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[VR-VS] How to install high ratio roller rockers from MACE

Commo_Carl

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Im just running the stock motor. Was a reco from ac delco. Has been pulling super hard for a year now on 10psi. The high ratio rockers give the same kinda effect as a cam. At a portion on the price and install time.
 

yxyx64

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Im just running the stock motor. Was a reco from ac delco. Has been pulling super hard for a year now on 10psi. The high ratio rockers give the same kinda effect as a cam. At a portion on the price and install time.

aaah, I see.....maybe a little late atm but maybe investigate a future cam swap for if and when you want to tinker some more as turbo has different needs to N/A motor cam with respect to exhaust lift versus intake lift and overlap ... what I mean is I would be surprised if less intake c/f exhaust and less overlap did not get you a better bottom end and midrange for little topend change (with better economy).

If you can data log you might like to change the intake rockers only back and see if your setup likes it better or not with less intake

added later from immortality thoughts: yep saw the pedestal change in the pics and just did not go click when I wrote rocker change in above para... was too busy thinking about the massive boosted intake charge now compared with what the exhaust is doing and hoping OP will get best bang for buck for any future money spent by investigating. Good How-to though for all.
 
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Immortality

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The MACE supplied push rods are a thick wall item and certainly won't bend. On the Buick 3800 engines with 1.9 rockers you'll have a little over .500" lift depending on which model you have as there was some variation in lobe lift with the series 1 VN's having about .515" total valve lift which is the maximum you want to run on a standard engine.

One thing that is apparent is that these V6 engines like extra valve lift/valve speed. Even the Crow range of cams run only a little more valve lift then standard, I'd recommend the Comp Cams type grinds which give much more valve lift.

aaah, I see.....maybe a little late atm but maybe investigate a future cam swap for if and when you want to tinker some more as turbo has different needs to N/A motor cam with respect to exhaust lift versus intake lift and overlap ... what I mean is I would be surprised if less intake c/f exhaust and less overlap did not get you a better bottom end and midrange for little topend change (with better economy).

If you can data log you might like to change the intake rockers only back and see if your setup likes it better or not with less intake

Unfortunately the stock rockers are not compatible with the MACE rockers as they use different pedestals, but maybe a 1/2 set from mace at say 1.7 ratio might be a good test as MACE can supply any ratio from 1.6 up to about 1.98 depending on the engine.

The stock 3800 V6 engines loves boost, yes the cam may not be ideal but it's actually not to bad either, there really aren't any off the shelf type cams to suit turbo applications so a custom grind would be in order. IF it was me, i'd spec the cam to be ground with high ratio rockers in mind, if you already have rockers and intend to fit a decent cam. There really is no reason not to run up to .600" valve lift if the valve train is set up properly.

The other option is to have the stock cam re-ground to suit, Delcowizzard does this, something along the lines of 223*/223* on 115LSA, idles like a dream and makes about 450HP with a T70 turbo @ about 16psi on an otherwise stock engine, that runs 11.7sec 1/4's with a T5. IF you do get a reground cam it must be re-hardened. If this isn't done then cam lobe failure is a possibility.

Yeah just torqued them to spec. Not totally sure on the preload, Steve will be able to tell you about that. I just torqued and then felt that the push rod wasnt loose and also that the rocker arms couldnt be easily rotated.

Ideally, when you torque down the rockers, you want the valves to be closed so you will have to rotate the engine by hand a few times.
 

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The other option is to have the stock cam re-ground to suit, Delcowizzard does this, something along the lines of 223*/223* on 115LSA, idles like a dream and makes about 450HP with a T70 turbo @ about 16psi on an otherwise stock engine, that runs 11.7sec 1/4's with a T5. IF you do get a reground cam it must be re-hardened. If this isn't done then cam lobe failure is a possibility..

Geez Louise !!!!!!!! Your making me wish i still had my Ecotec. May be a good project for my midlife crisis~~~
 

MADDNE33

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Great write up mate,

One quick question im not sure if you are running a boost gauge or familiar with the amount of boost pumping threw but did you notice any loss of boost due to the increased valve lift?
 

Commo_Carl

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Nah no loss at all. It improved power quite a bit (well enough to feel it, some say you need 10%+ to feel) And yeah got a boost gauge and the EBC also reads my boost, both of which no loss at all
Great write up mate,

One quick question im not sure if you are running a boost gauge or familiar with the amount of boost pumping threw but did you notice any loss of boost due to the increased valve lift?
 

Immortality

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Great write up mate,

One quick question im not sure if you are running a boost gauge or familiar with the amount of boost pumping threw but did you notice any loss of boost due to the increased valve lift?

With a turbo set up you shouldn't see a boost loss simply because the waste gate is controlled by intake manifold vac/pressure, simply put, if you increase the engine efficiency and your engine can consume more air the waste gate will stay closed until the intake manifold pressure reaches the set pressure of the waste gate spring.
 

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What about fuel consumption, did that go up a bit with the new rockers ?
 

MADDNE33

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With a turbo set up you shouldn't see a boost loss simply because the waste gate is controlled by intake manifold vac/pressure, simply put, if you increase the engine efficiency and your engine can consume more air the waste gate will stay closed until the intake manifold pressure reaches the set pressure of the waste gate spring.


Ahhhh yes i understand know. Thanks for clearing that up. I have read alot about people putting high ration rockers onto there l67 and loosing a few psi from them
 
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