Time for new engine

[moparracer]

After having lots of fun the first part of racing season, it all started going down hill in July. I developed an internal water leak. First time around new head gaskets and a dose of block sealer cured it for 5 weeks. Then it happened again, more water. Tore it apart again and pressure checked the heads, put it back together and ran another couple of weeks. Leaked again. This time there was no stopping it.

Dragracer interuptus.

Last week I tore it all down and pressure checked the block. In cylinder 6, I could see a little tiny bubble form. So, I got a pin and poked it. The pin went through the cylinder wall! Clean through! In all I had 3 cylinders with holes. ](*,)

The moral of the story? Don't bore a 72 440 +.060. I had a friend I used to race with that had the same thing happen years ago, so i called him and he still had his junk block. Both blocks were +.060, both blocks were '72, they were cast 4 months apart. Both ended up with pinholes in multiple cylinders. Coincedence?

The plus side is I have been wanting to make more power, just not this soon. Time to get busy, spring is coming.

 

[mikesduster]

if you need another 440...let me know!!! :thumrigh:

 

[lemonboy69]

Yikes... thanks for the heads up! I was thinking of taking my '74 440 .060" over... maybe I'll just stick to .040" over and keep it safe. It's getting a stroker kit anyways, so MORE power!!

Off topic and out of curiousity - how much does your Duster weigh? I'm looking to put my '67 Fastback into the 10's... any thoughts?

 

[Mopower71]

Joe, What's the plans for the new engine?

 

[moparracer]

Yikes... thanks for the heads up! I was thinking of taking my '74 440 .060" over... maybe I'll just stick to .040" over and keep it safe. It's getting a stroker kit anyways, so MORE power!!

Off topic and out of curiousity - how much does your Duster weigh? I'm looking to put my '67 Fastback into the 10's... any thoughts?

Before I switched the 8 3/4 to a Dana 60, ladder bar/leaf spring set-up, and added a factory alternator, the car with me in it weighed 3398. I haven't weighed it since these additions so I'm guessing just over 3500 lbs race weight. The car is all steel with the exception of the front bumper.

Plans for the new engine are just that right now. I just dug out one of my spare blocks which is a standard bore '68. Taking it to the machine shop to get cleaned and magged. The rotating assembly in the other engine is still fine but I don't want to take the new block +.060 the first time out. So i will just put this stuff on the shelf. I'm thinking 4.150 crank, good rods and CP pistons. A partially filled block, aluminum main caps, just a good reliable set-up. Gonna have to use the old heads,cam, etc for now because of the sizeable investment in the short block.

Or I could just bore the new block .060 and bolt it all back together and be done in a couple of weeks for cheap. Decisions, decisions,decisions

This kinda sucks because this engine has fresh resized/bolts Direct Connection rods, bearings,rings,oil pump, chain, valve springs and seals. All only has 69 1/8 mile runs and a few 1/4 mile.

 

[moper]

I have bored a few blocks to .060. It's still considered a std oversize. Year of block means nothing. Some are good, some arent. The only big difference really is the material. The earlier iron is not as good as post '72, which is generally when the "thinwall castings" came out. (maybe it was '73..Dont recall...) A lot depends on the shop too. If a boring bar is used, it can only index off the center of the exisiting bore. The factory machining we are all aware of, as far as accuracy and quality go...If the shop used a BHJ fixture, or anything similar, than bore centers can be corrected. If they are bored in the "right" spot on a block with bad coer shift, you can have poroaity leading to your problems. If possible, dont go +.060 for anything. If you do have to, either have the sonic check done, or roll the dice. For real performance builds, especially with longer than stock stroke, and shorter than stock pistons, I try to only use .030 over. I havent had any issues with .060 over engines...but I'm sure it's a matter of time.