Technical Mallory metal in a 292 Chevy straight 6

Taking off on a different tangent than what I've been going at recently. I dropped my 292 Chevy straight 6 off at the machinist. After much conversing with Schneider cams and him we decided to go with a Schneider 130H grind cam and change the lobe angle to 108 degrees. Only other mods to be done to this motor at this time are a cast header, a set of Rhoads lifters, deckin the block and head enough theyre fkat, a .030" overbore (which is what it took to clean up), went .010" under on the crank and rods (again, clean up), and an offy intake with 2 Rochesters instead of 1. Should make 200hp no problem. We are also goig to balance and blueprint it. I dropped off a brand spanking new pioneer balancer and a flexplate today as he sends that work out. He tells me it will probably need about 6 grams of "Mallory Metal". I have no idea what that is. We have also drilled and tapped the crank for a balancer bolt that it never had with a sleeve guide he made sometime back in the 70s. What is Mallory Metal and what will all of this balancing and blueprinting do for me? Should add we are using a stock type cast piston, original rods (albeit reconditioned with ARP bolts), and at his suggestion ARP studs for the mains and head, and factory type pressed pins. Does this sound like a good recipe for a street motor to go in front of a 700R4 auto with an 1800ish stall converter, with a 3.78 geared Banjo behind it and a 28ish inch tall back tire? Rear tires are 6.00-15 bias plies and the car should weigh right around 2300lbs with me, the wife, and the kiddo in it and a full 7 gallons of fuel (see, there's a reason I'm building a 4 door)

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why Rhodes lifters?and why the cam centerline change? It looks like the normal grind of the cam should work well with the combo you are building.

Mallory Metal is mostly Tungsten, it's much more dense than cast iron, so it can be used to add weight to the counterweights on a crankshaft, to solve balance problems. I don't understand why it would be needed if you are using stock pistons and rods? the only time I've needed it was when putting heavier pistons in an engine.

 

Mallory metal is expensive and heavy , it’s used for balancing cranks when needed. whats the duration on that cam?
Beat me to it !

 

Screen shot of cam specs straight feom Schneider.

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Rhoades lifters are the same price as Schneider's and my machinist thinks it will make the engine live a little longer. Centerline change was at the suggestion of Schneider to make it idle a littke better since I'm so close to a stock motor and don't plan to rap this motor out a bunch.

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Rhoades lifters will make more noise; is that what you want? They are designed to bleed oil off at lower RPM's, and at higher RPM's, the pressure overcomes the bleed off; it's done so you can run a more radical cam, and get by easier on the street. Why the studded main and head "bolts"? You stud the mains, you have to line bore it also. Read up on balancing before deciding you really want it done. He thinks "it'll need about 6 grams of Mallory metal"; again, read up on balancing, and what's he basing this on? Blueprinting is making sure everything, clearance-wise and tolerance-wise, is as ideal as possible. Unless you plan on driving the wheels off the car, or seriously racing it, you don't need a precision balance, or blueprinting. Kinda sounds like the machinist wants to buy a few new toys you'll be helping to pay for. JMO
I am Butch/56sedandelivery..

 

In all my years of balancing engines I never had to add heavy metal to a inline 6

 

112 or 108 lobe centre? You said one but show the other , could make a small difference. Compression ratio? and stock or ported heads (stock size valves) intake? I’m wondering as there mabe something with a little more duration that will work, I’m no Chev 6 nut but also look at dual pattern cams.
Blueprinting is useless unless your racing in a 100% stock class. It would mean a stock cam as per manufacturers spec ( would include “ optional cam”), no extra stroke , no porting other than to max spec. . No changes to intake or carbs (other than “optional parts”) Only max overbore , nothing bigger etc. some people take it to mean carefully assembled but that’s how it should be assembled, blueprinting is to get the absolute most from a completely stock engine (as per manufactures blueprints or other approved drawings)

 

Sounds like a nice build I would skip the Rhodes lifters your cam isnt big enough to have to need them and I would be suprised if it needs malory metal added but you will not know until you spin it

 

I'd take that motor to another machinist....

 

Probably want to re-think the "stock" pistons ... maybe some 9 to 1 pop-ups for a little more squeeze.

 

108 degrees. We were talking to the guys at Schneider and they suggested the change in lobe angle to make it not so choppy on idle. But otherwise all thise specs are the same.

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I see several things that strike me as odd.
To expand on somethings already mentioned;
Inline engines are inherently balanced. No way can a machinist look at a crank and estimate the amount of additional weight that will be needed.
The cam will idle better at 112* lobe centers than 108, but you might get a bit of low/midrange torque. The Rhoads lifters will cover up some of the poor idle you will get by tightening up the lobe centers. I would look for a cam with more lift and not necessarily more duration. You should easily be able to have .500" with 1.75 rockers with no noticeable difference in idle.

To learn what works in that 292, you Leo Santuci's book.

To get the right combination for your engine talk to 12Bolt Tom.
https://www.12bolt.com/
And to learn a ton about camshafts get David Vizard's book on that subject.

 

We thought about it. But to make the Banjo live under the back I need to not get too crazy and according to my machinist I can make my power goals with a stock type piston. This motor was pretty high mileage when we got it opened up and at 1 time blew a head gasket and we had to to take quite a bit off the deck and the head to get everything flat.

