Hi Fellas, I saw an old friend, He is redoing his '69 Camaro SS. I saw the motor on the engine stand and I asked what size is it? He told me it was a 434. I asked if the block was from Dart or a Motown block from World Products. He told me it was a stock 350 block that the machine shop done up for him. I was wondering if it it possible? And what a the specs on it, because I would start building one tomorrow. Thaks for the info, Guy.

 

nope, a stock 350 will not make an engine that large. you need to base it from a 400 block, which it could be if its a factory block. It will have 3 freeze plugs on the side if its a 400

FWIW, you can fit a 4" stroke in a stock 350 block, which makes a 408, which i have in my car. that takes work. but i see no way to make 434 from it.

 

You would start with a 400 Block. NOT a 350 block.
434 is a 400 overbored
4.00 inch stroke crank
6.00inch H beam rods.

the 509 casting, while only a 2 bolt, is the most highly sought after of the 400 factory blocks. The reason are the 511 had less material in it's thinner main webs. These were beefed up in the 509 block. Also the 509 was a high nickel block, I don't believe the 511 or 817 were. Not sure on the 817. Some 511 replacement blocks were actually only 2 bolt, although rare, they would still have the thinner webbing. Another member reported recently that his machinist showed him the 509 block was 10 pounds heavier than the 511, that's significant. Many say the ultimate 400 factory build is a 509 block with splayed caps. But I feel that splayed caps would be a waste of $$ on a factory block. First because they have stepped registers and second you don't need to go splayed until you are making enough power that you should already be looking at an after market block.

Bottom line though is going beyond .040 or .060 is a risk, hopefully you'll sonic check it first. Also the factory blocks have much thinner decks, which you'll need to cut get your quench right, so that makes it even thinner and these decks are known to crack. (along with cam core shift) They've also got thinner cylinder walls. Also not all 400 factory blocks have the same number of coolant holes, make sure you've got the large hole between the center two cylinders on the exhaust side of the deck.

A 434 will be able to be made to fit, but anything beyond 550 hp you should start looking at an aftermarket block in most people's opinion.

 

Thank you Guys, I thought he might have been blowing smoke, we are both old street racers back in the day, him being into drag racing and me into road racing. Fifteen years ago when it was time to built a final project for myself (as in the last car, but keep upgrading), 2 cars came across my path at the same time. A 1968 plain jane camaro and the 1983 Z-28 that I own. I picked the Z-28 because I liked the looks, driveablity, and over all set up. I also liked the 52/48 weight distrubution compare to the '68. Thats why I will always pick a 3rd Gen F-body over any other gen F-body and my is also registered a a classic so I do not have to run any smog crap on it.

A lot of friends tell me to go from the SBC to the LS motor. But do to my situation that is on the back burner. I do plan on going with something larger than a 427ci motor and I get most of my blocks from World Products. I think they have great products that I used in the past. Guy

 

you can make a 427 from a 350 block, although i wont disclose what casting number you have to use.....4 in stroke 4.125 bore..... aftermarket block is the way to go....i have 4 509 blocks, one with splayed caps.....and looking for an aftermarket now......and not all 400's have 3 freeze plugs, some only have 2 with a boss for a third, and some have 2 with no boss.....i have all of the above

 

you cant bore ANY factory 350 block to 4.125". so without any info on that i call BS

 

x2 unless your talking the GM bowtie blocks. Deff. not an off the sheft/outa a car block.
most we ever took em is .080 and those are throw away motors when done for a season.

 

weve done around 15 of them, sonic checked, for street stock class.....all 4.125........and 1 busted a cylinder wall.....it was over 13.1......and im talkin production blocks........but its whatever....i know what weve done

 

You using a tall fill on the water jackets?

 

short fill, theres one production 350 block that the cylinder walls are so thick they damn near touch......specific casting number and specific plant....and im not airing it out on a public forum.....guess you guys will also say a vortec head cant be made to flow 300 cfm as well?

 

infernal..... i have a 350 roller shortblock with vortecs to put in my 92 when i have the free time and spare change, ive been slowly buying parts to build a roller block 302 for it....you ran your car with the setup you have listed?

