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Mating of engine components to each other (Stroker/Valves/Vcam)

-Johnno-

By -Johnno-,
in Engines & Forced Induction

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-Johnno- Explorer

-Johnno-

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Gday guys!

 

Just a quick one, hoping to get some confirmation and information from a builder or someone much more smarter than I with regards to a build I’m doing with possibly the above mentioned parts in my RB26. 
 

I already have in relation to the build the stroker kit (Tomei RB28) that I got for a steal as well as the full Ferrea valve train setup with the +1mm OS valves.  I’ve now been given the opportunity to buy a HKS Vcam Step 2 system for again a very good price and I’m incredibly keen.  Before I go ahead and drop the money I’d just like to know if there are any conflicting issues with any of the above gear when it comes time to getting the engine actually built?  I know the Step 2 Vcam requires pistons with the valve recesses, but is there any issue mating both the Vcam system and the Tomei pistons with the valve recesses all together with the oversized Ferrea valves?

 

If anyone could give me a straight answer on this or point me in the right direction I’d truly appreciate it.  I’ve done a boatload of reading but haven’t come up with a conclusive answer as of yet unfortunately. 
 

Cheers, have a rad day!
 

 

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burn4005 Proficient

burn4005

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You need 6.7mm of valve clearance at TDC.

 

Easiest is to determine if you have this after assembly but quite a waste of time..

IF you did your trigonometry at school and have the piston information and valve angle then you should be able to work it out.

Ie put the head on a bench and measure relief to deck height, then do the same for the block to piston and add the gasket thickness.

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-Johnno- Explorer

-Johnno-

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Thanks for the reply Burnie, although it’s all a little over my head.  I should’ve paid a bit more attention during maths half a lifetime ago in school, hey?

 

I think I’ll just have to risk it.  If push comes to shove there’ll probably be either some below cost brand new valves, pistons or Vcam setup depending on what works and doesn’t work. 

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Ben C34 Grand Master

Ben C34

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On 7/17/2021 at 5:25 PM, -Johnno- said:

Thanks for the reply Burnie, although it’s all a little over my head.  I should’ve paid a bit more attention during maths half a lifetime ago in school, hey?

 

I think I’ll just have to risk it.  If push comes to shove there’ll probably be either some below cost brand new valves, pistons or Vcam setup depending on what works and doesn’t work. 

huh? if you dont have enough clearance you get the pistons machined. You dont buy new pistons or valves.

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  • 9 months later...
DiscardTheWeak Enthusiast

DiscardTheWeak

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On 7/16/2021 at 8:42 AM, -Johnno- said:

Gday guys!

 

Just a quick one, hoping to get some confirmation and information from a builder or someone much more smarter than I with regards to a build I’m doing with possibly the above mentioned parts in my RB26. 
 

I already have in relation to the build the stroker kit (Tomei RB28) that I got for a steal as well as the full Ferrea valve train setup with the +1mm OS valves.  I’ve now been given the opportunity to buy a HKS Vcam Step 2 system for again a very good price and I’m incredibly keen.  Before I go ahead and drop the money I’d just like to know if there are any conflicting issues with any of the above gear when it comes time to getting the engine actually built?  I know the Step 2 Vcam requires pistons with the valve recesses, but is there any issue mating both the Vcam system and the Tomei pistons with the valve recesses all together with the oversized Ferrea valves?

 

If anyone could give me a straight answer on this or point me in the right direction I’d truly appreciate it.  I’ve done a boatload of reading but haven’t come up with a conclusive answer as of yet unfortunately. 
 

Cheers, have a rad day!
 

 

This is exactly the same question I have more my build as well. HKS 2.8, VCAM and +1 valves. Very interested to know how it worked out for you. I know Step 2 VCAM requires piston relief cuts, however, will the relief cuts that piston manufacturers do work with oversized valves? Its certainly a good question, and probably a common combination these days

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Piggaz Grand Master

Piggaz

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Really, no one can tell you. You have to measure it up as there are too many unknowns and variables.

- are there oversized valves? What size?

- has the head been decked? If so, by how much?

- has the block been decked? If so, by how much?

- head gasket thickness?

- rod to stroke ratio affects where the piston is the bore to the relation of the crank. 

- dome height of pistons

- valve relief? How deep?

So many variables the only way to know is to do it the hard way and measure it up. ANYTHING else is a guess at best. It is a expensive mistake if it’s ‘just’ off.

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GTSBoy Grand Master

GTSBoy

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Again, I can't believe that these threads exist. Back in the 1930s, when someone wanted to find out if the valves on their DOHC Peugeot Grand Prix car would hit the pistons when they advanced the cam timing 3°, they would dummy assemble the engine and find out.

Nothing has changed! Except the recipe book modifying scene.

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niZmO_Man Grand Master

niZmO_Man

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On 07/05/2022 at 6:36 AM, Dose Pipe Sutututu said:

2JZ 500kW on E85 with just studs and you can even bang the limiter all night. Can't do that with a RB without blowing apart  things.

C'mon dude, I expected more BMW from you. B58/S58 with like 500 kWrW

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