 Nm (2.0 m/kg, 14 ft/lb)
2nd 140deg
Cylinder head bolts 11 , 12
Bolt (cylinder head):
12 Nm (1.2 m/kg, 8.7 ft/lb)
Apply engine oil onto the threads of the cylinder
head nuts.
Tighten the cylinder head nuts in the proper
tightening sequence as shown and torque
them in two stages.
Bolt (camshaft cap):
10 Nm (1.0 m/kg, 7.2 ft/lb)

Can't copy the picture for some reason but Yamaha's
referance numbers for head studs is as follows
Intake side from cam chain end 6mm bolt 11,9,5,1,3,7
Exhaust side from cam chain end 6mm bolt 12,8,4,2,6,10
 
a7m266d said:
Hummm OK thanks Ted, I used my Snap On TQ wrench last night at 7.2 lbs but I guess it could be wrong. Damn man more tools!!!
Click to expand...


A good general rule of thumb is to not use a torque wrench in it's lowest 20 percent of range..

Example-if it is a 0-100 lb. ft. torque wrench, do not use it in the 0-20 range. The wrench should also be recalibrated yearly.

T
 
Ted Jannetty said:
I have been recieving a lot of calls and emails regarding this so I will repost it with a few refinements.

Clean all taped holes thoroughly, apply Teflon Sealer if holes are open to coolant, or Oil if holes are blind.
Install studs hand tight.
Apply Moly lube to threads and washers both sides.
Torque using factory Proceedures and specs.
This includes the small outside bolts FACTORY SPECS.
Here is the part the makes the big difference.
Now go back in the proper sequence, One at a time, loosen the nut 1/4 turn and retorque to final spec in one motion, in this case 38 lb.ft. and 10 lb.ft.
You will see that the nut goes past where it was by up to 1/2 turn and you are not exceeding any torque values.
Never had a head gasket fail this way.

Happy Boosting.
Click to expand...

Ted. I plan on checking the torque on my head gasket in the near future so I can run 13-14 lbs of boost next season.

Do I follow your procedure, or just go to 38 lbs in one motion in the proper sequence since this is just a retorque and not a new rebuild ?

Thanks, John
 
BigDog05 said:
Ted Jannetty said:
I have been recieving a lot of calls and emails regarding this so I will repost it with a few refinements.

Clean all taped holes thoroughly, apply Teflon Sealer if holes are open to coolant, or Oil if holes are blind.
Install studs hand tight.
Apply Moly lube to threads and washers both sides.
Torque using factory Proceedures and specs.
This includes the small outside bolts FACTORY SPECS.
Here is the part the makes the big difference.
Now go back in the proper sequence, One at a time, loosen the nut 1/4 turn and retorque to final spec in one motion, in this case 38 lb.ft. and 10 lb.ft.
You will see that the nut goes past where it was by up to 1/2 turn and you are not exceeding any torque values.
Never had a head gasket fail this way.

Happy Boosting.
Click to expand...

Ted. I plan on checking the torque on my head gasket in the near future so I can run 13-14 lbs of boost next season.

Do I follow your procedure, or just go to 38 lbs in one motion in the proper sequence since this is just a retorque and not a new rebuild ?

Thanks, John
Click to expand...

ON a retorque, just go back in the proper sequence, One at a time, loosen the nut 1/4 turn and retorque to final spec in one motion, in this case 38 lb.ft. and 10 lb.ft.
You will see that the nut goes past where it was by up to 1/2 turn and you are not exceeding any torque values.
Never had a head gasket fail this way.

Ted
 
If your compression is good and you don't use coolant why in the world would you loosen the Head and re-torque?????? leave it alone!!!!!!
If you are unsure lift the head make sure everything is good and put in all new gasket and do the proper torque procedure. Don't mess with halve way.

You are just asking for trouble.......
 
powder muncher said:
If your compression is good and you don't use coolant why in the world would you loosen the Head and re-torque?????? leave it alone!!!!!!
If you are unsure lift the head make sure everything is good and put in all new gasket and do the proper torque procedure. Don't mess with halve way.

You are just asking for trouble.......
Click to expand...

This is not a question of compression, when you add a turbo your increasing cylinder pressure which pushes up on the head and will lift it off the gasket and destroy the gasket or worse.

I have found that the stock studs relax after they have been heat cycled but are more than adequet on a stock unboosted engine and will last for the life of the engine.

If you go in the retorque or retension the head stud they will hold the head down even with big boost, I have been as high as 30 psi with no issues following my recommended proceedures.

Untouched turbo or supercharged RX/Apex engines will lift the head at about 12 psi boost and the gasket will fail there are plenty of guys on here who have done just that then had to go in and change the gasket follow my procedures and now they are running well with even more boost.

If you know something I don't, please share with us and be specific.
 
so what your saying ted is when i get my cpr turbo kit this week i should do a retourque before i try to run it at stock boost
 
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