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#21
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I have never bought a balanced total assy package.
My builds have been a mix of aftermarket and stock parts or a basket of single sourced aftermarket parts all of which need balancing by my efforts I will say if I was to buy a single sourced balanced rotating assy I would expect to get a package that meets or exceeds OEM specs Precise or to your numbers spec attention to details would take more effort time and money for a higher end build
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If your not at the table you're on the menu A man who falls for everything stands for nothing. |
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#22
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I can tell you why I bought a balanced assembly - convenience and trust. I didn't have a good sense of my local shops at the time, felt what I would get from Butler would be good of the box to use and since they have a long history with Pontiacs I felt the risk was low.
My expectation in purchasing the assembly was that it was balanced with an industry standard spec (admittedly, I don't know what's acceptable) and would be equivalent to what any good local shop would do. When I showed the paperwork to the machinist that did my block he said the work was fine, but he said he would have taken it further in terms of balancing. One thing that did have me curious with the Butler kit is that there weren't matched rods, pins and pistons. That tells me that they're doing what Paul said - weighing each part and balancing the crank rather than matching the parts and spinning up the crank to balance. In hindsight, I should have weighed each part and matched them to get things as equal as I could to see if further balancing was required, but I didn't know any better. Anyway, that's my two cents from a hobbyist first time engine builder with just enough knowledge to be dangerous.
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Ken '68 GTO - 464 - Ram Air II heads - 236/242 roller - 9.5” TSP converter - Moser 3.55 Truetrac (build thread | walk around) '95 Comp T/A #6 M6 - bone stock (pics) |
#23
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Paul for me if I buy a "balanced assembly" I expect it to have matched weight piston/pins, matched rods and the crank balanced to what my local shop would do to performance industry standards. So I could drop it right in. If not why pay the extra for a balanced assembly vs the separate parts and not just get a good shop to do it correctly? They will have to start from scratch otherwise.
Of course to get really picky what weight for rings were used, bearings to get bob weights?
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Skip Fix 1978 Trans Am original owner 10.99 @ 124 pump gas 455 E heads, NO Bird ever! 1981 Black SE Trans Am stockish 6X 400ci, turbo 301 on a stand 1965 GTO 4 barrel 3 speed project 2004 GTO Pulse Red stock motor computer tune 13.43@103.4 1964 Impala SS 409/470ci 600 HP stroker project 1979 Camaro IAII Edelbrock head 500" 695 HP 10.33@132 3595lbs |
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#24
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IMO everything should be at least set on a scale. I had a guy bring me a used set of Carrillo rods for a Pontiac blower motor. One rod had been replaced at some point and was about 60 grams heavier than the other seven.... What a PIA that turned out to be. Last edited by PAUL K; 10-13-2023 at 10:20 PM. |
#25
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This is an acceptable connecting rod measurement tool set-up.
Tom V Most of the reset of the stuff out there is Bathroom Scale level attempts 1) Precision (accurate) Gram Scale. 2) Proper fixture to measure the Rods. 3) Proper scale to measure all of the individual parts.
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"Engineers do stuff for reasons" Tom Vaught Despite small distractions, there are those who will go Forward, Learning, Sharing Knowledge, Doing what they can to help others move forward. |
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#26
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This is how we try to explain a couple of terms being used in this thread. Our interpretation of these terms and practice works for us and may not be the same as yours or other race shops. Blueprinted engine: This is an engine build in which all important dimensions are checked either against the factory specs. (not tolerance). Or the engine owners "blueprint", based on the use of the engine. (meeting their specs.). Of course when working with machinery, hitting that exact spec. is difficult. So within the class, the tolerance we use is the spec. +- .0001. Most factory tolerances on old domestic V8's are +-.0005". Of course it depends what part we are talking about but in my example, this would be true for crankshaft measurements, oil clearance, housing bores. End play, ring gap, deck height and such, factory tolerance is greater.
