400" with DART LITTLE M BLOCK.

[Fatman]

got a 400+ (4.145x3.75) motor going together with a dart little m block.

Anything to watch out for with this block or to make sure of before assembling. Plugs? bolt holes tapped etc?

Also is it worthwhile radiusing the oil gal to and from the oil filter?

thanks
fatty

[Jason G]

Be sure to check the threads on every hole. I had an oil pressure port on a Dart Iron Eagle that was not tapped and turned out to be drilled oversize. Took a 1/8" NPT heli-coil to fix.

It will need an align hone, lifter bores will likely be on the tight side, bore and hone cylinders, and deck.

[CNC BLOCKS]

got a 400+ (4.145x3.75) motor going together with a dart little m block.

Anything to watch out for with this block or to make sure of before assembling. Plugs? bolt holes tapped etc?

Also is it worthwhile radiusing the oil gal to and from the oil filter?

thanks
fatty

Those blocks have to be line honed to spec as they come through under the low side and so do the lifter bores and check all the pipe taped holes as you will find that there no deep enough and debure the rear thrust area and set your head gasket on the deck as there are 7 areas on each deck that have to be opened up with a grinder.

[oldhead]

Been using mine a year and a half, no problems going to gether, a couple of thousand miles and some bumper to bumper traffic in 90 plus temp. with NO steam holes drilledmade 1130 on the dyno.....OLDHEAD

[Fatman]

Thanks as always

What is the acceptable clearance for a solid roller lifter to the lifter bore?

[Fatman]

Me again

With regards to the line honing, is it possible to not line hone and used a bearings with extra clearance? Is this an acceptable way to do this if the clearance comes up right or does it result in to much crush and cause problems, if so, what probelms?

[Matey79]

This is just the procedure I have done on the Dart Small Blocks and what I have seen. Be sure to check and maybe grind some on the four corners of the deck which are for drain back for the cylinder heads into the valley. The line hone varies, but is always tighter than the tight side of the GM spec. .8439 is the number we usually hone the lifter bores to. World Products Motown blocks lifter bores are usually rough bored to .8447 !

[Wolfplace]

Me again

With regards to the line honing, is it possible to not line hone and used a bearings with extra clearance? Is this an acceptable way to do this if the clearance comes up right or does it result in to much crush and cause problems, if so, what probelms?

=
On the lifters if you have a thou you should be fine.

On the mains
Most every one I have done has varied from about .0005 to .001 under the low limit & I have never run one without line honing.
Only complaint I have is it would be nice it they were all the same damn size regardless of what it is. Makes life a lot easier when honing.

If you can get it to about .002 of vertical oil clearance & still have plenty of eccentricity to form an oil wedge I don't see why it wouldn't work but I have never actually tried it.

[RZ@D]

Most every one I have done has varied from about .0005 to .001 under the low limit & I have never run one without line honing.
Only complaint I have is it would be nice it they were all the same damn size regardless of what it is. Makes life a lot easier when honing.

How can they be different from cap to cap? Or did you mean from block to block?

[Wolfplace]

Most every one I have done has varied from about .0005 to .001 under the low limit & I have never run one without line honing.
Only complaint I have is it would be nice it they were all the same damn size regardless of what it is. Makes life a lot easier when honing.

How can they be different from cap to cap? Or did you mean from block to block?

=
Cap to cap & you will have to ask Dart why.
If you want them all the same size when you hone it's kinda nice to start with the same size holes,, regardless of what the Sunnen sales rep tells you

I have one sitting here that is .0008" different from smallest to largest.
Not a huge deal just a bit of a pain in the ass

I certainly would not care if it were block to block

[CNC BLOCKS]

Most every one I have done has varied from about .0005 to .001 under the low limit & I have never run one without line honing.
Only complaint I have is it would be nice it they were all the same damn size regardless of what it is. Makes life a lot easier when honing.

How can they be different from cap to cap? Or did you mean from block to block?

We machine alot of Dart blocks and we check the housing bores then disassemble the caps debur them and clean them, Lube the bolts with ARP lube reinstall them and we don't really see the demension change much and we line hone and leave a few tenths and loosen the caps and retorque them to see if they repeat and finish line hone to size.

[Wolfplace]

Most every one I have done has varied from about .0005 to .001 under the low limit & I have never run one without line honing.
Only complaint I have is it would be nice it they were all the same damn size regardless of what it is. Makes life a lot easier when honing.

How can they be different from cap to cap? Or did you mean from block to block?

We machine alot of Dart blocks and we check the housing bores then disassemble the caps debur them and clean them, Lube the bolts with ARP lube reinstall them and we don't really see the demension change much and we line hone and leave a few tenths and loosen the caps and retorque them to see if they repeat and finish line hone to size.

=
HI Carl,
Basically do the same deal but the last three varied from hole to hole with this last one .0008 different from big to small as I said.
Two were the Sportsman's & one was the Billet
Don't have a problem with them repeating much when removing for cleaning & retorquing for final hone etc,, but as you know when you start with different size holes you get to "play' a bit to end up with them all the same when you are done.

What I am saying is the hone will not fix holes that are different sizes even though some of the Sunnen sales guys tell you they will.
They all need to be pretty close to start to end up the same size .
And even then you sometimes need to be a bit "creative" to keep them at size,,,,

Again, not a big deal just a bit of a pain & three in a row was a little annoying along with all the other little peculiarities like all the tapped plug holes

Don't get me wrong, I am not knocking the block, I think it & the BowTie are the best iron blocks out there.