Page 1 of 2 12 LastLast
Results 1 to 10 of 11

Thread: Dart vs Merlin

  1. #1
    Taylorman
    I was wondering who makes a better block out of Merlin or Dart. Are there any differences or if one is better than the other?

  2. #2
    steelcomp
    For all intensive purposes, they are the same. It depends on what you want do do, how much HP, stroke, deck ht, etc. Dart and World Products (makers of Merlin products) used to be owned by the same people. World Products was the part of Dart that was responsible for most of their cast iron products with Bill Mitchell in the design corner. Dart was more focused on the hard core race products, including aluminum heads and manifolds. Dart also casts a lot of aluminum parts for other companies. A while back, the two companies seperated, and are now independant of eachother. It's still my understanding that the Dart products are more directed at hard core racing, but I don't know how different the two blocks are, except that the Dart is probably available in more configurations than the Merlin. Someone else might know better. You could call the two companies and ask.

  3. #3
    Fiat48
    Things may have changed but I liked the dart because it was machined more accurately (to put it mildly) and the extra head bolt locaters for the heads. But I liked the way Merlin dowel pinned the main caps better than Dart just using deeper locaters.

  4. #4
    LakesOnly
    Things may have changed but I liked the dart because it was machined more accurately (to put it mildly) and the extra head bolt locaters for the heads. But I liked the way Merlin dowel pinned the main caps better than Dart just using deeper locaters.
    Poor Fiat48...how many times have you answered this question? More than the four times I have seen, I'm sure.

    LO

  5. #5
    UBFJ #454
    For Cast Fe Alloy Blocks I prefer the Dart "Big M's" as I feel their alloy is better. For Al Blocks I like Donovan's, Arais or, Rodeks, depending on the motor to be built (N/A or Blower).
    Note with any of them you need to do quite a bit of machine work to "Race Prep" them ... Especially with the Dart "Big M's" ... Particularily as has to do with Modifying their "Priority Oiling System" for use of Big Lifters like Jesels.

  6. #6
    Infomaniac
    I will agree with Fiat. I like the mains on the Merlin III and the bosses for the extra head bolts on the Dart Big M. I like the Dart's taller lifter bores also.
    Looks like we need a hybrid block Maybe call it a Derlin or a Mart?
    I have lots of pictures Taylorman. Look at the end of the Trident engine build in the How To section of this site for Merlin III pic. I can dig up some Dart pics. I did take as many pics of Trident #2 with a Merlin block. Just have not posted many.

  7. #7
    Unchained
    Fiat48,
    I guess you fared a lot better than me on the Dart heads.
    I bought a set when I originally assembled my engine in 2000 and they were some of the worst workmanship I'd ever seen.
    I bought the heads completely assembled. ( big mistake )
    First, after I got them bolted on the BRAND NEW ARIAS BLOCK I found that the pushrods were a long way from lining up.
    I ended up with a carbide burr doing some major hogging to make sufficient clearance for the pushrods to line up with the rockers. I must have used every four letter word I knew after buying what I thought was the best and found out how crude the machining was.
    So I ran them three seasons with an 8-71 blower.
    At the end of the third season I removed them for inspection and brought them to a local performance engine rebuilder for a freshen up.
    He calls me and tells me that most of the valves are bent and no good.
    I knew that they NEVER floated and there were absolutely no impact marks on the pistons.
    The dart boys who assembled them just dropped the valves into the holes that WERE NEVER GROUND and then proceded to install the springs.
    They never hit concentrically but bent to conform to the off center valve seats.
    I had checked the compression many times and it was actually real good so they must have bent to fit the hole right off.
    I'm real lucky that the valve head didn't break off and scrap the engine.
    I called Dart and got a lot of "well I just can't imagine how that could have happened"
    Besides the major problems the heads were never deburred after the machining and they never even blew the chips off before assembling. Didn't make much sense putting them into a plastic bag to ship them.
    To compare to it the Arias Century aluminum block was a machining work of art.
    Next time I'll try Brodix heads and assemble them myself.

