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| Mech roller lifter? https://slantsix.org/forum/viewtopic.php?t=41016 |
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| Author: | hellion_locdogg [ Mon Jul 12, 2010 8:15 pm ] |
| Post subject: | Mech roller lifter? |
Never heard any mention of them here, is there such a thing for a slant? ,Cliff |
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| Author: | emsvitil [ Mon Jul 12, 2010 9:13 pm ] |
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| Author: | DusterIdiot [ Mon Jul 12, 2010 9:40 pm ] |
| Post subject: | The long and twisty tale...the readers digest version |
If you use the search, you'll know that this is one of the myths that are kind of batted about and chased like a unicorn... Here is the reality as it is "now": 1) We can use any mechanical lifter Mopar and AMC put out as our family uses the .904 lifter bore...(we could even "sleeve" the lifter bores and use Chevy or Ford lifters for the trouble) 2) Limitation is in the "capture" gear to keep a roller lifter from turning i the bore and sliding the roller sideways and wiping out the cam lobe...unlike the "V" configuration with the open valley in the LA and B/RB blocks we have a nice "tight" little crevasse to work in, leaving little room for these devices. (Uh, yes...it's pretty tight trying to fit a 5.9L magnum capture device in there....) 3) Next limitation comes from availability of cam blanks and price for them. The Cox Brothers did a very limited run of billet cam blanks that had no provision for a oil pump/distributor gear...Last catalog I got 8 years ago listed the cam blank at $800, plus the grinding fee, plus a set of lifters and the remote oil pump and the crank trigger system leaves you in a price category similar to a well build big block (not hemi).... 4) Avenues of approach for "reasonable" priced cam blanks have come up with good ideas but as always the design falls short: a) Doc has made some cast cam blanks that are austempered, but would need machining to finish...price becomes comparible to about the billet blank, but still not too bad. b) Taking an OEM cam and having it reground can be done, but the casting is soft and it won't take the tempered roller wheel of the lifter long to ground the lobe down. c) Taking said OEM cam and having it nitrided/austempered/chromed, etc... Works in the short term, but Doc has stated that the process works but the cast material underneath is not durable and as the cast material stresses it caves away under the treated material and the lobe fails (kind of like soft ground under a highway giving out and leaving a sinkhole). Recently I did some research and the Buick GN uses the same cam blank for their mech lifters and rollers...after much footwork, the cam is ductile iron...so not the same scenario as our bumpstick material. Benefits of the roller cam theorized are: less stress on the valve train as you don't need heavy springs to keep things in line, also the lobe profile can be fairly radical to the point that "blown" engines benefit the most from the lobe being an almost " max.open and immediate shut" valve lift event, unlike the mechanical cams that slowly open and shut with their ramps, allowing some bleed out to occur at the beginning of the lobe ramp. Most modern rollers are in the .600 lift area which for even a race slant is a bit high on what the most ported head could feasibly flow. At the moment, without the $$$, this is limited to an all out drag vehicle in which $$$ can be better spent elsewhere for the power gain...Eventually someone will figure out a "treatment" for a common cam blank to make it an affordable mod, but at the moment, there just isn't one. Someday some enterprising person will work out the dynamics (similar to glueing together a hemi head), but for now we don't have this option available. Plug one into your desktop dyno and dream.... -D.Idiot |
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| Author: | hellion_locdogg [ Mon Jul 12, 2010 9:41 pm ] |
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Just a question, no need for crucifixion... lol Why do I feel like I'm opening an old can of worms? ,Cliff |
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| Author: | emsvitil [ Mon Jul 12, 2010 10:00 pm ] |
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Here ya go........ 
