IHADAV8.com - Turbo Buick Tech, and Nonsense
Tech Area => General Buick Tech => Topic started by: dyermullet on April 20 2016, 02:42:26 PM
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I have done some searching on tb but can't find current info. Maybe we can put together good information and add it to the knowledge base below.
What are my options for going to a roller cam?
From what I can tell their are two styles of cam retention.
Ductile Roller Cam - Uses roller button and shim between front cover to get correct clearance.
Billet Roller - Uses cam retainer plate. Needs oil mod to get more oil to lube distributor gear. Needs different material gear on distributor/cam sensor.
Then their is the choice of lifters; morels, comp and others?
Is the above correct?
Do I need to be concerned about distributor gear/cam sensor gear material like on a chevy or ford?
Swap to roller cam will also require:
New Valve springs - correct spring rate
Correct length push rods - measure during assembly
Possibly Upgrade to valve train; HD rocker shafts, upgraded rocker shaft supports
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Ductile rollers use a cam button that rides on the cover stock sensor gear is fine, pretty simple install just need to measure end play and pushrod length and a good timing set for the added spring pressure.
Billet rollers need a retention plate and oiling mods to the sensor gear and a special sensor gear not really a DYI setup best done by a machinist.
I would talk to Bison on the other forum he can spec you a custom grind and set you up with all the right pieces, untouched stock heads are limited to under .500 I think .485 is max lift on the exhaust side so pay attention to that if your heads are stock.
Braces at a minimum on the rocker shafts.
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If you drill and tap for a thrust button, you'll hit water.
I've heard of people using the stock spring loaded roller button to hold roller cams in place. Never done it personally but it seems fine. Once the oil pump get loaded the cam is pushed against the block due to the bevel gears.
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I would talk to Bison on the other forum he can spec you a custom grind and set you up with all the right pieces, untouched stock heads are limited to under .500 I think .485 is max lift on the exhaust side so pay attention to that if your heads are stock.
Braces at a minimum on the rocker shafts.
I have always been told that it was usually fine to install up to 0.516" lift on stock heads with stock rocker ratios but I would always also advise that one check the clearance to the valve guide just in case your heads are the exception to the rule. That's just good engine building practice. Note, that after I originally posted this, I talked so some other people and got varying opinions with .470" being the lowest safe lift to some that stated they ahd used 0.515. Again, measure to be sure!!
I also would advise having the valve guides redone on heads that have not been redone in recent history and that would be a good time to cut the guides down a bit for future insurance/clearance.
I don't believe there is much magic in cam selection on these engines as the turbo triumphs most things when it comes to making power until you start looking for high nines. Theory be damned :)
When it comes to rollers, if you want one, this is the one that I normally tell people to try
http://www.fullthrottlespeed.com/turbo-buick-performance/engine-parts/v6-camshafts/rev-xr2-210-215-buick-hyd-roller-cam.html#product_tabs_description_tabbed (http://www.fullthrottlespeed.com/turbo-buick-performance/engine-parts/v6-camshafts/rev-xr2-210-215-buick-hyd-roller-cam.html#product_tabs_description_tabbed)
It does not hurt the low end power much given that most will have a bit more stall in the converter than normal anyway. It seems to fit with no problem and works well with stock rockers. I like the TA Performance hd rocker shafts but I have many miles on stock rocker shafts with saddles from RJC. Use studs instead of the stock rocker shaft bolts so you get plenty of thread engagement as the saddles are fairly thick.
The cam seems to be quiet for most people. Buy the rollers they sell as well.
Don't get mad if the car is not any faster than a guy with a flat tappet cam. He just has a better turbo, heads, or knows how to tune better than you! :D
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Thanks for the insight Steve. When I researched for my cam swap I was lead to believe that the intake side was fine it was the exhaust side that was tight. I didn't measure the clearance when I installed it though.
