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Tech Area => General Buick Tech => Topic started by: Scoobum on September 30 2011, 11:00:13 AM

Title: Roller Cam Gurus...Step Inside
Post by: Scoobum on September 30 2011, 11:00:13 AM
My numbers matching original engine took out the cam at 35,000 miles...and the second one I installed...sh ortly thereafter. The lifter wasn't spinning at all. Both times it was the number 3 exhaust. I've had the engine freshened up with the rotating assembly balanced...and I'm not wasting anymore time/money on taking a chance on taking out another cam...as I'm betting the lifter bore is the culprit. So...what roller cam/roller lifters do you guys recommend that I could use with the stock pushrods and stock rockers.
Title: Re: Roller Cam Gurus...Step Inside
Post by: Steve Wood on September 30 2011, 11:41:25 AM
I use a billet from PTE....it came with Comp lifters....I would suggest the near zero lifters over the standard as they pump up about 6200 rpm in my car.

The cams sold by Full Throttle are similar material to factory rollers.

Some are using other brand lifters as some of the Comps were gummed up on delivery some time ago.

Ask Ed.  He went thru the process a year ago and did a lot of research or call Billy Anderson for suggestions.
Title: Re: Roller Cam Gurus...Step Inside
Post by: Scoobum on September 30 2011, 11:47:18 AM
Steve...what spec cam would you recommend with the junk I've got bolted on?
Title: Re: Roller Cam Gurus...Step Inside
Post by: Steve Wood on September 30 2011, 01:25:49 PM
typically I like 210 or 212 on the intake duration and the same, or a hair more on the exhaust for a stock block.  That way the car still has plenty of low rpm punch when on the street and does not need more converter than whatever it takes to match the turbo.  I think most of them are around .510-.520" on the lift.

The PTE cam in mine is a 210/210.  I have forgotten the lift, but, it is close to .500.  It has a very flat torque curve and runs into valve train limitation before it ever feels like it is tired of revving.   Given the limitation of the factory crank and rods, it's probably best to not push your luck into the 6000+ range too often.
Title: Re: Roller Cam Gurus...Step Inside
Post by: daveismissing on October 06 2011, 08:56:10 AM
What is the duration of a stock cam?
Title: Re: Roller Cam Gurus...Step Inside
Post by: Scoobum on October 06 2011, 09:51:02 AM
at .050 lift duration is 192/196

lift is 384/408

lobe separation is 107

overlap is 38
Title: Re: Roller Cam Gurus...Step Inside
Post by: daveismissing on October 15 2011, 08:37:07 PM
As soon as you step away from a stock cam- are you always sacrificing gas mileage?
Title: Re: Roller Cam Gurus...Step Inside
Post by: Scoobum on October 15 2011, 08:40:19 PM
22 MPG highway mileage...so I say no.
Title: Re: Roller Cam Gurus...Step Inside
Post by: Steve Wood on October 15 2011, 09:32:19 PM
Not much, unless you get radical, then the around town will go to hell, I think.  Last time I checked, I got 21 with mine...the roller

Street driven cars should err on the small side to maintain drivability.  These cars are a lot more fun when the rear tires seem to be directly in sync with your foot instead of lagging behind.  Broad torque band, low rpm bunch, tight converter...
Title: Re: Roller Cam Gurus...Step Inside
Post by: daveismissing on October 16 2011, 12:40:52 AM
22 MPG highway mileage...so I say no.

But I'm at 26-27. ( imperial)
Title: Re: Roller Cam Gurus...Step Inside
Post by: Scoobum on October 16 2011, 07:59:46 AM
LU convertor vs NL
Title: Re: Roller Cam Gurus...Step Inside
Post by: Steve Wood on October 16 2011, 09:37:17 AM
My other car gets 25 but I have seen many that struggled to get 20....25 on an open loop chip....
Title: Re: Roller Cam Gurus...Step Inside
Post by: earlbrown on October 16 2011, 02:02:00 PM
Keep in mind a longer duration cam needs more static compression to avoid being a dog.  Gas mileage at cruise is directly linked to compression/cyl pressure too.
Title: Re: Roller Cam Gurus...Step Inside
Post by: Steve Wood on October 16 2011, 08:21:31 PM
good point.  My cars both run over 9-1.  closer to 9.3 or 4.  Including the one with the stock cam.
Title: Re: Roller Cam Gurus...Step Inside
Post by: Scoobum on October 17 2011, 03:45:16 PM
Steve...how are you achieving this compression ratio?
Title: Re: Roller Cam Gurus...Step Inside
Post by: The Radius Kid on October 19 2011, 03:30:24 AM
Steve...how are you achieving this compression ratio?


He knows Chuck Norris.
Title: Re: Roller Cam Gurus...Step Inside
Post by: Steve Wood on October 19 2011, 05:13:43 PM
Precisely, me and Chuck go back to the Ranger days.

Single .019" shim, decked blocks and decked heads....
Title: Re: Roller Cam Gurus...Step Inside
Post by: Steve Wood on October 19 2011, 05:15:04 PM
http://www.vortexbuicks-etc.com/compression_ratio_calculations.htm (http://www.vortexbuicks-etc.com/compression_ratio_calculations.htm)
Title: Re: Roller Cam Gurus...Step Inside
Post by: The Radius Kid on October 19 2011, 08:12:29 PM
Precisely, me and Chuck go back to the Ranger days.

Single .019" shim, decked blocks and decked heads....

Remind me NOT to piss you off.
Title: Re: Roller Cam Gurus...Step Inside
Post by: Charlief1 on October 19 2011, 08:59:29 PM
http://www.vortexbuicks-etc.com/compression_ratio_calculations.htm (http://www.vortexbuicks-etc.com/compression_ratio_calculations.htm)

Thanks for the link Steve. If you cut .030 off the block how much more would it increase compression with Felpro 1000 gaskets?
Title: Re: Roller Cam Gurus...Step Inside
Post by: Steve Wood on October 19 2011, 11:36:56 PM
LOL..your damn calculator works as well as mine.
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