hey guys i've saved up enough money to buy an aftermarket BBC block. my question is, which brand would you go with, Dart Big M, World Products Merlin III, or a GM Bowtie block? i've heard good and bad about all of them, just wanted to get some opinions from you guys. im undecided on weather to go with a tall deck or standard deck, and also on weather to go with iron or billet main caps, so some input on that would be great also.
thanks,
Chris

What displacement and what intended usage engine do you want to build? Any of the 3 are good blocks. If its going to be any sort of street engine I would use the iron caps. Tall decks can also have issues espeically with the headers and raised port heads.

I consulted two different Engine builders and they recommended the Dart block but i truly think any of the three would make a great starting point. If you want to put an oversized cam in the block then the aftermarket blocks can be opened up to a larger size but otherwise all are comparable. I think the Merlin 3 blocks have dowels in the main caps. The Merlins are the cheapest by a hundred dollars or so over the Darts and the "CNC" Bowties are the most expensive but i've heard they come with a sonic test sheet showing how thick all the cylinder walls are.

I've had 'em all and the choice would be between the Dart and Bowtie, IMHO. If you don't need steel caps, the Dart is your best bet. My experience has been that they have better customer service that World. If you are going to hit it really hard, the Bowtie only comes with billet main caps and is cheaper than either of the other 2 when comparably equipped. My Bowtie came with the sonic sheet and with exception of the siamesed cylinder walls, I'll have a minimum of .275" at 4.625". If I build it at 4.500, I'll be over .300 all the way around. The GM casting has less flash and surfaces are smoother. Most of the high end builders I know use the Dart pretty much exclusively. By the way, RMRE doesn't even sell the Darts with billet caps unless specifically requests it as the massive splayed nodular caps are generally waaaay more than capable of handling what most of us can throw at it. Good luck with your build-up!

G.M., Dart, World, in that order. The Bow-Tie blocks are available both ways with nodular or steel caps. Depends on the part number ordered. We keep dozens of each on the shelf here (more of the G.M.'s though). Recently got a batch of Dart "Little-M"'s with timing cover bolt holes drilled through to the water jackets, weren't too happy about that. It wont affect the performance however. Customer service everywhere consists of nothing but "denials" or "you got the only bad ones, we have no problems" syndrome. Thanks, Gary in N.Y.
P.S. Inter-mixing (new) parts on new jobs coming in the door here is going to see a dramatic change in the coming months. We have too many issues of "vendor-mismatch" happening. I just took a "383" stroker kit" in from a customer with an Eagle crank, Scat rods, and a set of SRP's. The pin ends of the rods are too close to the pin bosses, the radiused portions of the skirts are hitting the c'weights, and the bottoms of the pin bosses are hitting also. Due to this one particular issue we are going to try to avoid using any 5.700" rods anywhere when possible and substitute 5.850's or 6.000's. The money the customer thought he "saved" buying this kit is not going to amount to a "hill-of-beans" next to the amount he's gonna shell out to fit it all together. Try to get the all the "right" parts the first time. It's all new parts, but it's been "resold" to friends a few dozen times, so this customer is stuck with it. I only added this to make people aware of the add'l work they MAY encounter on performance units.

With all the blocks we prepare the Dart seems to be the most popular both the SBC and BBC and we don't carry dozens of each on the shelf like GOFAST but we try to keep one Dart Little-M and a Bow-tie and as mentioned the Bow-ties are better looking on the out side then the Darts.


GOFAST where are you located on the Island as the Sunnen rep wants to come see you and wants to see your shop but you post no phone numbers or address or even a bussiness name but you have dozens or each blocks on the shelf how do you move the stuff??????????? So whats up with that??????????

Both of the local engine shops I've used, along with Reher Morrison recommend the Dart over World.

With that said, I know Jason (Dragracer) had some issues with his Dart block, but they were not related to structural integrity.

Not sure where the GM fits in but the prices I've seen for it have been higher than the Dart stuff.

I bought my Merlin III block thru Scoggin-Dickey. Dropped shipped directly from World...I bought the 4.500", 9.800" finished bored model with cam bearing/freeze plugs installed.
All finished machined specs/dimensions were right on. Very satisfied with the quality! :thumbsup:

Here are a few pics of my CNC Bowtie, 9.8, 4.560 O-ringed

http://www.brumfit.com/photos/blockbottomstuds.JPG
http://www.brumfit.com/photos/blockstuds.JPG

Am I missing something or does that Bow Tie block not have any holes to accommodate for oil to drain back to the pan? Just curious. Also, what are the three bosses (with holes open to the right side of the block) in the bottom of the valley.
Rowdy

pssst get a brodix alum block they are much more shiny. ;)

Look closer at the first picture, especially by the cam bearing, to the left, big enough drain back holes for ya?????
The 2nd pic is kind of dark to see thru the drain lots, but they are there if you really look long & hard at the pics, good luck!!

Ooops, the 3 bossed holes in the valley, hmmm, don't the engine builders use those holes to hold screw drivers and L shaped alen wrenches?????LOL
Not sure but I am sure there is a use for them, I too am curious what they are for, maybe for a windage tray hold down?

John

im planning to build a 540, its going in to either my 68 chevelle or my 70 chevelle. i've heard that the nodular caps are better than the billet caps on a street engine because of the difference in expansion and contraction rates with the billets. sounds like i'll either go with the bowtie or dart block.
thanks,
chris

im planning to build a 540, its going in to either my 68 chevelle or my 70 chevelle. i've heard that the nodular caps are better than the billet caps on a street engine because of the difference in expansion and contraction rates with the billets. sounds like i'll either go with the bowtie or dart block.
thanks,
chris

We don't see any differance between the 2 as far as wear issues to the bearings I belive if there is any differance its very minimal the nodular cap blocks tend to be cheaper. And the Dart I feel would be the better peice.

I only have one on the shelf not dozens of each like GOFAST!!!!!!!

Someone please explain for me - why don't the manufacturers clean up the casting flash at the lifter galleys while prepping the block? I would think this would be a 5 minute had grinder operation - done before the cam bearings are set in.

Someone please explain for me - why don't the manufacturers clean up the casting flash at the lifter galleys while prepping the block? I would think this would be a 5 minute had grinder operation - done before the cam bearings are set in.
Probably for the same reason GM didn't... :confused:

If you have the opportunity to see ALL the "major" manufacturers blocks, I'm talking only cast iron here, side by side, you start to get a better idea of the levels of quality each one has achieved. And I'm not talking about the machining operations either, that's for a separate issue. I'm talking about
appearance only. I have at the present time 30 new blocks (that's right CNC, 30, I had 32 yesterday) to prepare. 15 are destined for jobs and 15 we'll sit on for a time. A mix consisting mainly of G.M. (both Bow-Ties and MK-V's) and Darts. The Darts seem to have a fair amount of rust already, just from sitting. The G.M.'s (sitting in the same conditions) appear the same as when they were delivered (still clean). I believe it has to do with the "ore" they're using for the castings. The castings themselves are of a higher quality from G.M. The amount of porosity I see in both the Darts and Worlds just doesn't "fly" with us. Many out here would be shocked to know how many new assemblies have been delivered through various vendors, over the years, with sleeves already installed. It all has to do with Q.C. Thanks, Gary in N.Y.
P.S. We have some "cast main cap" units off the dyno with 1250+ HP and a high-end Nitrous system ,which we didn't test with, and have no problems at all. Actually, if you look at the block in the photo here with the "O" rings, we feel that's no longer necessary under 1500 HP due to the "Cometics" and the "MLS's". We tested a World block recently, without the inner head bolt bosses (the block didn't incorporate them), with over 15:1 compression and no problem. We even reused the gaskets as part of the test. Personally I didn't believe it would get past the dyno. I just had a conversation with them about using the gaskets with an already "O" ringed setup. I told them what we found from testing. They can be setup to be used on those blocks with no failure.

Ya, I cleaned up the lifter galley with a dremel after I took the photos

Are there any other negatives in regards to the Dart in addition to porosity and faster corrosion compared to the bowtie.

Are there any other negatives in regards to the Dart in addition to porosity and faster corrosion compared to the bowtie.
The integrity of any of the castings is no issue, as we've done a number of all of them at 1400+ HP (BB's) with absolutely no "concrete". Thanks, Gary in N.Y.

CNC BLOCKS and GOSFAST.................You guys are a trip!

Sounds like a big boy peeeeeiing contest. All we need now is for Wolf to
set the record straight. :)

Don't you ya just love the Internet ?

Only issue I had personally with the Dart Big M was with a stripped head bolt hole. My machinist had run into that with another Dart Big M as well. Seems the taps may have been getting worn. Needed a heli-coil for that.

Funny that the issue of rust came up, because I live on the West coast, not far from the ocean, and one thing I did notice was how rust free the blcok stayed in comparison to a GM small block that I'd worked on earlier. As far as casting quality, I found the blcok to remarkablly free of casting flash. Water jackets were all smooth as far as I could check, with no obvious porosity on embedded casting sand. Nice block.

Who knows, as I mentioned, just my very limited experience with one block.FWIW.

John

Sounds like a big boy peeeeeiing contest. All we need now is for Wolf to
set the record straight. :)

Don't you ya just love the Internet ?
=
I have no opinion :D Well maybe one or two on occasion,,,,
Hell,,, I don't even have room for 30 blocks,,
But I do have two Dart 9.800 blocks sitting here along with a few of their small blocks & none of them are "rusting"??
Pretty nice piece in my opinion,,, oops, there's one now,, damn,,, :rolleyes:

As for the front cover bolts going into water on the small blocks, this is a non issue.
They been that way as long as I can remember & I just seal them.
And another "issue" is you usually need to retap all the pipe threads in the block,, again, nothing serious if you know about it ahead of time, Bit of a nuisance though.

