Flex plate question ,

Les Szabo · Post by **Les Szabo** » Thu Jul 12, 12 3:06 am

Guy wrote:Heres Mark's Barracuda , a really well prepaired car.

Never seen it before, ...does looks real nice, like the Pro-Mod tyres, is that a 540 or 572 then?

Dave-R · Post by **Dave-R** » Thu Jul 12, 12 8:55 am

Pete wrote:I ran an 11.6 in a 2838lb '67 Dart with an iron headed 440 motor with a hydraulic 509 cam...........

Thank you Pete. Good to know I can still do the sums.

Blue · Post by **Blue** » Thu Jul 12, 12 9:19 am

My 3000lb Dart went 11.3 @119 with an all iron 440 with a .509 cam. At 2800lb with a good 60ft, close to 11 dead ought to be possible.

Dave-R · Post by **Dave-R** » Thu Jul 12, 12 10:39 am

If i was forced to name an exact number I would have gone for 11.4 with an experianced driver but with new car and new driver I would add a couple of tenths to that. Here is my coin down.

CliffTurner · Post by **CliffTurner** » Thu Jul 12, 12 5:38 pm

Les,if he hasn't changed the motor Marks Barracuda has a 512 low deck with ported Indy -1s , big roller cam and 13.5-1 comp. does go extremely well, 60fts in high 1.20s runs 9.20s
I'm pretty sure his brother Daves Valiant has gone a tad quicker 9.1
with 557 B1 motor

Les Szabo · Post by **Les Szabo** » Thu Jul 12, 12 6:22 pm

cheers Cliff.......thats some hp there and some excellent parts, proper Race Engines, they know what there doing alright

1stpop · Post by **1stpop** » Wed Jul 18, 12 11:37 am

just got my 400 block back from machine shop , there saying that the bores are 6 thou over ??? which is a big no no , so that block should have been bored out properly before assembly .

Post by **TyreFryer** » Wed Jul 18, 12 12:00 pm

Do you mean 60 thou Darren?

Ivor · Post by **Ivor** » Wed Jul 18, 12 1:03 pm

The machine shop could mean that the bores are 6 thou over a stock rebore size i.e. 46 thou.

In which case it would call for a rebore to the next size or a custom piston, which isn't the end of the world, Turnip can get them from Diamond.

1stpop · Post by **1stpop** » Wed Jul 18, 12 1:36 pm

that on my old engine that was build by someone for me !
the new builder said as a rule of thump 3 thou over standard bore is acceptable but this was 6 thou over and they had put standard pistons in it .
so wasn't going to win any race , like that and odd pistons lol

Post by **TyreFryer** » Wed Jul 18, 12 1:42 pm

Oh I see, so 6 thou over what rebore size?

1stpop · Post by **1stpop** » Wed Jul 18, 12 1:48 pm

right , i had a 400 built for me , stock bore , now we have pulled it back apart again as cam and lifters went less than 3 miles in. it had odd push rods , odd pistons and the block needed a rebore but they just put standard pistons in it .max this machine shop suggested was 3 thou over standard before it needs a bore this block was 6 thou over .

Post by **TyreFryer** » Wed Jul 18, 12 2:29 pm

At least the block can be rebored and used, it hasn't been rebored already, I think I read that if the block is 60 thou over it can't be used for a performance engine?

So at least you can sell the block and get some money back towards the new build.

Dave-R · Post by **Dave-R** » Wed Jul 18, 12 2:48 pm

The less you bore a block the stronger it is and the less power is lost through the cylinders flexing.

40 thou ( 0.040-inch ) is the most you should bore any Mopar block out to be safe. Although there are many stroker motors out there that have been bored to 55 and 60 thou I personally wouldn't do that without knowing exactly how thick the cylinder walls are.

There is some variation from block to block as casting moulds were used several times over before replacement.

Pete · Post by **Pete** » Wed Jul 18, 12 3:57 pm

As ever, before machining CAREFULLY inspect the block for hairline cracks on the water jackets (including in the Valley) and the mains near the cam gallery.

If any are found in the cam/mains webs then instant dead block............

ARP mains Studs are always a good idea too......