Block filling

I was wondering if anyone had tried filling a cast iron block with molten cast iron.
The motor I run here in Australia is not available in a race version so we use factory blocks filled to the top. The problem is they only have four head studs per cyclinder with decks that aren't that thick.
My plan is to fill the block with cast iron and extend the studs further down into the new iron.
Can anyone see any problems with that or has someone tried it before.
The foundry said they can do it just have to try one and old one to check warp.
regards,
Brad

 

"Boat Anchor"!

This is what the NHRA rule book means by removable & Non-removable ballast? I'ld would sure call this Non-removable ballast! Just how much weight would it take to fill your block full of iron? And I though I had a boat anchor, Wow that will rewrite the team "Boat Anchor" in my book. Good luck with the fill.
Andrew

 

What have you used in the past to fill them?

 

In the past I have used Moroso block filler.
But my idea with filling the block with cast iron is that the head studs will be able to bite on the new cast iron deeper in the galley as opposed to the grout which will not hold a thread.
Brad

 

In 1979 I used fine cement in a .090 over BBC (spare motor for a Rodeck powered AA/DA), with custom made 1/2 head studs that had ~4" of corse masonry screw (7/16) attached to the bottom. I doubt they helped any, but the cement supported the thin walls. The added weight was not a factor as it had a larger stroke than the Rodeck and IHRA had a 4 pound per C.I. rule for iron block canted valve engines. We called it a "Redneck Rodeck", and it was great on slick tracks (there were many back then).

 

Do you mean everday garden varity cement? Is it stronger then grout?
Brad

 

Normal cement and foundation sand, mixed to a strong brew.
If you really want to, you could warm up your block and pour aluminium in, used this successfuly in cast iron cleveland heads to block of the heat riser holes.

 

I had thought of that but was concerned about the different expansion rate between alloy and cast iron.
Brad

 

on the billet, we actually used Marine Tech last year, but from what I understand, it depends on where the fill needs to be, and Lord knows I'm not even close to being an expert, but does anyone have any other experience with that?

(I guess it was used on Bucky's stuff A LOT too)

Nancy

 

Dont know whether it would hurt too much, we are pretty used to fitting up ali heads, manifolds, water pumps, timing covers etc on cast iron blocks often without water.

 

FWIW, some people who run vintage Flathead fords at Bonneville, take their blocks to a foundry and have them heat the block and pour them full of aluminum. Then they wrap the block with some kind of blankets and let them cool very slowly. You must remachine the block after doing this since everything shifts. They found they could drill and tap the head studs down into the aluminum and it cured their problems with the thin decks. It also stiffened up the whole block in the process. Hope this helps.

 

Brad, In regards to your material expansion rate differentials I would think that since aluminum expands more than cast iron when heated you shouldn't have a problem since the aluminum would be at it's largest expanded state when in the molten state. Hopefully you'd never get the motor that hot again in any situation! Something to think about doing would be to heat the block close to normal operating temp. you when bore and hone the cylinders. This is now commonly done in nascar but they have "hot-hones" that circulate heated water through the coolant jackets. Since you'll nolonger will have them you'd have to think of another source of heat.

 

Along the theme of filling the block with Aluminum....why not consider magnesium?
Lighter, strong, and maybe possible to have it pressure diecast into the block to increase density and eliminate voids?

or what about a slow setting epoxy resin with carbon fibres?

 

Back in the early years of Pro Gas. Dave Riolio (sp) started building bigger motors for this class (Big Block Chevs)....you have to remember this was before Dart/Brodix blocks..He was boring the motors 125 over (I believe).. He was filling them with an epoxy compound Devcon...I read an article on the build up, but they never told you which Devcon product he used.....His shop is in California

 

Devcon

I have an old Iron '57 392 Hemi (nitro) block thats filled to the top with Devcon and that stuff is as hard and tough as steel. It was filled 30 years ago, and its still good.
The motor has chucked rods 3 times and each time, they just flap around inside, chopping themselves up, but the iron block comes through ok!

Cant keep a good Hemi down!

 

Thank you everone for the replies and keep them coming. I am now looking into the aluminium option.
What type of Devcon? Will it hold a thread that can be torqued up to say 100FT lbs?
Brad

 

Don't know if it matters to you, but another thing to think about when filling the block is the ability of the substance you are using to dissipate heat. Aluminum will help dissipate the heat out of the block. I don't know if the regular block type filler will or not. Just something to think about.

 

I have heard of Devcon being used in heads (but unsure of tread hold as part of the use).

 

Devcon

I've seen Devcon used a lot in the aircraft repair business, from surface buildup to low stress thread repair. The stuff is pretty darn good, just make sure your surface prep and application is per the instructions.