Visit The Dirt Forum for More Information

Author Topic:   bad block- use or not
posted January 24, 2004 07:26 AM
well I tought I got a deal but when I took my recently purchased 400 block back to the machine shop that the guy that sold itto me said it just left from . The machine shop was familar with the guy and the block and said " you do know that it has a craked main right?" Well I went off the deep end since this was susposed to be a freind who sold it to me . It has a very small crack right where the oil hole is on the main. I asked that if he knew it was craked why would the machine sop go ahead a bore and install cam bearings and he said he didnot relize it untill after he installed cam bearings. Sounds like a lousy machine shop to me but he is actually a reputable builder. Anyway he said that itwould probly be fine anyway o use but I think it will only destroy itself over time. Also how hard will it be to cool a 400 0.40 over?

posted January 24, 2004 01:28 PM
the crack i'm not so sure about but 0.40" over size is what our engine is and we have not had a cooling problem. we do run alcohol, and use the steam holes in the heads, with a racing water pump (stewart).

posted January 24, 2004 01:52 PM
the crack in the bolt hole will upon getting hot expand ansd loosen up the bolt then in turn spin a main bearing is it a 4 bolt main or two? Well no matter i would not use it! Why take a chance on blowing it up and loosing everything when you can get another one and not have anything to worry about! Because you know just as well as I do that everytime you race you are going to worry about it.

They only way that i would use it would be for a claim race MAYBE

you never know how fast you are going when your in the lead, until you blow the announcers hat off!!!

posted January 24, 2004 07:35 PM
yes it right at the oil hole not bolt hole I would never use it there.

posted January 25, 2004 05:14 PM
alright alright can you say a blonde brain FART lol
Welll if the crack is small enough then you could drill it out so the crack will stop. If it is too big then DONT use it the crack will keep going through the galley all the way out to the water jacket
Sorry about the previous statement i read it wrong you guys know a brain fart lol

[This message has been edited by iowa_dirt_track_girl (edited January 25, 2004).]

posted January 25, 2004 05:28 PM
junkit! i wont take a chance.

posted January 26, 2004 09:13 AM
I wouldn't junk it....I would take it back to the person you bought it from and DEMAND MY MONEY BACK!!!!!!

posted January 26, 2004 09:43 AM
Get a aftermarket cap. Never mind, wasen't thinking.

[This message has been edited by Hobby152003 (edited January 26, 2004).]

posted January 26, 2004 02:02 PM

Peace of mind and kick **** all season. Total cost $500-$600 and one spare boat anchor.

Worry constantly, think every sound was a main knock, and b!tch when it throws $3k of associated engine parts out the oil pan. Total cost $5000-$6000 (need all new parts once the crank snaps in half at 7000 rpm when that main drops out) and miss at least 3-4 weeks of racing while a new block is machined.

Not much of a decision to me.

Ego Racing
posted January 26, 2004 02:41 PM
We have had a simaler problem in a road race car, we drilled a small hole at the bottom of the crack to stop it and find the exact depth of the crack then grind a V in the crack to open it slightly. We had a machine shop that specialized in casting repair drill the oil passage larger about .25 inch past the damage, insert a sleve that pressed into the passage and drill to proper size then weld the casting back together and recheck the sleve. I was an antique racecar so the parts were not that easy to find or we would have replaced it. The problem never showed up again and the car is still running in the classics racing series after 7 years. The cost was about $150 if I remember right.

Moral of the story..... Have it checked before you buy. If they object to it being checked they are hiding something.

Back to the Archives