As far as engine balance, that gets much more complicated. Crankshaft balance is often thought of as a "black art". Everyone agrees that a perfectly balanced rotating assembly will be very smooth and the bearings will last longer. The intended RPM, true weight of the components, the balance of the parts hanging on each end, internal vs external and imbalance on each end of the crank all have an effect on vibration. Type of transmission, engine mounts and other external components also effect vibration. I try to explain the situation relating it to a tire, something we are all familiar with. A crankshaft balancer is very much like a computer tire balancer. Same technology, greater sensitivity. An out of balance tire causes a vibration that can be annoying. If severe, it can wear suspension components at a faster rate than normal. Springs, shocks, joints can all wear faster. A computer tire balancer splits the wheel/tire assembly in half and you add weight to the inside and outside to reach a zero balance. (Typical tolerance is +-.25 oz. ) With a V8 crankshaft, you are trying to balance 100% of the rotating weight of the assembly and 50% of the reciprocating weight. This is because 1/2 of the reciprocating weight balances itself out naturally from opposing forces. Much like a tire, the crankshaft balancer splits the readings into left and right readings. Some of the imbalance cancels itself out if the right and left is on opposite sides. This plays into the counterweight placement on the shaft. The software and age of the machine determines the dead accuracy you can get. Our 30 year old basic Sunnen balancer will balance to +-3 grams on a mid-weight, (Pontiac) crankshaft. It looks like the Hines machine shown in this thread will balance to closer than 1 gram per end. That is fantastic. Factory balance on cranks we have spun, not necessarily Pontiac fall into the total imbalance range of 20-40 grams total. Very few are better than 20 grams. That's where I said it's unlikely you will feel an imbalance less than 20 grams on a typical passenger car. Sorry for the long post. Not intending to insult anyone's intelligence. |
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#27
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When I have had engines balanced the work often varies in price because some engines took more work to balance, more lightening on the rotating assembly, more expensive Mallory metal added to balance it. I balance the assemblies to save money and time to get it done quicker at the shop.
I looked it up out of curiosity, and Butler’s charge $200 to balance a rotating assembly. Which isn’t high, and not really low. When I see a “fixed” cheaper price in a rotating assembly with balancing, I automatically assume: 1. They assumed the rods came in a matched batch, and are close, but not exact. 2. The crank was balanced to the lightest Bob weight, measured from the lightest rod and piston assembly. 3. Nothing was done on ANY of the rod or pistons to get the weights to match. If something was done, it was very minimal. 4. Depending engine platform it is, the total crank out of balance should be close to a factory balance job. Kind of sounds to me like it will be with in that 20 to 40 range the Mike just mentioned in the last post. One of my friends favorite movie quotes when something seems cheap is from the 1980 movie USED CARS. When taxi’s are painted blue with water base paint to be sold as used cars….water base paint? “Sure, we don’t get much rain around here, what do you expect for $200, metal flake? Lol Last edited by Jay S; 10-14-2023 at 10:45 AM. |
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#28
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I have personally checked all of my engine internal parts on a very accurate gram scale
when I worked at Ford. I will probably only build 3 more engines in my lifetime. 9.5" "Short Deck" engine, 10.230" aluminum Butler engine, and a 11.0 cast iron "Tall Deck" engine from All Pontiac. Moldex always did the Balance Jobs (after I did the initial weighing of the parts). (They weighed them too and did the crank balancing as well as the Nitriding.) Last count they have done 32 cranks for me over the years. (Ford stuff, Hot Rod stuff for friends, and my own stuff. I always had a good relationship with "Whitey" and Mr Gillian. Same deal with Joe (Whiteys son). If you find a good crank shop treat them VERY NICE. And BE PATIENT. Tom V.
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"Engineers do stuff for reasons" Tom Vaught Despite small distractions, there are those who will go Forward, Learning, Sharing Knowledge, Doing what they can to help others move forward. |
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#29
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If the block was balanced previously, and then disassembled for inspection, then put back together again does it need to be re-balanced?
