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Discussion Starter #1
Hello,

I plan to build a 331 cid engine with around 8:5 low C/R.

I need to locate a R302 block, Where would i find one.

Most important how much one of these blocks run?
I got quoted 10,000 on a fully built up 331, but i think i can do better then that.

thanks.:)
 

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Many places offer them. I got mine form Kieth Craft Racing. BB&T Racing sells them too. How much power you wanna make? If you're just talking short block, you can get a forged short block much cheaper than 10,000. I'd guess 5,000-6,000 with forged Eagle or Scat crank/rods.
 

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i would go with the dart block, they have 4 bolt mains all the way through. the a4 and r blocks only have the middle mains 4 bolt, the end ones are 2.

if your not going crazy with it, the r or a4 block would be good enough
 

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Maybe 4 bolts on all mains, but the big ones are 7/16" opposed to 1/2" on the R302 block.
 

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95gt/98cobra clone said:
i would go with the dart block, they have 4 bolt mains all the way through. the a4 and r blocks only have the middle mains 4 bolt, the end ones are 2.

if your not going crazy with it, the r or a4 block would be good enough
What is your definition of crazy? :idunno: Cars have made 1700+ hp with R302's :lol:
 

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and i have seen stock blocks take 850hp, MY POINT IS....IF YOUR GONNA DO IT, DO IT RIGHT THE FIRST TIME. dart blocks come fully machined. i can get them for 1900 to my door. you will spend upwards of 1500-2300 just getting the r and a4 blocks to where the dart block comes from the warehouse. by the time you get done with a r or a4 block you will have over 3500 tied up in it. when you could just buy a dart block for 1900 and be ready for assembly.

MY DEFINITION OF "CRAZY" IS..........HAVING 3500+ TIED UP IN AN A4 OR R BLOCK, WHEN YOU CAN BUY A DART BLOCK FOR 1/2 THAT. AND BE READY FOR ASSEMBLY. PLUS HAVE THE INSURANCE OF 4 BOLT MAINS ALL THE WAY THROUGH.:eek: :eek: :joy: :joy:
 

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No need to yell fella, don't get your panties wadded up :p

If those were your points, then that's fine. But they weren't in your original post, you were bringing up a strength issue, which is usually not gonna be an issue at all with either an A4 or a R302.

BTW, who is charging 2300 to prep a R302 block? :eek:
 

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dart blocks come fully machined

That is strange, When I bought my R block they had a Dart sitting right next to it. They said by the time you take machining into account on BOTH blocks, the R302 is still cheaper. They way they made it sound, the DART requires a decent amount of machining as well.


I spent nowhere near 2k getting my block machined. It was around 700 dollars.
 

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You can also get R302 blocks at some of the Ford dealerships (thats where I got mine), so you might want to check at your dealership that way you save some money on shipping.

My R302 w/ 8.2 inch deck was 1600 plus about another 700 for machine work which included balancing, a .080 overbore, plus pluging the holes on the deck, so I guess I have about 2300 total into it. Rotax makes a good point about the 1/2" mains on the R302 block.....those are nice.

Ford doesnt make the A4 blocks anymore, as far as I know, so you would have to find a used one somewhere if you decide to go with that block.

The one good thing about the Dart block is you can get it in a 4.125 bore standard which would really allow you to unshroud the valves and give you somemore cubic inches, but at the same time you would need some custom pistons which would cost more.

Either way you choose it is ridiculous to think you are going to just buy a Dart block and just start slapping you motor together. The Dart block will require some machine work as well just like a stock factory block or R302 block would.........just not as much, and you are going to need to check everything before you assemble.

In the end either block will handle 1000hp easily, so whichever block you can get the best deal on, including machine work, should work flawlessly for you. Good luck.
 

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Well, I have no experience with either, but I'll just share what I was told when looking at some 351 blocks.

I was talking to Pete Kotzur down in San Antonio about the W351 blocks, vs. the Dart Blocks. All the dart block needed if I remember was to be CHECKED, finish bore, and "square deck" I believe it was. He said everything else is good to go, but worth checking of course before assembly to make sure. But with machining costs, the DART was the cheaper way to go, and more worthwhile IMO.
 

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Exactly what John Morgan said...

There's no way in hell that I would buy a DART block and just simply put it together. It won't happen that way. I talked to Keith Craft before I ended up buying my R302 and he mentioned that the DART blocks do indeed come machined more than a R302 block, but it still requires line honing and some other attention to detail. I was quoted $2400-$2500 for a DART block AFTER the additional machine work was finished. I paid $2,070 for my R302 and that was fully machined.

The point here is that either block, DART, R302 or a USED A4 will handle the power that you are after. Even the 4 bolt issue all the way like the DART block has is a nice feature but come on, really do you think that any of us corralers will ever break a A4 or R302 block. These blocks have been beat on for years and guys don't have breakage because they don't have 4 bolt all the way thru.

I am in no way bashing the DART block, but it is not the end for the Motorsport blocks.
 