The heads I run now are ported with bigger valves and new brass guides seals on both sides and I had the pedestals machined to accept roller rockers in case I happen to stumble onto a set. There is lots of room now 😊
http://photoshare.shaw.ca/image/a/4/f/119991/camcard-0.jpg/download/
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better to be safe than sorry!
There is a lot of conflicting information out there from people that seem to be gurus...some times the same guy will post conflicting information in different posts.... :)
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If you drill and tap for a thrust button, you'll hit water.
Why/where would I drill and tap for a thrust button? Drill into front cover?
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Don't get mad if the car is not any faster than a guy with a flat tappet cam. He just has a better turbo, heads, or knows how to tune better than you! :D
Thanks Steve. The reason for roller is to replace a worn stock flat tappet not necessarily a performance increase. I would rather not risk a new flat tappet in these engines, and the zinc content in modern oil, internets myths etc etc. I save those experiments for chevys and fords.
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I updated the original post with everyone's replies. Now I have a good base to start searching for info on. I will keep updating the original post as I gather more info.
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when using a good lifter from Johnson which is hardened instead of one of those Asian pos, there really should not be a cam failure assuming the block was cleaned out and the break in was done correctly. That could be a big assumption :D
We had a bunch of them fail back when Johnson had quit making lifters in this country but they are back in business again and TA Performance sells them and I am sure others do as well....Lotsa people are afraid to take the chance, tho
I have been using Valvoline Racing oil for a long time and it is strong on zddp. In my Challenger, I am using Classic engine oil which is loaded up for high spring pressures
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I have always been told that it was usually fine to install up to 0.516" lift on stock heads with stock rocker ratios but I would always also advise that one check the clearance to the valve guide just in case your heads are the exception to the rule.
I did some checking on several heads that I had Steve and you can't run more than .490 lift, period. That's why edeLcrap has their 204/214 CAM AT .478.
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I did a search and see TurboFabricato r has stated .515 will usually clear...but again, one should always check and never assume.
My roller is only .496 but it has clearance...so perhaps, period is the wrong term? Maybe frequently, or such would be more accurate
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I decided to ask a few different people and got a few different answers...imag ine that.
The lowest I got was 0.470"
I guess there are too many variables.
First it depends on the given head as the valve guide boss can vary a bit from head to head, year to year, etc.
Then we have the type of seal being used-factory or aftermarket. This is a good place to note that you cannot use a seal on the factory exhaust valve. This is because it has an oil groove on it which will chew any seal up that is installed on it. So, if you want to use a valve stem seal on the exhaust, you have to swap the valves out for an aftermarket version-Stainless Steel should be used.
Then, it also is affected by the particular retainer being used. Some provide more clearance than others.
So, the moral is to always check the clearance as mentioned before.
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That makes sense I reused my retainers and locks just swapped to 1201 PAC springs. Not sure how the bee hive springs retainers look they seem to be what FT sell with their kits.
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Huh look what was just introduced .....
https://www.facebook.com/FullThrottleSpeed/photos/a.402243346478154.78544.112970375405454/984878924881257/?type=3
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Huh look what was just introduced .....
https://www.facebook.com/FullThrottleSpeed/photos/a.402243346478154.78544.112970375405454/984878924881257/?type=3 (https://www.facebook.com/FullThrottleSpeed/photos/a.402243346478154.78544.112970375405454/984878924881257/?type=3)
Now isn't that a cute little baby roller cam.....
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Now isn't that a cute little baby roller cam.....
That is a little one!
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I found it interesting after the discussion on how much lift could be used on untouched heads that these would be introduced.
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I looked up the stock cam specs to compare to the new full throttle stock replacement roller cam Here we go:
Stock cam: Duration @ .050 Lift at .050
intake 192 intake .384
exhaust 196 exhaust .408
lobe separation is 107 and overlap is 38
Roller 204: intake 204 intake .440
exhaust 204 exhaust .440
lobe separation is 111 and could not find overlap
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for a baby roller its still a good step up from stock nice post Jason
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So are you going to be putting the Fetis cam in?