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While looking at some of the Performance Type IV pages, like http://www.pauter.com/ I noticed they have a set of roller rockers for their Type IV engines. I know this is a must for anyone w/ an American V8 to get more power. I was not even aware of these for Type IV. Has anyone had experience with them? Would we need to do as valve adj so often using these? Just some novice engine questions in lue of the recent threads on high performance Type IV's.
By the way I have only seen these rollers on Drag and Sand Rail cars' pages thus far...ex:Sand Rail Page Thanks for any info! Nathan Now if I could only afford the Nickies ![]()
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'73 2.0 914 (2.8 /6 conversion in progress) '64 356SC '65 Ducati Falcon 80 ‘19 Audi SQ5 |
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Location: chula vista ca usa
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As part of a full set of modifications, the roller rockers are good. By their selves, I doubt they make any difference. They are easier on big (48mm) intake valves due to the rollers and have more clearance for larger diameter/dual valve springs. They do require drilled adjuster screws and this means a lot more oil flow to the valve cover area. The increased oil flow would probably require a larger oil pump or external oil pump and a vent system to make sure the oil will get back to the sump quickly. We have had lots of troubles with pressure in the vlave covers and finally started using the CB-Performance bolt on with large vents on each cover. As for valve adjustment life I can't say as I adjust them after every race weekend. Good luck.
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Roller rockers?
Serve a couple of purposes: 1. Less side load on valves, as tip "rolls" across valve stem head rather than slides - lessens wear on guides and lessens mushrooming of valve stem head. 2. If rocker also has needle bearings, prevents galling of rocker shaft under high spring loads. Other than that, they're just expensive (but pretty)!
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"Inventor - Blue Flame 914 Seat Heater" "Yellow Rusty Cars Are Faster" _____________________________ '70 2.5 (I'll never finish it - Somewhere over the rainbow.....,) '73 2.0 (Just Not The Same) '74 2.0 (Heartless & Lungless) |
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If I recall correctly, they are also a higher ratio than the stock ~1.3 ratio rockers.
Lotsa money for very little gain. Probably should only be used if they are needed, if you're running really high RPMs and/or really need the ~1.4 (??) rocker ratio. --DD
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Pelican Parts 914 Tech Support A few pics of my car: http://www.pelicanparts.com/gallery/Dave_Darling |
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Pauter's rockers are 1.48 ratio which means if the cam has 0.450 inch lift with stock 1.1 ratio rockers, it will go up to 0.598 inch with 1.48 ratio rockers. The duration will also change and in all probability the valves will hit the pistons! The idea is to use a cam with a lower lift and easy ramp up, type 1 lifters for lightness, steel push rods, dual springs with titanium retainers and the engine can rev pretty easily. Mine does, but I tend to run it hard enough to break the valves off! I think that was due to setting valve clearances cold and the cam manufacturer said to set them hot, so now we do the adjustment hot. Hey Dave, are you going to Dunkle's this weekend? Good luck.
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Thanks for all the info guys. These things are out of my league
![]() I think I'll only go rollers if I build a big V8 for an american muscle car some time in the future. Nathan
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'73 2.0 914 (2.8 /6 conversion in progress) '64 356SC '65 Ducati Falcon 80 ‘19 Audi SQ5 |
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The ratio rockers are splash oilers, not self oilers, like stock...They should be saved for competition engines that are always turning RPM.
Most TIV cams have the wrong ramp rates for ratio rockers!
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Jake Raby Raby's Aircooled Technology http://www.aircooledtechnology.com |
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I believe that stock rockers are very close to 1.3:1 ratio. (I've also heard that the intakes and exhausts are a little different, one is just below 1.3:1 and one is just above 1.3:1 .)
I'm trying to make Dunkel's this weekend, but it's not looking very good. I've got that nasty flu that's been going around, and I'm not at all sure I'll be able to get over it enough to head down. --DD
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Pelican Parts 914 Tech Support A few pics of my car: http://www.pelicanparts.com/gallery/Dave_Darling |
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D.D.D.D. is a WUS.S.S.S.
a few 911 hot wings from Hooters will fix that flu right up!..
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Jeff turbo 914 v.2.0 |
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Jeff, please allow me to quote from the inimitable Mike Z:
"Bite me." ![]() Actually, have your sister come over and bite me!! So much for Ginter's 'cados... Unless Jenny wants to deliver 'em. --DD
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hummm, lets see, SUNNYvale Cal. no snow, no ice , no below freezing temps, why should we feel sorry for Dave???????????
Go this week end and post lots of pictures. |
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