Serious Cams

[NixVegaGT]

That's bitchin', Jim.

GOod point, Tony. I was just ripping something from online to stimulate a response. I guess I got my wish!!

[hoffbug]

Nic..
Not trying to be a dick....Its just a relex effect of working 24 years in the pest control industry.. :-)

 I can tell you first impressions do mean something... If I see a restaurant with greasy windows and a crappy dining area I can guarantee you they dont give a rip about kitchen sanitation....

 If I see someone post an obviously crappy casting on a site that they are going to sell something that tells me something about their commitment to proper machining and QC.... Ive seen enough stuff fail over 21 years of hotrodding/drag racing... their isnt any free lunch as far as Ive ever seen.

[roverman]

Ok, "I" waz deadasleep at the engineering wheel. How would we "individually" adjust ea. lash with "no" adjuster?u-no,sbc? Mabe we could mount all the studs on a rigid plate bolted to rocker pedastles? When we consider the rocker loads of sbc's, studs should be adequate. Anybody? roverman.

[roverman]

Up-date, Doug Herbert is working up a quote for qty's: 10,25 and 50 roller cams. Lobe centers approx. 102/114deg avail.Hyd./mech. 215's through 350's. Anybody ready for serious? roverman.

[roverman]

Update, The lifter-of-choice, oem. hyd. roller may well be Buick 3.1L V6, fwd. eng. You can "peep" on the GN. V6 webb site for details. Looks similar to sbc but specific for Buicks. Perhaps this Buick lifter is convertable to mech.? At $600 from TA for V8 set of aftermarket's, this might be worth a look. roverman.

[NixVegaGT]

Ok getting closer. Here's some pix from a GN website using Chev 3.1L 60º V6 roller lifters. In this pic they are set into a 3.8L Buick:





Here's a couple comparo pix of the stock 3.8 lifter and the Chevy roller lifter. I guess the benefit is the height:




Here's an excerpt with the spec data:

The lifters out of a 1995 Chev Lumina 3.1L V-6 measure .842" wide and 2.228" high. The stock lifters are .842" wide by 2.005" high. When used with a Comp Cams 258HR (ductile iron) specs. 206/206 .498 lift, 110 LSA ......there is lots of ramp-up clearance (where the roller touches the cam,) lots of shoulder clearance top at max lift (.160" to be exact....... so the shoulder doesn't hit the dog-bones) and bottom or base circle ( .115" above flush deck....for the dog-bone retainers to stay in place) Use the retainer and bones out of a 1986 Vin "3" 3.8 roller block as shown in the photo's above (personally I would shorten the length of the spacer a little to put a little more pressure on the dog bones, but only about .200" inch less than the 1.00" suggested, you don't want too much pressure on them either)...........the only thing left to get are pushrods.

[roverman]

Good job Nic. Now I need to compare sbc,oem roller to these. Maybe there same? If so, Bingo!  =megacheep. "take-outs" are dirt cheep, so they tick?-gut-em! New ones $99(16), all day. Everbody sing..."Rollin ona River", roverman.

[BlownMGB-V8]

Just make sure the top of the "neck" and the oil hole don't uncover at full lift. One other thing, the Buick V6 may use different bore spacing that the BOP/R as it could be based on the 350. Don't know that it is, the heads are more like the 340 but you'll need to make sure because most of the rest of the engine is.

Jim

[NixVegaGT]

In the pic it looks like the guy was trying to setup the shot to compare from the bottom of the roller. It looks like the oil holes come close to matching. Your point is that maybe the other lifter's oil hole might pop out the top too, right?

My Erson solid cam's lobe lift is 340ish. Art, you're talking about making the base circle bigger and that would put the lifter higher in the bore, right?

[roverman]

Nic and clan, To my knowledge, late V6's and 350' sbb's used (1) bearing journal dia.-same as early front. This would theorectically allow .12" larger base circle over stepped design. I can't tell you if same will automatically bump the rods with 3.85" stroke. This is why I suggested "peeping" the upside-down VW style rod= waay more room at bottom of rod. We've thought about volumetric effieciency of these large strokes with,"marginal", a kind term, air flow to feed 350+ inches in na. mode? roverman.

[pcmenten]

Rolling, rolling, rollin' on a Rover.

Looks perfect. Extra lifter height to fit into the dogbones, oil hole in the right place.

Check out the spring-loaded cam button in the top picture. What is that gear on the end of the cam for?

[NixVegaGT]

That's the distributor/oilpump drive on the earlier Rover/Buick front cover. I totally missed the cam button... So if the later Buick 350 used one bearing dia. why wouldn't there be room? OH I see, you're saying if we make the base dia 1/8" bigger dia that will push the lobe out another 60 thou, right?

[roverman]

Larger base circle will make cam stronger/work the "valley" less and be less hostile to the lifters. OEM 350's/late V6's should already have larger base circle? I would think the cast iron folks would want Rover cam retention plate? roverman.

[NixVegaGT]

I think this is the rods you were talking about. Wouldn't that put the nut nearer the cam though??

[roverman]

Nic and clan, pic is of a "stocker"? Look similar to my 907,"deisel" rods,900 grams must be, right? VW ,aftermarket, is quite thinner/rounded on bottom. Depends on where they bump. Buick V6 with "even fire" crank, reportedly they bump on top near bolt. "Fat Performance" or "Empi" might have pics'.rovermn.