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Just saw your post about the lobe centers. I'd like to know more about how Schneider came up with that.

 

Got some odd numbers with that cam 206 degress with .460lift? That is too short a time for that much lift, the ramp will be straight up and then down.

 

The guy I talked to at Schneider said the change in LSA was to lower the RPM we start to come in to torque and make it a little better on the street but still give me power up high. With the 3.78 gears in my banjo and the overdrive in my 700R4 I should be cruising right about 2750rpm. The more I think about that the more I don't like it (may have to see about getting my rear wheels widened a bit and maybe running a 7.50-16 rear tire, the height difference should my lower my cruising RPM down around 2380). In reference to the amount of mallory metal that's what my machinist says he's seen on other 292s he's had to go overbore on and grind the crank under.

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If it was me I'd leave that cam like it was to begin with and skip the Rhodes lifters. Looks like a stock convertor would work fine.
Pete

 

Guys at Schneider recommend 1800-2200rpm stall. So yeah, basically a stock converter.

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I run the early Rhoads lifters in my stock 250 engine, I like the way they sound. If you go with the newest Rhoads that are adjustable, you can have a better idle, more vacuum and a solid lifter once above a certain rpm. Dad switched his Pontiac from early to adjustable Rhoads and picked up almost 2 mph in the 1/4 and a couple tenths et. If you order them with the outside oil groove, your cam will have a bunch more oil dumped on the lobes.

 

We are also thinking more oil on the cam is a good thing...

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Because Mallory metal is so dense and heavy, a piece that only weighs 6 grams would be about 1/2" diameter and as thick as a razor blade. He obviously doesn't know how to balance an inline engine. I've lightened many Comp Eliminator 292 cranks as much as 12 pounds and have never had to install Mallory metal to balance them. Find another machine shop. What he is telling you is the equivalent of a guy at auto zone telling you that you need muffler bearings or bumper bearings. Just a tiny BB size blob from a mig welder would weigh more than 6 grams. He is trying to scam you.

 

Piston manufacturers take into account the stock weight of a particular engines piston when making oversize replacements. In theory, a .060 piston should essentially weigh the same as a standard bore piston; this is considering stock type pistons are being used. As far as the crank grinding, and metal "lost"; the weight goes back in with undersized bearings. Nothing is being lost, added, or removed, unless replacement parts weigh significantly more/less. This is't taking into account aftermarket pistons with large/larger domes. You basically have a stock rebuild engine, with a cam change that is't radical at all, and some added carburation/exhaust. I don't think your machinist is actually trying to scam you, as much as he's just wants to make it sound like he's a really knowledgeable guy. Six/eight cylinder, inline engines tend to have "slightly" more inherent vibration, due to their length and resultant "twisting", but you're not going to notice that; and balancing can't address that anyways. Balancing an inline engine is also done a little differently than more common V-8's; I tried to find the article I remember reading about it years ago, but drew a blank. That's the reason I said earlier, to read up on engine balancing. Keep us posted on your project and progress. I am Butch/56sedandelivery.

 

I don't think he is either, but the only time I've ever balanced a motor was when stroking it, and raising compression, and changing rods, and building race motors. Should it run a little smoother being balanced?

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ALL engines are FACTORY balanced; a PRECISION balance just takes it a step or two further. Are YOU going to notice it? NO. Would I have a daily driver type STREET engine precision balanced? NO. In the mid 70's, I built a 250 six; stock short block with a too radical, flat tappet, mechanical lifter, camshaft, Clifford intake a with a Holley 2 barrel, Clifford full length headers plumbed into a stock Nova dual exhaust, Mallory dual point distributor, a Judson coil, and a 194 head head milled .060. Like I said, a stock short block; just a FACTORY balance. Very impressive for 250 cubic inches! The car needed some decent gearing; it had 3.08's in the rear-end, but it had an early Borg Warner T-10; not one of the later, lower first gear, Super T-10's. I am Butch/56sedandelivery.

 

What kind of car are we talking that has 4 doors and only weighs 2300lbs fully loaded?

 

Exactly.

The idle with an LSA of 108º will be rougher than 112º. You might end up with less peak torque, but there should be more usable torque available in lower RPM's.

I have a cam with a 108º LSA in my Falcon 200 six. It is sedate at idle, because it has EFI and has a Idle Air Control valve (IAC) that manipulates the airflow to keep the idle smooth(er), but you did not hear anything about EFI from me, on this board.

I chose the LSA and had the cam ground that way, because I am running a 6-speed, with two overdrive gears, and want the RPM's as low as plausible at freeway speed, without lugging the engine.

I could care less about the torque at 5500 RPM. I need it good at 1800-2000 RPM.

 

A bare bones 27 t with an inline 6 and an aluminum automatic. Interior is next to nill, and creature comforts (radio, heat, AC, etc) don'y exist, neither does glass aside from a windshield.

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I agree. In a perfect world I would like to start makin torque about idle and peak right around 2500rpm.

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You need a new machinist. This one is giving you a lot of BS. Probably needs a new set of golf clubs.