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I agree completely with John Morgan...
The thread-starter stated he wanted a 331... the Dart and the R blocks will both require the same machine work. I have spoken in depth with Keith Craft about this and it'll be about $6k out the door for either block you choose. $10k for a built 331? Ha! Gimme the $10k and I'll have one ready for you! ;)
 

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i didnt mean you could just throw a dart block together, you always check everything no matter what. i looked into both blocks, and every single person that i know with a a4 or r block said that they had to do the same amount of machine work on the their blocks as the stock block, in one case a lot more. it had cost them upwards of $1100 in machine work for those blocks. (i a talking fully race prepped (no corners cut) i know 2 people that recently got dart blocks and all they needed was aline honing, boring and torque plate honing. from my experiance i would say that they are both going to handle whatever most people can dish out.........but "in my opinion" the dart requires less machine work and is a better built block.

so to answer the thread starters question: its pretty much whichever one you can find the cheapest...thats the one i would go with.
 

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95gt/98cobra clone said:
and i have seen stock blocks take 850hp, MY POINT IS....IF YOUR GONNA DO IT, DO IT RIGHT THE FIRST TIME. dart blocks come fully machined. i can get them for 1900 to my door. you will spend upwards of 1500-2300 just getting the r and a4 blocks to where the dart block comes from the warehouse. by the time you get done with a r or a4 block you will have over 3500 tied up in it. when you could just buy a dart block for 1900 and be ready for assembly.

MY DEFINITION OF "CRAZY" IS..........HAVING 3500+ TIED UP IN AN A4 OR R BLOCK, WHEN YOU CAN BUY A DART BLOCK FOR 1/2 THAT. AND BE READY FOR ASSEMBLY. PLUS HAVE THE INSURANCE OF 4 BOLT MAINS ALL THE WAY THROUGH.:eek: :eek: :joy: :joy:
Where can I get one for 1900. to my door
 

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Get the dark block at the end you will have more money in your pocket.
 

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Very little machine work on my Dart block!! Sure the deck is .020 higher and bore needed honeing but thats all.. Everything else was checked though...
No line boreing required...Alittle grinding to fit std H bones and braket / spring that holds then down...Thats all...
 

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A4 blocks do not come in two different deck heights, but the Darts do. There are FMS offerings at other deck heights but they are different part numbers.

A4 and R302 blocks if never been touched of course will REQUIRE machine work, they do not even come in a standard bore size. They will REQUIRE more machine work than the Dart offerings. The Dart comes machined but usually requires SOME machine work.

A4 blocks have not been made in years, so chances of finding one that has never been touched is pretty slim.

Once you do the machine work on either a new R302 or new Dart, chances are you will have the same amount of money or close to it in either offering. Although the Dart Sportsman is a little cheaper from the get go, so might come out a little cheaper at the end of the day.

Can anyone show any proof of a A4 block breaking from too much power? It would probably be the weakest out of the three options and I personally have never seen one break from too much power. I have seen tons of them in the 1400hp power ranges and no breakages. I'd bet someone not wanting to spend $10k on a motor, is not looking to ever get in that power range anyway, but again I'd like to see where their "weakness" has ever been a problem.

You can try piecing a motor together yourself in hopes of saving money, but chances are it will end up costing more than some of the built ones out there. I have seen built Dart shortblocks new in the $4-5k range, I think AD Performance sells them for around $4300 just as an example.

How and why would you ever have $3500+ tied up into a R302 or A4 block? I own a A4 block in my LX, I think I paid $1700 new for it and then $400-500 in machine work to have it ready to build. I bought this before there was a Dart block and before there was a R302. Matter of fact it was back when A4 blocks were flat out hard to come by but your only real option besides maybe a Boss block.

This $10k motor offering, what all did it include? I have every bit of $15k in my 347, you would be surprised how quickly somethings end up adding to. For instance as I pointed out I have $2200 in my block, then $1800 in lifters, $1800 in rods, $1500 or so in the crank, $1000 in the pistons, $300 in the cam, probably $500 in the balancings, $1000 in balancer/flywheel/flexplate ... look I am around $10k already and I have not counted all the ARP bolts/studs, oilpan, oil pickup, oil pump, the heads(big $$$ here), the pushrods, the rockers and god only knows what else I am leaving off. But I have billet internals and all the other fun high hp stuff that is supposed to last, it could be done for cheaper with cheaper parts.

Personally if I was doing a motor, I'd do a Dart Sportsman block because it lets you run regular lifters(although this is minor since the Iron Eagle can use them with som mods) and a regular oil pan(which I would want on a street car). Plus it is the cheapest new option and still so strong that you need not worry about ever breaking it. I'd go with whatever the affordable steel crank/rod combo is today, probably something made by Eagle or one of those companies. What I am describing I bet is what AD Performance is selling and probably what other companies in the same price range are selling.
 

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Go with Dart because of the better cooling passages. Considering both blocks are strong enough to take just about anything you plan to throw at it and close to the same price.

Oh also I have heard that the Dart is a bit cheaper to machine but how much I'm not really sure.

I guess what I'm trying to say is if you find a good deal on either block you should jump on it. Just as you've been told by others you should probably expect a couple of hundred extra dollars for machine work on the R302.
 

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I would not let the cooling passages be a worry, price I would let be the worry though. I have a buddy down here in hot, humid Texas who has a 331 R302 motor in his Cobra and it has been his only car for well over a year so sees a lot of daily driving. He has no cooling issues at all with that car and it does not have some "fancy dancy" cooling system such as a big ass fan and so on.
 
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