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| Author: | hellion_locdogg [ Mon Jul 12, 2010 10:10 pm ] |
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Hey DI, Thanks for the well explained response. Just a curious thought that crossed my mind. We must have been typing at the same time. My last post was not aimed at you, Emsviti's popcorn made me think I was in for trouble. lol ,Cliff |
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| Author: | bigall [ Tue Jul 13, 2010 2:28 am ] |
| Post subject: | mech roller lifter. |
Found this on pentastar parts in oztralia. pentastar.http://www.pentastarparts.com.au/sunsho ... il&p=811:D |
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| Author: | Charrlie_S [ Tue Jul 13, 2010 3:46 am ] |
| Post subject: | Re: mech roller lifter. |
Quote: Found this on pentastar parts in oztralia. pentastar.http://www.pentastarparts.com.au/sunsho ... il&p=811:D
That is a roller rocker set up. They are available over here from T&D machine, and RAS for much less money. At present RAS has some issues with their sets.http://www.slantsix.org/forum/viewtopic.php?t=35441 This thread was about roller lifters/cams |
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| Author: | Polara1974 [ Wed Jul 14, 2010 5:27 am ] |
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In Argentina every Slant 6 Race Engine got roller lifters/cams. I belive the roller lifters they useduring the 70/80 were manufactured by Isky, the cams were all custom gring by every Engine builder. I'll ask my engine builder about modifications to the lifter valley on the Slant to acomodate those Isky Roller Lifters. I know this for sure! |
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| Author: | maxracer21 [ Wed Jul 14, 2010 5:39 am ] |
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Please keep us posted Martin.................we gotta go to Bonneville and a roller cam is our choice of cams............ to no avail. It would be great to have your information. It could be a start at the very least. Regards, MaX |
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| Author: | Doc [ Wed Jul 14, 2010 8:42 am ] |
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Quote: In Argentina every Slant 6 Race Engine got roller lifters/cams.
Ask about the cam, what is it made of? (most roller cams are made of 8620 alloy steel)I belive the roller lifters they used during the 70/80 were manufactured by Isky, the cams were all custom ground by every Engine builder. I'll ask my engine builder about modifications to the lifter valley on the Slant to acomodate those Isky Roller Lifters. I know this for sure! Are any of the cams still available down there? DD |
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| Author: | Polara1974 [ Wed Jul 14, 2010 10:29 am ] |
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Quote: Quote: In Argentina every Slant 6 Race Engine got roller lifters/cams.
Ask about the cam, what is it made of? (most roller cams are made of 8620 alloy steel)I belive the roller lifters they used during the 70/80 were manufactured by Isky, the cams were all custom ground by every Engine builder. I'll ask my engine builder about modifications to the lifter valley on the Slant to acomodate those Isky Roller Lifters. I know this for sure! Are any of the cams still available down there? DD Most of them machined without oil pump / distributor gear or fuel pump eccentric, since they use external belt driven oil pump + distributor placed in front of the cam and electric fuel pump. I'll need a few days to find out about this, but I will for sure. Too bad I didn't saw this yesterday, since I was at Orlando's garage (my engine builder that has worked with ACTC Slants for more than 20 years). I'll also address the Oil Pump gear problem to him and see what info he has additional to the one you have here. Just be patient with me since I'll be away for two weeks! I'll keep you posted. Martin |
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| Author: | slantzilla [ Wed Jul 14, 2010 12:39 pm ] |
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The lifters aren't the issue as you can use any Mopar big block or Hemi lifter. The problem is a roller cam blank. There are a few floating around, but they are not cheap. With the small bore, rpm limit, and crappy head roller lifters are the least of your worries. 
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| Author: | DusterIdiot [ Wed Jul 14, 2010 6:44 pm ] |
| Post subject: | Addenda |
There is one more item to add in case an east coaster goes down this avenue as well...At one time ( a looong while back), a set of saddle roller cam blanks were produced. I'd have to check my notes, but I think Schnieder Cams had a couple on the shelf...As per previous conversations, this is also pretty limited as the roller lifter has a longer set of ears on it to help it center on the narrow cam lobe...as you can imagine if the cam walks a couple hundredths of an inch at high rpm the lobe and lifter impact would probably ruin the block and make a mess in the drivers shorts. Just wanted to make sure that was out there as well...since I put some research and thought into this process every so often. I would be interested to see the price on one of the Argentina blanks, it might be priced right to be able to have it sent here and machined...and still save the $$$ to put into an xDi system or something... (that and one of those large port ACTC slant heads would probably make things very "interesting")... -D.Idiot |
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| Author: | Exner Geek [ Thu Jul 15, 2010 6:40 am ] |
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I believe it is Jim Dowell at Racer Brown Cams who has the billets that DI is mentioning. They do require an unusual lifter with the guide bars on the side which hopefully he still has some of. Like most of the posters have said the possible advantages of a roller cam would be a minor enhancement to a well prepared engine. Make sure you max out all the easier stuff first. |
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