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Esquire '74 T/A 455 Y-code SD clone previously on Dawson's Creek: '74 T/A 400 '81 AMC SX/4 '69 FB 350 |
#30
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No Sir
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#31
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#32
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Moldex sure makes a beautiful billet crankshaft. Strong piece with exact dimensions. But as Tom mentioned, PATIENCE with a capital P. Like at least a YEAR lead time for a billet crankshaft, probably longer. So plan ahead. Not sure how long to have a crank ground and balanced. But don't expect 1-2 week service.
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#33
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Will Rivera '69 Firebird 400/461, 290+ E D-Ports, HR 230/236, 4l80E, 8.5 Rear, 3.55 gears ‘66 Lemans, 455, KRE D-Ports, TH350, 12 bolt 3.90 gears '69 LeMans Vert, 350, #47 heads: work in progress |
#34
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I've bought a balanced rotating assembly from Butler for a customer and it came with a bobweight sheet with all the weights. I'll try to post a pic of it.
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1967 Firechicken, 499", Edl heads, 262/266@0.050" duration and 0.627"/0.643 lift SR cam, 3.90 gear, 28" tire, 3550#. 10.01@134.3 mph with a 1.45 60'. Still WAY under the rollbar rule. |
#35
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From their website on the subject:
The Butler Process All rotating assemblies sold by Butler Performance, regardless of brand, are balanced in our shop by our experienced machinists. Most other shops offer assemblies unbalanced or charge additional balancing fees. We don't take anyone else's word when it comes to the parts we stand behind. We put all rotating assemblies through the Butler Process for quality and performance. Our internal balancing process ensures each part of the kit is put through a multi-step inspection process. We then weigh and pin fit the rods and pistons as needed. We computer balance the crankshaft to the rest of the assembly. This process ensures that all the parts of the assembly are matched to form a "Butler Performance" worthy assembly. We then document all weights and information on a balance card that ships with the assembly.
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69 Gto, 390 posi gears,th400 w/jim hand converter/406 pontiac/#64 HEADS/ 10:1 compression/ 190 PSI with/ TRW 160 thou domes / hooker headers 1 7/8, PRW 1.5 rockers, 405 Crower Springs, Holley 750 vac with proform upgrade, Performer RPM on points / 284 H Single Pattern Crane |
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#36
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#37
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I haven't seen much Butler stuff recently.
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#38
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Based on Kyle’s post seems it is a thorough balance job. Would be nice to see a third party review.
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Will Rivera '69 Firebird 400/461, 290+ E D-Ports, HR 230/236, 4l80E, 8.5 Rear, 3.55 gears ‘66 Lemans, 455, KRE D-Ports, TH350, 12 bolt 3.90 gears '69 LeMans Vert, 350, #47 heads: work in progress |
#39
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FWIW, I did not get a balance card with my Butler kit in late 2022. I was expecting to get a sheet with the weights and matched pairs of pistons, rods, ring packs as well as the location to install them. The rods had clearly been opened and inspected but they weren't labeled or numbered in the box. I'm not sure the pistons were opened and inspected, but they did come with a sheet from Ross that had the weight of each piston. The crank had been worked on as well and had my name written on it (rod bearing clearances were spot on).
I suppose the parts could have been individually balanced close enough to each other to where it didn't matter where they go (seems unlikely given what I've learned about balancing since), but I would have at least liked to have seen the proof. In hindsight, I should have given them a call, but it seems to be running fine.
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Ken '68 GTO - 464 - Ram Air II heads - 236/242 roller - 9.5” TSP converter - Moser 3.55 Truetrac (build thread | walk around) '95 Comp T/A #6 M6 - bone stock (pics) |
#40
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1972 GTO 468 2 Bolt Main w/Eagle rotating assy SD Ported 295 KRE D Ports 10.8 CR OF Hydraulic roller w/ 1.65 stainless rockers Performer RPM Intake Holley 3310 780 Vacuum Secondary TH400 with 10" Continental Convertor 8.2 BOP 4 pinion 10 Bolt with 3.36 gears 11.428/118.95/1.618 |
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