For the same reason that the factory increased the size of the crankcase on the BBC,to allow for bigger counterweights on the crank,which is always better,balancing isn't the only purpose of counterweights on a crankshaft,but I guess if you had known that you would have been able to create a logic to fit that situation.Why would you ever want to modify a block to fit a "pennies on the dollar" crankshaft? If I decide I need to fit a larger tire on a car, I don't get the torch out to make the wheel well bigger before I let a little air out of the tire and flex the axle first. Small/cheap parts that they made millions of should always be modified first. To modify the foundation of a home to fit around a flower is to forget one can simply dig up the flower to move it anywhere in the world.I can't create a logic that fits this situation.
What is the difference between 348/409 oil pans? Is there a difference between 340hp and 425hp oil pans?
- Thread starter 1964SuperStocker
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Well I have personally had 3 454 cranks machined to drop in a 348 and have had no issues what so ever getting them to balance. I would suspect that the person or machine doing the balancing needs to be changed. That is not a put down, I'm saying that as technology gets better so does the machine work. The tolerances get better and better all of the time and I'm simply amazed how far we have come machining parts in the last 15 years. Most processes are computer controlled now to so less chance for mistakes.
I hear what your saying,I'm doing exactly the same thing I chopped the counterweights on mine too to expedite the build.But if I find out that just the rear counterweight can be reduced and not be a problem,thats the way my future builds will be done.Clearancing a block for a stroker crank is very common,and as I said before counterweights are not just there for balancing,while they are drilled to get final balance that is not their only purpose.Out of curiostity the 3 cranks you had done did you have to use heavy metal (Mallory) to get them to balance?If not do you remember what piston and rod weight was?
Something like this would likely 'find' you 10-15 horse power over those nasty factory things or a 'click-clack' repro.
And get an Eagle crank to while your at it. We got our first Eagle crank in 2006. Up till then three 454 cranks and a lot of miles driven to and from crank grinder and begging to get it done “RIGHT” by next Christmas.Plus a lot of grinding by Ronnie. It always cost me a couple rounds of golf and many beers after he prepped a block for a 454 slug!
That's fun! How much does one of those cost? I'm just barely going to get 6000rpm so I'm wondering how much the average engine would really need such fancy work. Any input on when it becomes important RPM wise would be great.Something like this would likely 'find' you 10-15 horse power over those nasty factory things or a 'click-clack' repro.
It was much cheaper to get my 454's ground than buying a pre-made piece and budget was key to my 434ci build. Again, not a race piece either, not going to hit 6100rpm at any point.
Super stocker,do you know if you had use Mallory to get your cranks to balance?And if not do you have the piston and rod weights?I will soon be taking my rotating assembly to get it balanced,and want to avoid the use of Mallory if at all possible,if I have a target bobweight to stay under it will increase my chances of success.
How fast are you planning on spinning this rotating assembly when your car is at full power? There always seems to be a mix of opinion between the all out drag racers and the shade tree mechanics spinning less than 6000rpm. The 3 forged cranks I have had done so far have had no issues with removing material and some weld. No Mallory used. I did go with forged internals and externally balanced but never planned on spinning above 6000 with my personal build and the others were on 400hp builds that spin slower than mine. I have over a dozen 454 cranks and a hand full of 396-427 cranks currently. One piece of advice I would give is don't take your performance motor/parts to any shop that simply builds motors. There is a vast difference in knowledge and ability.
I have a number of cranks 348, 409, 396, 454. I don't know if I can find time to line them up and measure but maybe tomorrow night I can.
Yeah mines not going to be high rpm either,external balance,icon pistons,and BBC truck rods with arp bolts at least for this first motor,its just going to be a truck motor.What pistons and rods did you use?I get that about the machine shop,thats why I want to nail down the particulars to minimize the possibility of missed communication.
You won't have over $25 in it, if you do the welding. Some sheet metal, tin snips and some common sense eyeball engineering is all you need. Add a windage tray (meshed or louvered, not solid) and you'll be in good shape. Pals that run low RPM (<6,000) NHRA Stock Eliminator stuff (Pontiacs and Buicks) have seen dyno-backed 12-15 h.p. gains with just these modifications.
You are talking about the screen portion only right?Does it matter how far away it is from the rotating assembly for it to be effective?The closer things get to the spinning crank the nervouser I get.
You are doing the same thing I did 2 years ago. I'd have to look at my rods now. I can't remember which I put in. Either a truck thumb rod or something. I was thinking I over built the bottom end in case I wanted to add some NOS. I've done several motors since then, I'll have to double check. The crank is a 1970 454 forged piece and the pistons are the Forged ICON 10.8:1 @030 over to make 434. I'm running 690 heads that have had some work done to them and running 881 intake. Had an issue matching up screw in rocker studs to get them to fit the way I want but that is solved now.
I wondered because in my mind 6000 rpm isn't anything to laugh at but wondered whether I should have spent more on the crank because they asked me if I wanted to knife edge the weights before they were done. Decided not to but now I wish I would have. I did pick up a 454 crank that someone has knife edged and used Mallory to balance it. Might end up in my next build because its real pretty. I'll have to look into what it would take to add some of the screen in mine. Even 10hp is a big deal.
Take a look at what's holding the screen in place and how it's positioned. On the drivers side of the pan, the solid screen edge is bent to act as a scraper. On the pass side of the pan, the same thing applies. The screen is fastened to the pan with button head screws through the side of the pan. The front trap door has four 1" holes in it...the swinging 'door' uses a piece of welding rod as the hinge pin. On the back, the shelf keeps oil from coming up the back of the pan and getting around the rotating assy. You could substitute a main cap baffle that goes between the oil pump and the main cap:
Or, make up something along these lines:
Both will help power and decrease aeration, even on a street ride.
Knife edging is one of those things that looks sexy, but it's advantages (if any) are only there if the oil pan has been optimized first.
A good oilpan also serves to keep oil flowing on shutdown
I was kind of thinking the more effort spent on windage reduction = diminishing returns on knife edging.I thought the sump baffle looked a little like an LS-7/Corvette trapdoor baffle.While Ford ,Mopar,and Pontiac all used some sort of baffling or windage trays on their HP motors,I believe Chevrolet paid a lot more attention to it than the others,the only thing I've ever seen approach Chevrolets offerings has been the somewhat over the counter factory deep sump for the Ford FE with its baffling and unsophisticated crank scraper.Take a look at what's holding the screen in place and how it's positioned. On the drivers side of the pan, the solid screen edge is bent to act as a scraper. On the pass side of the pan, the same thing applies. The screen is fastened to the pan with button head screws through the side of the pan. The front trap door has four 1" holes in it...the swinging 'door' uses a piece of welding rod as the hinge pin. On the back, the shelf keeps oil from coming up the back of the pan and getting around the rotating assy. You could substitute a main cap baffle that goes between the oil pump and the main cap:
Or, make up something along these lines:
Both will help power and decrease aeration, even on a street ride.
Knife edging is one of those things that looks sexy, but it's advantages (if any) are only there if the oil pan has been optimized first.