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-   -   421 or 434? (https://www.racingjunk.com/forums/showthread.php?t=19883)

lookingaround 02-17-2008 11:26 AM

421 or 434?
 
im going to be ordering my crank tuesday. im using a stock 400 block. i want to build either a 421 or 434. is there less clearancing with the 421? i dont want to weaken the block anymore than i have to. do i have to run a small base cam with both? id really like to do the 434 but not sure if the block will last to long.ive got brodix track1 heads 228 intake runners 2.08 intake 1.60 exhaust valves. probably around a 630 to 660 lift roller cam. 750 aed carb 4500 stahl 350 turbo with brake. not sure what gear yet probably a 28 or 29 inch tall tire. what gear would you recomend? what kind of times do you think it will do? i run 1/8 mile.oh yeah thinking about some small dome pistons. 11.5 to 12.1 ? any help would really be appreciated. possibly some NOS to

hammertime 02-17-2008 11:43 AM

IMO your taking a chance going that big with a 400 block, I've seen people do it and have good luck but then others who broke several blocks before they decided to get a aftermarket.
I still love a 406 :lol: :D I had a 434 in one of my cars, small base circle is almost a must.

I972Nova 02-17-2008 02:47 PM

we had a 406 that ran a best of 9.76 and we built a 434 that was the same parts and it ran a best of 9.68... I think it ran 6.14 best in the eighth at 3200 pounds with a 4.86 gear 32" tire.

both motors were almost the exact same heads, cam, compression, intake, carb. We ran a 1050 dominator on gas.

The 434 we ended up half filling the block and it was a little harder to cool down between rounds than the 406.

If it were me I would build the 421. you have little to no clearancing to do and the best bang for your buck in a stock block.

I hope this helps.

lookingaround 02-18-2008 02:22 PM

thanks for the info guys

zipper06 02-18-2008 03:19 PM

I'd go with the 421" like other said very little clearancing on the blk, also if you run Eagle rods, they use 7/16" rod bolt heads which helps even more on the clearancing. We have a couple 434's with stock blks and so far no problems, in fact the stock block is quicker than the after market 434" by a tenth 4.80's VS 4.95 in 2 different dragsters, but it's filled to the water pump opening and we run a main girdle.
You will have to run a small base circle cam with either one 421" or 434" and some cam companies call .925 dia a small base circle, but in reality you'll need to be below .900 dia. My 434" Bullit cam is .875 in a dart little "M" blk.
4.86 sounds good with a turbo 3.50 trans, if it were a PG, i'd go 5.13 or 5.29 gears, for the 1/8 mile runs only.

JMO

Zip.

lookingaround 02-18-2008 04:34 PM

thanks alot zip.

altune 02-19-2008 04:22 PM

The new Compstar rods, have rod bolts that have to only be clearanced a little on stroker motor 434 cid.

lookingaround 02-22-2008 02:24 PM

got my crank today.
http://i83.photobucket.com/albums/j2...laze/crank.jpg
http://i83.photobucket.com/albums/j289/ProBlaze/c2.jpg

dciracing 02-22-2008 03:25 PM

did you find the made in china tag in the box.

lookingaround 02-22-2008 03:57 PM

no should i?

v8Fiero 02-22-2008 04:25 PM

very nice! then again Im a bit biased towards that crank :D

I cant wait to see how the rest of the build goes.

cncmotorsports 02-26-2008 07:29 PM

Buy the AED 950 carb, the 750 will be to small, also on the rods, eagle CRS6000BST2000 is what you need

lookingaround 02-27-2008 01:58 PM

those are small journal?
http://www.jegs.com/i/Eagle/356/CRS6000BST/10002/-1

us7race 02-28-2008 02:29 AM

Jegs site is listing them wrong...Check out eagle's site here..bottom of the page...


http://eaglerod.com/products/Chevy/s...BC%20rods.html

engineaction 03-01-2008 06:25 AM

I am new here, but read your post regarding the 421, 434 project. I would have your New eagle crank checked end to end with a Rockwell Scale for hardness. You will be surprised at the inconsistentsy. Also measure your rod and main journals, and order your bearings accordingly to accomodate clearances. If you use an Eagle rod and you have intentions of putting your engine on the spray, stay away from the lightweight series H-beam rods. The ARP 2000 rod bolt upgrade is a must. Also take them straight to the machine shop, break them down, re-torque, and have them checked for size. Eagle cranks and rods are great items, but they do require some attention.

Josh
Action Engineering
www.actionengineering.net

topsportsman1 03-01-2008 06:53 AM


Originally Posted by engineaction
I am new here, but read your post regarding the 421, 434 project. I would have your New eagle crank checked end to end with a Rockwell Scale for hardness. You will be surprised at the inconsistentsy. Also measure your rod and main journals, and order your bearings accordingly to accomodate clearances. If you use an Eagle rod and you have intentions of putting your engine on the spray, stay away from the lightweight series H-beam rods. The ARP 2000 rod bolt upgrade is a must. Also take them straight to the machine shop, break them down, re-torque, and have them checked for size. Eagle cranks and rods are great items, but they do require some attention.

Josh
Action Engineering
www.actionengineering.net


X2 I agree with Josh here,this should get interesting if we can get actual numbers.
But then again some machine shops don't even know any thing about Rockwell tests.

I could go on here about some of these off-shore items but I am stoping now,You pay for what you get,like Josh said,you need to have these things,resized or even remachined,never take it for granted out of the box is fine,most likely they are not,and do require attention.

lookingaround 03-01-2008 07:12 AM

thanks for the info Josh and Tom


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