[roverman]

Looks like our "threads", are getting  twisted? Jim's talkin why flat tappets in "rockers" and Nic's bespeakin rods in the "rollers". I'm about to get confused. One way to enhance street-use power is to improve "lift/flow under the curve", meaning heads with good low lift flow and open the valves faster. Faster in flat tappet Buick/Rover,sbc is limited by smallish .842" dia of lifter. OEM. didn't go to hyd. rollers because they "like" to spend $'s needlessly. Longevity, reduced emissions and better performance are some of the reasons. Limiting a Merlin,TA or Wilcat head to under .500" lift and 7k redline may prove counter productive compared to a skilled roller set-up. In my experience around OEM. 215's, the best thing a flat tappet cam did was go flat! Fortunately, our oils, "with zink", have improved since then. Long live Diversity University, roverman.

[pcmenten]

As Art says, it's 'area under the curve' that helps build torque. Since flow in the ports of stock heads seem to hit an inflection point in the .400/.450 lift range, improvements below those lifts will help with performance. Also, with the faster ramp rates possible (and better low-lift flow) with roller lifters, overlap can be reduced and LSA can be widened.

This helps with electronic fuel injection, and for those of us who live in areas where emissions are tested, this helps with emissions.

To recap and make sure I'm on the same page, it's Chevy 3.1L 60^ V6 roller lifters and dog-bones. What was the retainer/spider? Looks like it bolts down, so it might be a stock Buick v6 part. getting two and cutting/splicing them should work, right? And, obviously, all this stuff will work on 215's, 3.5, 3.9, 4.0, 4.2, 4.6, 300ci, 340ci, and probably 350ci.

[roverman]

Paul and all, Yes it must be Buick V6, as to what years? (2) V6 retainers/spiders, overlapping?-maybe. As to why example used chev 3.1L vs. Buick? In leiu of sheet metal conversion, I shall investigate alternatives, including if 3.1L is identicle to sbc hyd. roller. Anybody know if 350 Buick and late V6 use larger base circle on cam? Thanks, roverman.

[mgb260]

I have been following this thread and read all 9 pages on the V6 roller conversion. It uses the dog bones and retainer from 86-88 Buick V6 roller engine. The Chevy V8 lifters are too tall. The 3100-3400 (3.1 and 3.4) rollers are the perfect height and same diameter as the Buick and Chevy V8. The Turbo Buick V6 3.1 roller thread says it works with the stock base circle for Buick V6 (1.234) . Also move the spider mounting bolts a little to avoid the oil gallery. Here is a picture of that and a picture of a SBC with the 60 degree 3.1 lifters from a Corvette forum.

[BlownMGB-V8]

I guess twisted enthusiasts just can't help making twisted threads.... but isn't that what threads are? Twisted I mean?... anyway,
On my scat rods, which were capscrew type, the shoulders interfered with the cam lobes. The upper shoulder and one capscrew had to be trimmed to clear.



 On the bottom, they hit the pan and I will need a pan spacer or girdle plate there, about 1/4" thick. Someone on the Buick board has started working on a cad file but may not get it done by the time I need it.

From Kurt's old article on the D&D 300 based 340 stroker it looks like the same issues came up, along with the need to trim the piston skirts. With the BOPR based build I'd guess it'd be about the same, and the shorter rod might mean more of the shoulder would have to be trimmed.  The stock 350 rods used a capscrew type rod bolt which gave more clearance at the cam I believe.

Paul's comments make sense. Enough to justify the extra cost though? That's the part that is hard to say. For me, no. For others of you maybe so. But then, I'm not hampered by reliance on atmospheric pressure to do the cylinder filling so as usual I'm off on some tangent that only has a little relevance to the mainstream. Consider this though, if you plan to put a whole lot of miles on the engine,  when the time comes  to rebuild you will probably be able to reuse your roller gear with minimal servicing whereas the flat tappet cam, lifters and rockers will probably need replaced or rebushed. So that's another advantage worth considering.

Jim

[NixVegaGT]

That's a good point about longevity. I've spent a bit extra on lifters with little oil holes on the lobes because of the aggressive cam I'm using. The reality is it's not gonna last. That's $350 down the drain just for the cam.

So the cap screw rods you guys were talking about have the holes threaded. Huh. Make sense.

HEY! You brought up the VW rods first, Art. LOL!


Whatever happens you've got to admit this is fun, right??

[roverman]

Something we haven't discussed, aluminum as a lifter bore material vs. ci. We know ci. is superior as a wear surface, right. How many of us check "exact" clearance, lifter/bore? We know oil requirement will increase to "square" of clearance increase. I'm thinkin that alum. bore that has a flat tappet, rotating and sliding will likely wear faster than a roller? Nic, please don't fret that the roller set-up weighs 31.7 oz. more.roverman.

[roverman]

Hello pro-roller people. 48 lifters on-the way. Still no "rockers". Waiting on cam quote. rollin on a ...........roverman.

[pcmenten]

Awesome. Are those the Buick 3.1 roller lifters from 86-88? Did you order them new?

[roverman]

Paul and all, Yes, thanks to this forum and to those that keep it real. One of the next steps will be what "masters", Doug Herbert has. "Dog bones and retainers" also available for good prices. Paul, you have your desirable cam spec's. yet? roverman.