big ci bottom end
 

Wanting to build/buy a 540+ cube short block, after reading Audio's thread on the perfect 540 i'm a little confused. What i'm looking for is a N/A motor with super mid range torque, dependability, and the ability to use my rect. port iv heads for now, until i get enough money to buy some good alum. ones.
After reading that thread though, i'm not sure wether to go with a tall deck and longer rods, or a short deck with bigger bore and be able to utilize my heads, intake, distributor, etc. I don't want to cheap out on the bottom end, I really would not want to look at it again for 300- 500 hrs:rolleyes: I've beens seeing the inside of engines much too much lately.
So for a N/A motor whats the best route for the end of the day? It's mid april already, thought about picking up a dart/merlin block, and a complete rotating assembly from Lunati or callies and putting it together myself, but the problem then is i've got to get flywheel, balancer, oil pump, cam, lifters, etc. alll seperate. Wouldn't it be better to pick up a complete --pan to deck short block? I've been told that my cast iron rect. port heads will work on the gen vi block, would like to just transfer all from my 461's over to something actually new.
Can anyone tell me the pro's and cons of the stroke vs bore war?:confused:

Look under Big Chevy on ebay motors, there a a few good kits for sale there I saw this morning. I have dealt with Dynoflo and he was great to deal with. I have an eagle 4340 crank in my motor and ran it all last year no problems,looked brand new when apart this winter, on a 540 blower motor. His complete ready to assemble balanced kit for around four thousand with a Dart Big M block is a deal. If I made any changes you might go with a set of billet Oliver or Crower rods, and I think this would be a great combo. I have billet Lunati in mine.

JUst go with 250 long rods and short deck so you can use your stuff this is a good combo of motor ,I'll help you with the parts or the deal on e-bay sounds o.k. if the rods and pistons are a good brand ,,,advise and I'll help if needed

Hey Del sol,
Give Lenny at Millennyum Marine a call. He is doing exactly what you are talking about in a friends 31 Scarab. The guy is on a budget and they HAVE to be reliable. I know what he is spending and the price is right.
His number is 586 468-7361.
They are hoping for speeds of 83-84 out of the 31.

Thanx Chuck, I just got off the phone with him, he's going to give me a price. Did you say that you had some issues with your eagle crank? I told him I'd rather stay away from them. Now I've got to come up with 2 gen 6 502 blocks. Unless I go 2 new darts:(

Isn't the dart factory near you/close. Wonder if you can buy direct, or if there is ever any scratch and dent blocks??

We did have some issues with the first three cranks. Nothing major as long as the person building the motor caught it. It just seems like they don't have that good of a QC dept. for thier machining. For the price and in a N/A motor I don't think there is any problems with them. I know in the past I said I wouldn't use one again but I've had the motor apart twice since it's been together (lifter problems) and it was fine. Just as long as the machine work is checked. I haven't heard anything about the ones he's putting together now .
I thought you had some 502's in your boat now ? Can't you use those ?

No my 10 hr. 454 gen 4 rebuilds look like they've got closer to 250 hrs on them. So instead of putting the wedges in the heads to pump them up I figured i'll just buil up some 540's and use my rect. heads, I need the extra torque anyway. so now I'll have 4 454's for sale here soon, I'm going to run them until these 540's are built then just pull and swap parts. I'm getting real good at pulling these motors:rolleyes:

Bobby--- whats the best/ cheapest way to get into 502 blocks, as i'll need the balancer, flywheel, pan, etc.

3 eagles in a row--- doesn't sound so hot,

what about the scat cranks, it seems there's alot of them being advertised also.
from what i've been reading this morning the 4.25 stroke crank is the same price as the 4.50, why would i got to that right away, even the block is the same---that is if i end up buying a new block:(
How much diff is there between the 509 and the 540 in the end?? I'm looking at it and thinking i could use my present steel cranks out of the 454's into a 502 block and get into a pretty reasonable 509, as long as i can find 2 gen 4 502 blocks!
500-550 hp should be possible? plus the increased torque i would think,

Just remember there is no substitute for cubic inches !
I think the Scat crank is along the lines of the Eagle stuff. Just remember, engine parts are like alcohol the more you pay the better the stuff.
I think 500-550 would be a little much for the 454's.
I don't know is Lenny mentioned it but he has some rebuilt 525's for sale. They have zero hours on them. But for that kind of money I would rather build the 540's.
Contact Rod at Performance Marine, I don't have his number but I'm sure someone on this board does. He might have some blocks. He could also build something for you, he is another very credible engine builder, just not local like Lenny.