  8. #8
    TIMINATOR
    We stopped using ANYTHING DART when about 6 years ago, I was at the SEMA expo and asked why the quality control was so poor. I related that we had to remachine the decks,hone the guides,and touch-up the valvejob on every head we sold. The west coast rep told me in front of about 20 others "we sell everything we make,we're putting in more machines to produce more product,and we're behind on deliveries, we're making money hand over fist,so why bother?" I have not purchased anything from them since.
    On the other end of the spectrum you have AFR, the highest quality, and best quality controlled head I have ever used. They spend a BUNCH on advertising, have a knowlegable, personable staff, and an abyssymal delivery history. It took them almost 3 MONTHS to supply the LAST set of common 195 SBC street heads we bought. P.S it took them YEARS to include us on their dealer website list, then only 3-4 MONTHS and several phone calls to spell our name right. We were one of their FIRST Arizona dealers.......
    These are only my experiences, yours may vary. TIMINATOR :frown:

  9. #9
    steelcomp
    You've got to remember that, depending on where you buy the heads, that a lot of companies buy bare heads and do a lot of machining themselves. They'll cut the decks, cut the seats and valve spring pockets, install the guides, etc. A lot of head mfgr's get a bad rap because of this. I worked for dart in 1990-1991 when Jim Becker was the shop foreman, and I guarantee that nothing that WE assembled went out of there looking like anything described here, (except maybe for the push rod clearancing. That was more a problem on BigChief heads with offset rockers, and we usually did that in house.) I don't know what has changed since Becker left, but it dosen't sound good. Not surprised, either. I bought a set of Canfield 310's (Best deal on the market, as far as I'm concerned) from Comp Products. They buy bare heads, as well, and do all the work I described above. The guides were all over the place, and I had to replace them, because they just ball broached them after installing them and assumed they were right. NOT! The rest of the head looked very nice, though. Good casting, nice ports, very well detailed. There aren't many independant shops that really know how to build a set of heads right. That's why guys like Alan Johnson don't advertise, and don't sell to the masses. You wanat the best heads money can buy? Bar none? Call them, but be ready to spend 10G. Most aluminum head mfgr's also expect that you as an engine builder know what you're doing, and that there is a certain amount of hand work required to make this hard core stuff work.

  10. #10
    Fiat48
    Fiat48,
    I guess you fared a lot better than me on the Dart heads.
    I bought a set when I originally assembled my engine in 2000 and they were some of the worst workmanship I'd ever seen.
    I bought the heads completely assembled. ( big mistake )
    First, after I got them bolted on the BRAND NEW ARIAS BLOCK I found that the pushrods were a long way from lining up.
    I ended up with a carbide burr doing some major hogging to make sufficient clearance for the pushrods to line up with the rockers. I must have used every four letter word I knew after buying what I thought was the best and found out how crude the machining was.
    So I ran them three seasons with an 8-71 blower.
    At the end of the third season I removed them for inspection and brought them to a local performance engine rebuilder for a freshen up.
    He calls me and tells me that most of the valves are bent and no good.
    I knew that they NEVER floated and there were absolutely no impact marks on the pistons.
    The dart boys who assembled them just dropped the valves into the holes that WERE NEVER GROUND and then proceded to install the springs.
    They never hit concentrically but bent to conform to the off center valve seats.
    I had checked the compression many times and it was actually real good so they must have bent to fit the hole right off.
    I'm real lucky that the valve head didn't break off and scrap the engine.
    I called Dart and got a lot of "well I just can't imagine how that could have happened"
    Besides the major problems the heads were never deburred after the machining and they never even blew the chips off before assembling. Didn't make much sense putting them into a plastic bag to ship them.
    To compare to it the Arias Century aluminum block was a machining work of art.
    Next time I'll try Brodix heads and assemble them myself.
    I went to Brodix a long time ago for much of the same reasons. I was surprised that the Dart block was as good as it was. But I have heard others say that their Dart blocks were also close on machine tolerance. Maybe cause the block is Dick Maskin's new baby.
    And I catch a lot of Hell from guys who do it...but I never buy assembled heads. I always pick my own components and do my own valve work. Then if something goes wrong all I have to do is find a mirror and point the blame.

Page 1 of 2 12 LastLast

Similar Threads

  1. Wanted-- 502, Merlin or dart BBC block
    By wsm9808 in forum Parts 4 Sale
    Replies: 1
    Last Post: 12-03-2006, 09:31 PM
  2. Dart or Merlin block??
    By 396_WAYS_TO_SPIT in forum Gear Heads
    Replies: 19
    Last Post: 11-18-2006, 02:57 PM
  3. 509 Bbc Merlin Ii Dart Eagle Msd Nx Pro 1
    By sdba069 in forum Parts 4 Sale
    Replies: 17
    Last Post: 09-28-2006, 06:26 AM
  4. Merlin or Dart heads?????
    By 396_WAYS_TO_SPIT in forum Gear Heads
    Replies: 97
    Last Post: 10-11-2004, 07:56 PM
  5. Dart or Merlin block
    By dreamsicle in forum Gear Heads
    Replies: 8
    Last Post: 01-30-2004, 05:15 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •