SBC block Bowtie vs Dart

[Dave Koehler]

I haven't worked with SBCs in a while and have a friend trying to make a decision about which block to purchase.

We are eyeballing the Bowtie CNC steel capped 350 block versus the Dart.
Intended use is blown alky 355 in the low 7 sec range (dragster).

He Currently gets about 50 passes from a well worked stock block before cracking it from a head bolt hole through a cylinder wall. Sometimes detonation is obvious, other times it is not. Studs are correctly installed. No bottom end issues to date. It is just time to step up a little in the block dept.

We already realize that the Dart will need touched most everywhere but what about the Bowtie?
Do they actually get the decks squared up and the height as advertised at 9.025?
Are the mains sized correctly and uniform from one hole to the next?
and on & on.
If the above 2 items were met, then possibly all he has to deal with, shop wise, is the oringing and the bore/hone process.

Opinions and experiences please.

Thanks
Dave Koehler
www.koehlerinjection.com

[CNC BLOCKS]

I haven't worked with SBCs in a while and have a friend trying to make a decision about which block to purchase.

We are eyeballing the Bowtie CNC steel capped 350 block versus the Dart.
Intended use is blown alky 355 in the low 7 sec range (dragster).

He Currently gets about 50 passes from a well worked stock block before cracking it from a head bolt hole through a cylinder wall. Sometimes detonation is obvious, other times it is not. Studs are correctly installed. No bottom end issues to date. It is just time to step up a little in the block dept.

We already realize that the Dart will need touched most everywhere but what about the Bowtie?
Do they actually get the decks squared up and the height as advertised at 9.025?
Are the mains sized correctly and uniform from one hole to the next?
and on & on.
If the above 2 items were met, then possibly all he has to deal with, shop wise, is the oringing and the bore/hone process.

Opinions and experiences please.

Thanks
Dave Koehler
www.koehlerinjection.com

Both the Dart and the Bowtie blocks are nice the Bowtie block will need to be decked as we have found them under 9.025 and on the Dart when they deck the block they can't do it in one pass leaving a small step on the deck when match milling.

The Bowtie will not need the water holes matched to the head gasket as the Dart requires 7 places on each deck to opened up.

On the Dart the main line will have to line honed and the lifter bores as well as the Bow-ties are in spec but we break the caps down a check the size to make sure everything stays the same. On the Bowtie depending on lifter clearance they may need to be dusted out.

The Bowtie comes with a stud kit and the Dart uses a bolt kit for there mains

In most cases the Bowtie blocks are less work

We have the abilty to probe the blocks out before machining them in our CNC machine and as far as cylinder lacations and deck heights and lifter bore loctaions we find them about the same as they both need to blue print bored but between both blocks in most cases they are with in .005.

The last Bowtie we machined for roller cam bearings the cam tunnel from the factory was DEAD NUTS the best one we have see so far.

[Keith Morganstein]

The Bowtie block and basically all of the new chevy blocks are usually O.K.
At least good enough that I can tweak them in my "limited service" machine shop.

I haven't used a Dart block but I have a customer wanting a quote on one now.


I have a Motown in the shop that is next in line. After reading about some issues this will be checked very carefully!


CNC,

How much are the Dart sbc blocks, machined and ready to assemble including the cost of the block and machine work?

I want the "No fancy work price", just basic prepped and machined to assemble with confidence and no hassle.

I haven't worked with SBCs in a while and have a friend trying to make a decision about which block to purchase.

We are eyeballing the Bowtie CNC steel capped 350 block versus the Dart.
Intended use is blown alky 355 in the low 7 sec range (dragster).

He Currently gets about 50 passes from a well worked stock block before cracking it from a head bolt hole through a cylinder wall. Sometimes detonation is obvious, other times it is not. Studs are correctly installed. No bottom end issues to date. It is just time to step up a little in the block dept.

We already realize that the Dart will need touched most everywhere but what about the Bowtie?
Do they actually get the decks squared up and the height as advertised at 9.025?
Are the mains sized correctly and uniform from one hole to the next?
and on & on.
If the above 2 items were met, then possibly all he has to deal with, shop wise, is the oringing and the bore/hone process.

Opinions and experiences please.

Thanks
Dave Koehler
www.koehlerinjection.com

Both the Dart and the Bowtie blocks are nice the Bowtie block will need to be decked as we have found them under 9.025 and on the Dart when they deck the block they can't do it in one pass leaving a small step on the deck when match milling.

The Bowtie will not need the water holes matched to the head gasket as the Dart requires 7 places on each deck to opened up.

On the Dart the main line will have to line honed and the lifter bores as well as the Bow-ties are in spec but we break the caps down a check the size to make sure everything stays the same. On the Bowtie depending on lifter clearance they may need to be dusted out.

The Bowtie comes with a stud kit and the Dart uses a bolt kit for there mains

In most cases the Bowtie blocks are less work

We have the abilty to probe the blocks out before machining them in our CNC machine and as far as cylinder lacations and deck heights and lifter bore loctaions we find them about the same as they both need to blue print bored but between both blocks in most cases they are with in .005.

The last Bowtie we machined for roller cam bearings the cam tunnel from the factory was DEAD NUTS the best one we have see so far.

[highVE]

The cnc bowtie is much more $$$. But for what its worth i do prefer it over the dart. Don't get me wrong the Dart block it a GREAT peice. and i've used Big and Little M's, and the iron eagle ford and chevy. I love the quality. But the cnc bowtie is such a gem to work with!

Mike Theroux

[CNC BLOCKS]

To machine a Dart Little M block with steel caps all line honed, decked to your spec, blue print bore to your spec and plate honed, Lifter bores clearanced, water holes in the decks gasket matched, retap some of the oil feed holes, cleaned and ready to ship FREE for 2695.00

A 2503 Bowtie bock all machined will run 2895.00 as there is only about a 200.00 differance in price between the Dart and Bowtie,

And the Dart Little-M Sportsman block with Nodular Iron caps runs 2395.00 all machined and shipped FREE.

I see you don't live to far away and we can probably cut you a little better price if you stop by and pick the block up yourself.

We are also set up to blue print bore the cam tunnel for over size cam bearings or roller bearings if needed.

Thanks for the interest Carl Hinkson