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RB30 Head Gasket thickness for more boost


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6 hours ago, The Bogan said:

What HP does the MPH/ET/ Weight and stuff say, those Moroso calculators are pretty accurate for a rule of thumb ball park figure...

With that ET and MPH, plus a guestimated weight of 4000 lb (1800kg), an online calculator gets 1680 hp at the fly, so after removing drive train loss of, let's say 20%, 1340 hp atw

http://www.wallaceracing.com/et-hp-mph.php

When used against the dunnydores MPH and typical weight and drive train loss of 20% the calculator is pretty close to my old boat. 

Both the above calculator and a Moroso one we used at Autotech gave typical results.

Unless they used a different Moroso calculator than what we used to get the 1900hp???

Opinions may vary 

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Hi All,

installed the camshaft in my rb30 and was in the process of installing the rockers and rocker plate. Cylinder 4,5,6 was all smooth and the plate sat flat for the rocker to bolt in, but with cylinder 1,2,3 the rocker plate doesn't sit flat ??

wngine is at TDC piston 1 and 6 are at the highest point. Do I just start to bolt the plate down apply pressure until it sits flat or do I have to rotate the crankshaft until the rocker plate sits flat? 
 

any help would be appreciated.

thanks 

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Based on that description it's hard to know what the problem is.

Tdc could be on the exhaust stroke on the compression stroke. Either way bolting down the rockers will be easy on some spots and harder on others due to some valves being open and therefore you are compressing the springs  when tightening the rockers down.

Are you using a torque wrench? Are you following the service manual?

 

 

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3 minutes ago, Ben C34 said:

Based on that description it's hard to know what the problem is.

Tdc could be on the exhaust stroke on the compression stroke. Either way bolting down the rockers will be easy on some spots and harder on others due to some valves being open and therefore you are compressing the springs  when tightening the rockers down.

Are you using a torque wrench? Are you following the service manual?

 

 

Correct, with cylinder 1,2,3 rockers are bolting down easy in some spots and not so easy in other spots. Cylinder 4,5,6 no problems!

should I do 1 full rotation on crankshaft and then try to bolt the rockers down? Or can I just put pressure on the bolts compressing the springs down? 
thanks 

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My guess is the valves are touching the pistons and by forcing it down you’re going to even more damage.

 

Turn the crank to move the pistons down the bore and then tighten down the rockers, put the cam to tdc then move the crank back to tdc 

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34 minutes ago, Ben C34 said:

You don't have a service manual?

 

It's been nearly 20 yrs since I changed a cam on an rb30.

Service manual foes say to rotate crank.

https://rb30det.com/download/r31-workshop-manual/?wpdmdl=33658&refresh=641d788a8ae221679653002

 

Thanks buddy, so I would have to rotate it 180* ? would that be from the crankshaft pulley correct?

 

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5 minutes ago, Ben C34 said:

Manual says 1 crank rotation, yep.

Isn't it half a crank rotation 180*? and then when I'm done I would do one and a half turns to put it on compression stroke TDC correct? 

F55CCB5E-0F4F-49BC-AB7E-B0802E629301.jpeg

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Okay. Bit of a problem. Cranked the car over and my oil is milky 🫣 did compression test and came up good all the cylinders were between 115-120psi. 
not losing much coolant and no bubbling or much pressure rushing out of the radiator.

im thinking maybe the turbo is blown? Can coolant leak into turbo oil drain?

should I do a coolant pressure test and see if coolant is coming out of the turbo oil drain? If yes, I'm assuming turbo needs to be rebuilt. TIA guys!

Edited by VL_Turbo
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