Filling of block water jackets

[Chambers]

I am interested in info and experiences on filling/partially filling the lower cyl area.What is the best substance and would it pose a problem on an already machined/assembled motor? I've read some stuff on the old board but have to consider the inconsistant info of the old board. how would cooling on the street be affected? If done(filled) after machining how could the product cause distortions of cast iron blocks,if it were to expand that much,seems like different substance should be used. I've used a product in the body shop industry that is called marine-tex and there is a liquid version that is so hard and sticks so well I think it would be the perfect filler. Need some real input, Thanks.

[Chambers]

I am interested in info and experiences on filling/partially filling the lower cyl area.What is the best substance and would it pose a problem on an already machined/assembled motor? I've read some stuff on the old board but have to consider the inconsistant info of the old board. how would cooling on the street be affected? If done(filled) after machining how could the product cause distortions of cast iron blocks,if it were to expand that much,seems like different substance should be used. I've used a product in the body shop industry that is called marine-tex and there is a liquid version that is so hard and sticks so well I think it would be the perfect filler. Need some real input, Thanks.

[Gach]

First off, you can not fill an already machine block" unless you intend on re-boring. The reason why it distorts, is because in some area's ( if you've ever had a block sonic tested you'll see what I'm saying ) is very thin. Most 455 blocks will end up as thin as .145 wall, .180 is the minmue you should go, and that's even with filling the block. Expanding concert with a wall that thin ( an it may only be in some area's that it's that thin ) will make the cylinder out of round, which will effect ring seal a great deal. Usually you only need to fill the block to the freeze plugs, it will not effect street driving, actually will run a little cooler. I can tell you from experience that it's must do thing, if your planning on making over 650 hp. A 455 block is nothing but a .030 over 400 or 421-428 block, so your ending up with, if you go .060 over a .090 over 400 block. A 455 block is One of the worst blocks to use if your trying to make over 650 hp, and up in the 700-1000 hp range.

Chambers, do yourself a big favor, and take that steel crank, and have them turn down the main journals to 3", an use a 400 block, with steel caps and studs" that's going to be your cheapest way out. Other wise you'll have to buy another set of pistons, and that block even with a steel crank will not take the hp your going to make with that blower motor. The 455's are very weak in the #3 main
journal area, and will crack all the way up to the cam bearing. Maroso sells hardblock, and works really well, the block has to be level, when you pour, an will need some thing to fiberate the block in order to get all the air pockets out of the mix. I've done allot of hard core racing, and know allot of
guys as well as I who have been through blocks, cranks. It's is very hard trying to fine a good 455 block for making allot of hp.



[This message has been edited by Gach (edited 02-12-2000).]

[Vascar]

I've seen the 455 block crack in the 2 and 4 journals. It was a two bolt and was ran for two seasons before it cracked. Splayed steel main caps can help prevent cracks.

The guy who fills our blocks around here uses cast iron filings in the machine grout and then cures them for a month or two. He also heats and cools the block so the grout takes a set, then comes machining. This guy has been doing this for years with no failures.

[Chambers]

Gach, so if I understand you correctly , If I take a 400 and bore it .090 so I can use my .060 455 pistons, won't the cyl wall end up as thin as the 455 at .060? Is there any difference in block strength between the 400 and 455, bore size aside? What would be the highest level I could hardblock and still street drive? I have an extra 455 std bore block, would I be better off hardblocking it and staying at std or.030? Would I have a chance of hardblocking my current 455 and rehoning the cyls? How much distortion should I expect with hardblock? Why can't I use a different filler that wont swell as much? I have other questions and appreciate your advice.