I do not use World blocks.
I try not to use World anything but I have fixed a few. Just fixed one of their aluminum 427 "crate" small blocks with some interesting machine work that was bought as a complete short block through one of the mail order biggies & reported to be built by the maker (no, not God although rumor has it he also resides in NY & builds engines,,, :D )

Showed the customer a Brodix block & after he got done cryin a while he is "considering his options"
Putting the two blocks side by side is a real eye opener,,
Think I will stick with the Brodix for an aluminum piece,,

Totally off the subject for a moment, just to put things in a little better light. I don't know where most of you are out there, but I see some members from the Long Island area and any of them can confirm what's here. Posted up here from time to time some say they have to drive a distance to get machine shop services or engines built. Just on the island here, we have OVER 100 machine shops/engine builders. You could probably come here with an empty "18 wheeler", drive around for awhile, and leave with maybe 3000/4000 new castings. One shop alone has probably 1500/2000 "on the shelf". So you can see why when you have 30 blocks "kickin' around" some shops would be "out-of-stock" with that number. I'm sure somebody here from the island will speak up. Thanks, Gary in N.Y.
P.S. I'm not postin' numbers here to impress anyone, it's just fact. A few customers in the door in the last week brought in some (4) "early" 4 B.M. BB's. We gave them, on a heads up trade, (4) brand new MK-V, 4.250", 4 B.M.'s in exchange. These particular blocks cost me (new) well under 1000.00 ea. The "trades" will find their way into restorations. There's simply a lot of "iron" in this area. Thanks, again.

Totally off the subject for a moment, just to put things in a little better light. I don't know where most of you are out there, but I see some members from the Long Island area and any of them can confirm what's here. Posted up here from time to time some say they have to drive a distance to get machine shop services or engines built. Just on the island here, we have OVER 100 machine shops/engine builders. You could probably come here with an empty "18 wheeler", drive around for awhile, and leave with maybe 3000/4000 new castings. One shop alone has probably 1500/2000 "on the shelf". So you can see why when you have 30 blocks "kickin' around" some shops would be "out-of-stock" with that number. I'm sure somebody here from the island will speak up. Thanks, Gary in N.Y.
P.S. I'm not postin' numbers here to impress anyone, it's just fact. A few customers in the door in the last week brought in some (4) "early" 4 B.M. BB's. We gave them, on a heads up trade, (4) brand new MK-V, 4.250", 4 B.M.'s in exchange. These particular blocks cost me (new) well under 1000.00 ea. The "trades" will find their way into restorations. There's simply a lot of "iron" in this area. Thanks, again.

Gary

Again where the hell are you located and whats the name of your bussiness as there is guy I know wants to look you up in the next month or two. OR IS IT TOP SECRET LOL.

Isn't this fun?

Well. I have an old Merlin II in my car and it's been fine. The Darts were still on the drawing board when I got mine and the Bowties were not of the highest quality at the time and even at that both the Merlins and the Bowties were awful hard to find. This was about 5-6 years ago. I looked for a long time to get one.

Anyway, the casting quality of the Merlin was very nice. I also noticed the "niceness" of the metal immediately and listened to machine shop whine about trying to bore/hone it due to metal density. Of course they knew it would be that way, just had to take things a little slower. The only other machine work needed was to deck block as World left a good bit of metal on it...like .030 or so.

Recently I got a chance to help with a Dart in a 632" build. I gotta say that the quality of that block was VERY nice. All the bolt holes were nice and everything fit nice. This one was pretty darn clean as far as casting flash.

And I live in Houston with a "slight" humidity issue and I didn't see any rust on them. Maybe I didn't clean all the shipping slime off well enough huh???


JIM

=Showed the customer a Brodix block & after he got done cryin a while he is "considering his options"
Putting the two blocks side by side is a real eye opener,,
Think I will stick with the Brodix for an aluminum piece,,

I was thinking about putting some lipstick on my brodix block and marrying it. It's THAT pretty!

I was thinking about putting some lipstick on my brodix block and marrying it. It's THAT pretty!

How about some pics

How about some pics

Here is a pic of one we machined and asembled for a customer (very nice peice) bottom side

http://i7.photobucket.com/albums/y276/CNCBLOCKS/blowerengine015.jpg

Top side
http://i7.photobucket.com/albums/y276/CNCBLOCKS/blowerengine003.jpg

Other side

http://i7.photobucket.com/albums/y276/CNCBLOCKS/blowerengine002.jpg

Finish product this engine is on its 5th year

http://i7.photobucket.com/albums/y276/CNCBLOCKS/blowerengine010.jpg

Ohhhh, that is purdy