[BlownBirdy]

Even if it was possible to run valves that big in a 305 head, even if it was aftermarket, I wouldn't want that, right? I mean, a head with over 200cc intake and 2.02 valves is going to be overkill on my 334. I am just trying to get a handle on the basics of engine breathing. I think I have cams down a little bit, but the breathing of heads and sizes kind of confuses me.

[badknuckles]

if your going to put the time and money in a stroker 305 might as well get good flowing heads

[mikeweyman]

well, the 305 heads dont flow the best , but you must remember the motor is only the size of a 302.It may not run with the big dogs,but you will certainly be the boss of the 302 dogs left on the step.lol mike

[87442lover]

Originally posted by BlownBirdy
Alright, I know that I am going to get chewed on this one, but maybe not.
I am building a stroked 305, .060 over with a 3.75 inch stroke for about 334 cubes. I have had the block tapped for four bolt mains with the outer two bolts digging into the block at a 22 degree angle. I think it will hold. I plan to use a World Castings Torquer 305 head because the 58cc chamber should boost compression. The engine was rebuilt to stock specs about 900 miles ago, and just isn't cuttin' it. It is going to be rebuilt again. On and off I am working on a 383 stroker with a blower, but for now I would like to see this 334 come alive because the blower is going to set me back a lot financially. My question regards connecting rods. I plan to use a Scat crank and rods, but I am confused on the size. From what I understand, the pistons I am getting will work fine with a 3.75 inch stroke and 5.565 inch rods, but I was wondering how the motor would react to 5.7 or 6.0 inch rods. I am planning to run over 10.1:1 compression, but I don't want to go crazy because this is a Street/slight strip car. If I use the longer rods will I have clearance problems or is it just a matter of too high compression. The only reason I ask is because the deck height is 9.025 inches, just like a 350, and that works fine with teh 3.75 crank and 6.0 rods. Is it a matter of combustion chamber size? What about other combos like a 3.48 inch stroke with a 6.0 inch rod? Maybe It would be best to go with the recommended 3.75 crank and 5.565 rods. Anything anybody can offer will really help.

You can not use bigger rods with any setup without changing the crank again. If you did you would send the piston straight up into the head, end of story.

[BlownBirdy]

Yea, that's kind of what I figured, but I wasn't sure. One of my posts on this thread says what I plan do do, but I am not sure if it will work out. I will repeat what I put there in case anyone missed it. Any of your input would be great. 305 bored .040 over to 3.776 bore with KB186 pistons. 3.750 stroke with a 5.7 inch rod. Clearly I would have to get this assembly balanced. I know that there will be some machining involved so that the rods don't hit the cam and the balancing pads don't hit either. The compression height on these pistons is 1.433 and they have a 10cc D-cup head type. With a 58cc head, I believe I can get 10.1:1 compression, perfect for what I am running. I plan to use the World Castings S/R Torquer heads because they have 170cc intake runners the 58cc chamber I want and 1.94/1.5 valves. Plus, they are meaty, so I can have them ported and polished if i so desire. It was also suggested that I use a comp cams extreme 256 or 262 cam because of their midrange power. I would probably use the Performer Air-Gap I have, and probably a carb around 600cfm in size. i also already have a 6AL ignition with a Flying Magnet Crank Trigger and MSD distributor, so I would probably just put that set up on this engine. I was also looking at Supercomp headers. Any ideas?

[Duntov]

Even this thread is a few months old I wanted to mention that a 334 we did for our company using a set of 5.565 rods,.030 305 forged pistons and of course 400 flexplate and dampner. It was done with a set of old TRW 305 pistons a 1529 (400) crank turned down, .020 off the deck .024 of the intake surface of the 882 heads with believe it or not 1.72 valves little port window matching and throttle body. Even with the small intake valves it's quicker than most 350s around and definitely out pulls 'um. OH, ands MTC1 cam... Vaccum is unreal and 18mpg in a short bed 90 chevy. Biggest advantage we noted was it pulls a heavily loaded 2 axle dump trailer up through the mountains and never ran warm, and stayed in overdrive. The small valves were by chouce. took a while to find the heads. Thinking of building another one with cast pistons for my daily driver.

