The Molnar 3.25" crank is 80 lbs as it comes out of the box. I don't think there are any 90 lbs cranks out there.. Heaviest one I ever worked with was a 3.25" main Moldex, at 84 lbs. Resize and convert the mains to the 3" 460 Ford and the Molnar weight drops to 78 lbs. When I worked with Tom Molnar on creating that crank, it was designed for up to a 2200g bobb.. so if your considerably lighter than that, feel free to take some counterweight off it. I wanted something that would work for everyone, from mild stockers to wild race motors.. that crank gives you the option and the material to customize for your application. With a no-nonsense internal balance. I have an unlighted crower 3 " main crank, that is now .010/.020 undersize, and it comes in at 70lbs For reference, the stock 455 crank is 68 lbs and just for fun I put a 482 crank in the scale, it's 66 lbs.. That's a stock crank that has the rods offset ground to 2.100 From the heaviest to the lightest here we are talking about 14 lbs, of tight on-center rotating mass.. I doubt that in the average 3000-3200 lbs back halved GS racecar, you would see much if any difference on the timeslip. A tenth or two at the most. In an iron block, the more rigid the better, so I prefer the heavier stuff. It's all physics here guys, the farther the weight is away from the crank centerline, the more force it transmits to the block, and in the case of a rod/piston combo, that has to stop and go the other direction at blinding speeds, that area is really where we want to focus our attention. Light piston rod/combos will in fact make a difference, in how fast the engine will accelerate, which will transfer to the timeslip. Decades ago I ran a stock rod/Jahns piston 430 combo,.. the pistons were fly weight, at just over 500 grams if i recall correctly.. and that sucker would rev like nobodies business. That's why that motor, with the exact same cam and top end, was only .2 off the 464 that replaced it. JW
The crank is the spine of the engine, stiffness is the most important aspect in my opinion. Longevity would be next.
Yes,exactly,the 14lb crank won’t show much improvement by itself,but couple that with light pistons and rods,and now you are getting somewhere and even less stress on the block. Wrap it up quicker.
You act like it’s past tense. I still own weird Oldsmobiles too. A little more of a challenge to make power with those.
My reasonings for asking about another reliable source for our Cranks from a supplier such as scat was about delivery time and cost,Not trying to be the lightest crank out there.I know a long time ago scat didn’t have a good reputation, I think they have improved quite a bit over the years.The rocket Oldsmobile website has billet 4340 Cranks available four 1895. I don't know their supplier,Not sacrificing quality of course.
Their 4340 crank for Olds is decent,but you get what you pay for. I consider it a street/strip crank. Us serious guys that like to do things once are still having Velasco and Bryant make cranks for us. The biggest improvement for the Olds is there is now a block available to handle 800+HP without chucking the rotating assembly on the ground.
Tom I will ask my guys that work on everything, what the current thinking about Scat is.. Cheap junk last I heard, but they don't make anything for us, so I never have paid attention to them.. But if your looking for an $800 Forged crank for a Buick... not gonna happen, unless someone ponies up the big dollars... We have investigated that, it was my first discussion with Tom Molnar on Buick cranks.. the issue is the foundries have no interest in small quanity stuff, Sure they will forge a Buick crank for you, as long as you want to buy a lot of them.. I recall the minimum investment being in the 50K range... not realistic for the BBB, at this time, there are still too many good stock cranks around. At that point he mentioned a billet for around $2500 retail, which was just over half the price of what was available at that time for the 3.25" main Buick crank. Which was the only option for the stock block..TA's Crower 3" crank won't go 3.25.. So that is what we made.. it's an excellent piece, and a Great value for the price, The first run is sold out, 1/4 of them went to me... for customer's builds, and I converted all but one of them to the 3" Ford Main.. for a couple hundred bucks grinding time.. For the next run, I am working with Tom to do a 3" crank, in addition to the 3.25", so there will be a billet version of both. There is going to be a larger market for the 3" crank here, once the new iron block is released. JW
Thanks for the response guys, doesn’t hurt to ask. As far as finding stock Cranks where I’m at it’s almost impossible. So that’s kind of what I was referring to a replacement crank that is a upgrade from Our stock crank, but under that $2000 cost. When an iron block does come out that’ll be a game changer
