400 sbc steam holes cracked

Learn how to identify and repair your cracked engine block quickly and. The 400 ci block is the only chevrolet smallblock that has the steam holes on the deck surface. Dart shp special high performance small block chevy cast iron. These heads had multiple cracks around the center bolt holes. Doing some inspection and found out it was a 400 sbc. Below is a picture of the finished chevy 350 heads with the 6 sbc 400 steam holes drilled and a 3 angle valve job.

Anyone here ever have a problem because of small cracks like these. Felpro 1144 sb chevy 400 head gasket, multilayer steel, 4. Thermal cycling of cast iron causes them, not necessarily overheating. I had an old for truck with a 400 motor in it that froze so badly that i had. I remember a chevy 79 k30 back in the 80s that got a set of 350 heads bolted on a 400 block, without drilling steam holes. The guy wants to use this in a stout street engine. If you use 350 heads on a 400 you have to drill the steam holes in the heads.

Heads without steam holes can be drilled for them by using the correct 400 head gasket with steam holes as a template. Pat im assuming your 400 has stock heads then, do you know what casting number they are. The sbc 400 block was designed with steam holes in the deck and heads. Read the tech article on small block 400 cooling tricks, brought to you by the experts at chevy high performance magazine. Ill run it through my sim a little later for you and see what i get with each combo, assuming the same low flow dual plane and 600cfm carb. Stock 400 s usually come with 882 casting heads, which flow pretty decent for street use with their 1.

If you have done any of these things it will over heat if you did not match up the steam holes in between each cylinder. I have a sbc 400 that has a small crack in the cylinder head combustion chamber. Cracks at steam holes in 400 sbc don terrills speedtalk. I actually do this to about all of the 400s cracked or not. Maybe a month later it was back in the shop with cracked block if i remember right. Next insert 2 dowel pins into the heads dowel pin holes and lay the 400 head gasket onto the head over the dowel pins. I would drill the steam holes in the heads, but plenty of others have run a 400 without the steam holes and had no problems. Drilling new edelbrock heads for the vent holes needed on a 400 ci small block chevrolet. Someone may know more about this but my machinist never wanted to drill the steam holes, he stated that the only reason the steam holes are needed is if you intend to idle for long periods of time, creating heat in that area without a lot of water flow, whereas during normal driving as well. Jun 02, 2006 the average price of a guaranteed 400 sbc core block now that will machine to. I had a 36 willys pu with a stock block, crank, pistons, and heads 72 400 sbc isky z30 solid lifter cam and edelbrock torker, holly 700cfm too big and 4.

The last main differences are the 400 has steam holes in between the cylinders because they are closer together and and cannot use regular 350 heads without modifications. I just used a head gasket as a template and started drilling. When using aluminum heads, we recommend gaskets with soft copper wire rings such as 3441010. Details about performance 327350400 chevy cylinder heads 601 sbc new guides. Felpro also restricted water flow through the lower holes between the. If u blow a gasket and heads are warped, the heads will be cracked almost for sure. With proper machining, most overlooked powerplants can make good reliable power.

A machinist told me that todays gaskets are better and more forgiving and dont need the steam hole. Gm designed the heads and head gaskets with matching holes so anytime we use to have to replace a cracked 400 head we would take a 350 head or some of the racers would use a higher compression head and use the head gasket as a template to drill the steam holes. The chevrolet smallblock is byfar one of the most versatile v8 known to man. I have found another one that has been rebuilt in the last 4 years and the reciepts are there and the crank is still good but it was bored over. Fulltorque being installed to fix cracked bolt hole. The average price of a guaranteed 400 sbc core block now that will machine to. The first step in figuring out how to fix a cracked engine block is identifying where the. The general thought with the 400ci sbc is, when they are overbored by more than. You can not mix the 400 crank with a 350 damper or flexplate. With the outside thread geometry we can fix cracked holes even into a water jacket. Steam holes, the cooling mod for 400based smallblocks. If you put the wrong head gaskets on it they are probably blocking the holes. Small block 400 cooling tricks tech article chevy high. If that 882 head is not cracked now, there is a very good possibility that it will.

If you intend to put any revs on this engine, you should at least have it balanced as an assembly. Please keep in mind that in most cases the small block chevy 350 heads will have a smaller combustion chamber than the 400 heads. Jul 18, 2010 you can not mix the 400 crank with a 350 damper or flexplate. But in most every case, the steam holes were clogged with rust. Jun 14, 2012 heads without steam holes can be drilled for them by using the correct 400 head gasket with steam holes as a template. Heads other than 400 stock heads do not even have the steam holes and you have to drill them yourself or have good automachine shop do it. Steam hole stopped up on drivers side engine block. When you get the new head gaskets lay them on your old heads to identify where the steam holes are and mark them. The steam holes were designed to rid the cooling system of steam caused by localized heating under some conditions due to the 400 block having siamesed cylinders meaning the cylinders ods are physically connected to each other due to the large bore size combined with the block having the same bore spacing. I feel that at the very least the clamping force of the head bolts will be compromised unless there is a viable way to fix this and get a good bolt hole again. The cylinder heads on the small block chevy 400 were prone to crack and the. I am getting ready to assemble my 400 sbc and was inspecting the block after it came back from the shop for a. If you filled your radiator with straight tap water, rust flakes will clog up the steam holes on the 400. Springs, no accessory bolt holes, small chevy, each 3 part number.