[American Muscle]

Originally Posted by Duntov

Even this thread is a few months old I wanted to mention that a 334 we did for our company using a set of 5.565 rods,.030 305 forged pistons and of course 400 flexplate and dampner. It was done with a set of old TRW 305 pistons a 1529 (400) crank turned down, .020 off the deck .024 of the intake surface of the 882 heads with believe it or not 1.72 valves little port window matching and throttle body. Even with the small intake valves it's quicker than most 350s around and definitely out pulls 'um. OH, ands MTC1 cam... Vaccum is unreal and 18mpg in a short bed 90 chevy. Biggest advantage we noted was it pulls a heavily loaded 2 axle dump trailer up through the mountains and never ran warm, and stayed in overdrive. The small valves were by chouce. took a while to find the heads. Thinking of building another one with cast pistons for my daily driver.

Few months olds, try 6 years. Still cool thread though

[Duntov]

Thanks American Muscle... Got any idea where I can get info on how to adjust the crank balance on a stock 2442 crank? I lightened rods by 6grams before I was finished with the balance fixture, Kinda like shaving side burns trying to get them even. Also my pistons and rings are lighter, altogether about 10 grams per assembly. My crank was well balanced before. Not scared to drill the crank, but can't figure out how much to take out, and can't find an appropriate thread for the formula. Thanks in advance. Duntov

[ericnova72]

Originally Posted by Duntov

Thanks American Muscle... Got any idea where I can get info on how to adjust the crank balance on a stock 2442 crank? I lightened rods by 6grams before I was finished with the balance fixture, Kinda like shaving side burns trying to get them even. Also my pistons and rings are lighter, altogether about 10 grams per assembly. My crank was well balanced before. Not scared to drill the crank, but can't figure out how much to take out, and can't find an appropriate thread for the formula. Thanks in advance. Duntov

Don't even worry about the balance, even the most anal professionals admit no need for rebalancing unless you change weights by more than 25 grams lighter per cylinder assembly.

[Duntov]

Thanks Eric,
That makes me feel better but I would like to know more about crank balance. I think it would be a good thread to start because there is so little information shared about the details/specifics/science as it applies to v8s.

I've noticed over time that if you have pressed pistons, the balance guy often either presses them on after or offers to. So when we get a small block in that's been balanced, (half of them) and press the pistons off, I clean and weigh them out. They usually average within a gram and a half from light to heavy. We do our own rods/pistons to a tenth gram. Not because we need to be to a tenth for our RPM range, but partly because I don't completely trust our fixture and scale that much. So figures if we are within a tenth or two that they hopefully are inside of a gram. The crank though, we're at the mercy of someone's computer lathe and never really know for sure, what we've got.

You think enough people would be interested in the subject to create a new thread? Thanks Duntov

[BBCMudbogger]

I don't think you are gonna balance your crank with a lathe and drill bit.Google crankshaft balancing and see what you can learn.

[ericnova72]

There is no way you will be able to find anything that will tell you where to drill the crank at home just based off the amount you have changed the rotating and reciprocating weights as crank balancing is done on a dynamic balance machine, not static balance. With the small amount of your change just put it together, more than a few pro's "overbalance" the cranks they do, like 51-52% balance factor rather than 50/50, with the crank counterweights just a little heavier than the balance formula suggests.

[Duntov]

I've no doubt you're right Eric. You too BBC, my lathe and bit comment was reference to a dynamic balancing fixture. Our balance buys used to call them balance lathes or crank lathes back in the day of analog fixtures 60s and early 70s. That's what I meant by lathe and drill bit. We had one in the shop in 69 and it dated back to late 30s Germany, but formulas have evolved since then not to mention accuracy with the newer digital units. I'm going to start a balance thread to see if someone with share the formula. Thanks Duntov

[projeklowrider17]

i've got an 305 bored 60 over and it ran pretty good before the computer went out of wack