Chevy Nova Forum banner

1 - 10 of 10 Posts

·
Registered
Joined
·
32 Posts
Discussion Starter #1
hi
I got a 400 block that has a fresh .30 over bore. its a 509 block. 2 bolt main. it came with a 10/10 fresh stock crank and a set of 30 over weisco 12.5 to 1 pistons (used 5 races) but in nice shape. im not a big fan of stock cranks or 400 blocks. production blocks I mean. my question is being the block is already finish honed for the pistons, can I short fill it. I always did that first. second if I short fill it now can I tall fill iy down the road for a drag only app? also if I use the stock crank, im guessing I shouldn't spray it. I have a dart shp block and 200cc dart shp heads and a 4in forged crank im going to use to build a 427 out of. the heads are too small for the 427. I think they would work on the 406. I also have a 010 350 4 bolt block at the shop getting bored and clearance for a 383, should I use the heads (200cc shp) on the 406 or the 383. 72 nova street strip deal. thanks bhog
 

·
Registered
Joined
·
125 Posts
I had a machinist tell me you could do a short fill on a block that had been prepped already, you just have to check & make sure the cylinders don't push out & stay true. I would run those heads on the 383.

Sent from AutoGuide.com Free App
 

·
Registered
Joined
·
8,013 Posts
hi
I got a 400 block that has a fresh .30 over bore. its a 509 block. 2 bolt main. it came with a 10/10 fresh stock crank and a set of 30 over weisco 12.5 to 1 pistons (used 5 races) but in nice shape. im not a big fan of stock cranks or 400 blocks. production blocks I mean. my question is being the block is already finish honed for the pistons, can I short fill it. I always did that first. second if I short fill it now can I tall fill iy down the road for a drag only app? also if I use the stock crank, im guessing I shouldn't spray it. I have a dart shp block and 200cc dart shp heads and a 4in forged crank im going to use to build a 427 out of. the heads are too small for the 427. I think they would work on the 406. I also have a 010 350 4 bolt block at the shop getting bored and clearance for a 383, should I use the heads (200cc shp) on the 406 or the 383. 72 nova street strip deal. thanks bhog
I would not fill the block at all. Personally, I don't feel that it is necessary in a 400 block and certainly not in a 509. In case you don't know (but I'm sure you do) a 400 block has Siamesed cylinders making it strong in itself. The other reason I would not recommend filling the block is that you will be creating overheating issues, especially if you're running it on the street.

I also wouldn't put a ton of power on a 10 under crank. If the crank was virgin it can hold a lot, I know guys that run nitrous and totally believe in virgin stock 400 cranks.
 

·
Registered
Joined
·
32 Posts
Discussion Starter #4 (Edited)
I had 3 400 blocks fail over the years. (2 of them cracked the cyl walls) one 30 over and one std bore. one I broke every web out from number 1 to the rear main, I was just towing a dirt car. that's why I like to short fill the blocks. I ran remote oil coolers. I think the crank should be good to around 475 hp, with no nos. what do you guys think ? would I be ok with a 3500 stahl converter at she strip or would that be to much for a stock crank? with a stock crank I wouldn't spin it past 6250 rpm. still think the heads would be to small at that rpm? I am new to the strip racing. bhog thanks
 

·
Registered
Joined
·
1,040 Posts
I would not fill the block at all. Personally, I don't feel that it is necessary in a 400 block and certainly not in a 509. In case you don't know (but I'm sure you do) a 400 block has Siamesed cylinders making it strong in itself. The other reason I would not recommend filling the block is that you will be creating overheating issues, especially if you're running it on the street.

I also wouldn't put a ton of power on a 10 under crank. If the crank was virgin it can hold a lot, I know guys that run nitrous and totally believe in virgin stock 400 cranks.
:rolleyes:............. YAH , that 10 under takes all the strength away !!:no:...Now if it was a nitrided steel crank , and the heat treatment was ground away ,then sure i would fall for it !
 

·
Registered
Joined
·
20,088 Posts
I would not fill the block at all. Personally, I don't feel that it is necessary in a 400 block and certainly not in a 509. In case you don't know (but I'm sure you do) a 400 block has Siamesed cylinders making it strong in itself. The other reason I would not recommend filling the block is that you will be creating overheating issues, especially if you're running it on the street.
Fill the block for the track only or when running alcohol, but street-strip I am with you.

Buddy ran 250 shot on his running 9's for a 2-3 years.
 

·
Registered
Joined
·
20 Posts
Been running 406's for ever I would not fill either. Install head studs it is worth the investment they end blowing head gaskets when you are running high compression.
 

·
Premium Member
Joined
·
11,208 Posts
My experience has been that generally speaking when you hit 650 to 700 HP on a factory block and crank you are on thin ice. These parts are now approaching 50 yrs old, the blocks are prone to cracking cyl walls and cracking from the bolt holes to the bore under any power level today and the main webbing gives up at 650 to 700 HP generally speaking. For every story about a guy making big power with no issues there are 10 about the poor dude who had a massive failure. That's my experience with these antique factory GM parts.
 

·
Registered
Joined
·
32 Posts
Discussion Starter #9
talked to my machinest last night on phone. he said no problem filling block after finished honed,he said hes done it about 5 or 6 times before. never one he had to run the hone through it again on two cyls. it was not his machine work and he thinks it was just sloppy work to begin with. but he always checks to be sure. as far as the crank goes I was wrong it was only polished not cut. he said he still wouldn't use it for what I want to do. he said at least buy a 4140 or 5140 forged, or a used forged crank and cut it. he said one of his semi late guys has a scat forged crank in his car for 2 full seasons that's 30 under on mains and 20 under on rods. 8000 rpm 20 laps at a time. but he said cast just plain sucks. he said the 200cc heads would work fine to make 500 hp. he said they were making 500 hp with the old double humps for 30 years. any way that's what he said. I just don't know if I want to spend the money on splaying the caps. I do agree with the head studs . I always use arp studs. (mains and heads) even on 4 bolts. tks bhog
 

·
Registered
Joined
·
4,612 Posts
i would fill the block with torque plates on it , or a old set of heads with a head gasket ,,,, make sure its honed with torque plates ,, or you will be throwing away alot of power/ ring seal , or it might crack across the deck when the heads are torqued once its bored ,,,

my friends shop does a short fill on 400 blocks for round trackers and has no problems with heating

if the block is decked ,, I would go in and put a chamfer on the steam holes with a small grinder , or tap them and plug them with a set screw , then put a chamfer on the holes ,, a sharp edge likes to crack ,,
 
1 - 10 of 10 Posts
Top