Common large chamber smog head, not a lightweight casting. Question about 400 sb without steam holes in the heads. The 400 has a bigger bore potential than a 350 and the bigger the bore the better heads you can put on it. Whats everyones thought on a 400 small block chevy. Heads fit all small block chevrolet engines, 283 400. I am tryng to save a small block 400 with 4bolt mains that has a crack between the steam hole and the adjacent head bolt hole, 6 locations. As for your 350 heads, they will fit, but you have to have a machine shop to drill the steam holes in the heads to match the 400 block. I know nobody plans to, but dont ever get 400 heads hot. Sep 03, 2017 62 studebaker engine gets a little warmer than i like. Jan 01, 2002 read the tech article on small block 400 cooling tricks, brought to you by the experts at chevy high performance magazine. Felpro 1144 sb chevy 400 head gasket, multilayer steel. Questions about 400 sb withwithout steam holes merged chevy.

There are one 316 and one 14 between each pair of cylinders. Also your 400 plus cube engines will make same power as smaller ones but at a lower rpm therefore reliability is increased if all things are equal. May 05, 2009 drilling new edelbrock heads for the vent holes needed on a 400 ci small block chevrolet. They came with 76cc heads and were relatively low compression,about 8. Got a nice 509 casting 400 block with 2 bolt mains. Sbc heads with steam holes can be used on other blocks without problem by using a 350 head gasket.

Can a 400 sbc block be salvaged with cracks that go from the steam hole into the head bolt threads. They are holes in the block and heads that aid in cooling the engine. They are an openchamber head, so to raise the compression ratio they either need to be planed or have domed pistons installed. Jul 09, 2018 i know about the steam holes, ive done some research on that. I have been looking for a 400 for a while now and have been burned on 2 so far 1 cracked block1 guy trying to tell me a 305 has the same casting number as a 400. The 400 block has siamesed bores and has no water flow between the cylinder walls.

Whether its the driving force behind a chevy platform, like ed cole intended, or being part of a rat rod ford model t rebuild, the influence of this engine is. I would say more than 50% of 400 block will have these cracks from the steam holes to the head bolt holes. You can also plug the 3 upper steam holes on each side, i have never run. I have a few questions herei have a 84 chevy shortbox. Looking to build around 800 hp with a gt 42 we have laying around. Stock 400s usually come with 882 casting heads, which flow pretty decent for street use with their 1. I tap the steam holes and insert a soft bolt in the hole, and i tap the large hole for a pipe plug as racer77 said, and drill the center for coolant flow. We accept cracked, warped, or damaged cores as your exchange. Im building an hd hot rod and wanted something with good torque to get it moving, definitely not autocrossing or racing it if i can make good power with a cam and intake id be glad to reuse. Checking on this for a friend of mine thats putting a 406 in his 88 chev fullsize. Repairing your cracked engine block bluedevil products. Professionally rebuilt pair of small block chevrolet heads. In the late 70s people didnt pay much attention to maintenance and proper coolant.

The overheating issue usually lies in the coolant passages sometimes considered steam holes which allow flow from the block to the head. Technical just bought a 400, what to do with the heads. We have seen over the years with 400 blocks many crank near the steam holes, because of the bigger bores and bigger main line it makes the webbing weaker and have seen cracks in those areas before, and have seen blocks crack from the head bolt hole to the cylinder making the block junk because the decks are thin as well as he cylinders. Chevy sbc 350 205cc 64cc angle hydrft complete cylinder. It usually isnt a huge issue or cause any problems with gasket sealing. I do remember putting together a 350 for him to put in his truck at that point and i think we reused those 350 heads that had been on the 400. Are 400 small block chevys with cracks between the head bolt. The small cracks from the steam hole to the bolt hole are kinda common. I was a little ticked to find that i have a hairline crack in the upper steam hole between cyls 3 and 5. May 01, 2011 drilling for steam all 400 smallblock chevy engines use siamesed cylinder walls, creating pockets in the cooling jackets that require venting. Used on the sbc 400, so may have steam holes and 1. I discovered a crack in the outer water jacket of the block about where the. Just use the 400 head gasket as a template for there locations. Small block 400 with steam holes aluminum block and heads or castiron heads.