 

It did a 14.5 at 101.8mph the only clean run I got with it (the other two runs I had, had some carb issues resulting in the car stalling at WOT during the 2-3 shift). That was right after I dropped the engine, T56, and really tall 3.27 geared (T56 first gear is a tall 2.66, much closer to a 700r4 with a 2.73 than anything else) posi rear in, carb straight out the box from Holley, and a 1.5 inch air filter on a drop base that choked off my primaries on my Hollley AND I was still learning how to drive a manual on the street, much less at the track. Did like a 2.8 60 ft or something awful like that. That was just a preliminary track day, first of what I thought would be many but life ended up getting in the way and I rarely had any free friday/saturday nights to go back.

Not proud of the time, but I'm proud of the out of the box trap speed I got. 3550 lb raceweight with me in it trapping at 102 = 295-305 rwhp.

It's tuned much better now, probably squeeze a little more hp out of it and hopefully at least a second, especially now that I've got a lot more driving experience with teh stick.

From what I'm seeing a crappy LT4 hotcam can still put 330-340rwhp down with just 1.5 ratio rockers. A Comp XR276 makes around 370rwhp. Not sure you can get much more than that out of it and keep it a practical street car.

I dont see why you're bothering to build a 302 though. You're just leaving power on the table that way.

 

I closed this post to give myself time to clean it up.

If you children are willing to play nice and by the rules, I'll leave it open.

 

"automatic response" hold up kid....i think im in timeout.....i cant comment while im in timeout, ill get a spanky

 

Sorry about the lauguage Kid, will not happen again.

I just ran some specs and all I came up with is 414ci with .60 over and 418ci with .80 over, both with a 4 inch stroke. But, I came up with 427ci with .60 over and 431ci with .80 over, both with a 4.125 inch crank. My question is, is it possible to run a 4.125 inch crank in a 350 block? I have built a number of 383 and 396 motors and is currently running a 396ci motor in my Z-28, so stroking motors is nothing new to me.

 

I dont see the advantage in drastically weakening the block to gain cubes via stroke or excessive overbore. I dont think a 4.125" stroke will clear but then again i never tried it. I just dont know anyone doing that nor have I seen it done anywhere on the net and I've been on alot of forums. take it with a grain of salt.

With the long stroke you limit your rpm ability as piston speeds get ridiculous and that puts alot of stress on the rod bolts. Piston compression height gets tiny so it hurts ring seal capability. Rod/stroke ratios also go down the tubes.

I'd think you'd be better off with a normal stroke length with optimal rod/stroke ratios, and just spin the motor higher to get more hp if needed.

 

I just would like to know if I can build a street motor out of of one, my 396ci puts out 472hp and 496ft/lb of torque, I did have it dynoed after I broke it in on the engine stand (the ones you can run motors on, I saw them run for about $500, I welded mine together for less and $100, not including battery and swap meet radiator, gauges and ignition switch). At 2000 rpms, it is already putting out 403hp. I will go into further details into the motor if you guys want me to.

 

think about it guy....a 400 with 3.75 stroke and a .030 over bore is a 406, a 400 block with a 4.0 stroke, .030 over bore makes a 434......and a 4.125 will not fit the 350 or 400 block...you hit water.......to get the rod bolts to clear....it might be possible with a honda rod journal....but with that stroke....the small rod journal will drastical reduce crank strength, and no matter the combination.....if your makin over 550-600......and not using an aftermarket block...its only a matter of if and when......unless you do all your own machine work and are using stock parts and head castings to make that......youll be hatin it when a stock block lets go of good internals

 

trying to take a stock 350 block to anything beyond .060 and stuff a 4inch stroke I wouldnt expect it to be a Street Motor and last long. As said above your running really thin walls. Your gonna want to run a block fill. Just not worth it IMO.

for the $$ your going to spend Just built a nice well built 383 or Start with a 509 casting 400 block and do a 406. Spend the $ on a Dart Block and have fun. Find a GM Bowtie block and have fun. but to drop all the $ in machine work , inch crank, pistons etc. and Cross your fingers you dont crack a block and grenade everything inside just isnt worth it.

 

Yeah, I see all of your points. I just stick with my 396ci motor. Thanks all, Guy