500-550 would be the 509's --4.5 bore * 4.00 stroke,, I was running 475 with the 454's already. So if i put in a hyd. roller cam into the 509 i'm guessing should be up there close to 525 +/-.

I'm just going on the fact that Lenny's girlfriends' boat has some 502's with solid roller cams, ported heads, dart intakes,dominators and cmi headers and we are guessing 525-550 out of those , her 31 Scarab runs 78-79. I think if you do it with 454's you will need better heads more cam and you will be spinning it higher than it should for reliability.

no problem with a good pocket port job on the heads and good cam it will do this ,8.8 to1 comp,,to 9 to 1 ,,, it will be a fast beast 5800 is about the limit with a hyd roller the cam is the limiting factor not ,not the bottom end :D :D

Listen to Bobby he does this stuff for a living:)

My preference is to go bigger, your boat is a pretty heavy boat so the more torque the better.

OK -- maybe i've been looking at tooo many different combos, but i just ran across a 524--- 4.5 stroke +4.31 bore ( 454 .060 over)

will this even fit into a stock gen 4 block?? the nice thing about this , would be when i'm ready to buy the good block and heads i could make a 604 !!:eek:

It all comes down to trying to do it reasonable but still be able to buy the right stuff a little at a time.:D

Hi,
Not that I am a Pro, but I have been on his board for a while.I have been told that 4.250 stroke with 6.385 rods is the best to run in a standard deck block.If you want to spend the $ for a new block then go tall deck and run a 4.5 stroke and 6.535 rods with a 4.5 bore that will get you 572.cu.but a tall deck needs intake spacers and a longer dist.

Rob

A Crane 741 cam in a 509 made 563hp with an Air Gap dual plane intake and cast iron World Products heads (NON ported) on Tyler Crockets dyno. Bobby Daniels would be a good one to contact for the parts and any help. I have bought stuff from him and he has very good pricing on his stuff :)

go with a 4.500 bore (or 4.470 stock 502 bore). The BBC likes the big bore cause it unshrouds the valves and gives more unrestricted flow. If you want more stroke, fine, but do it with a 4.5" bore. 4.25 stroke will work in a stock block but any more and you're notching and grinding and cussing.

----------------------------------------------
It will fit 99.9% of time ,,I've only had one block not do it !
There are tons of combo's your right the stroke may be to much
on this one a 4.25 plus 250 long rod and that bore makes a killer motor 496 ,and it will live forever and don't have to grind much on block
Kaama's right the 509 is a great combo also
Just depends on your funds ??????:D :D

Re: big ci bottom end
 

we've always had the Scat available

Re: big ci bottom end
 

if your going to build a stroker in the marine world you need a good strong bottom end. caliles, luntina and crower all have good fully counter weighted cranks and good rod to choose from .you should be adle to make in between 580hp. to 600hp with a 509 and a hyd roller pocket ported heads on pump gas with reliability .are avrg. 509 dynos above 600hp. a 540 should make at least 635hp to 650hp and still be reliabill. call me if you have questions mon after 12.00 at CMS Racing engines 410-335-2226 P4-5 CMS.

Re: big ci bottom end
 

Scat is also made in CHINA (like eagle) but is even a LOWER grade,i would avoid in a endurance motor. Stock 502 block bored from 4.470 to 4.500 w/ a 4.250 stroke would be 540 and have EXCELLENT bore to stroke ratio. The Callies dragon slayer crank is the cheapest crank(around 750$) made in usa. Competition products in wisconsin sells them,ask for roger hurst,tell him smitty from michigan told you to call. He often has killer deals on unasembled short block packages with different levels of quality. Last year they had about a dozen 496 shortblocks(using 454 block w/4.250 cranks) for sale assembled new(except block was "seasoned") for 3000$,a killer deal,Smitty

Re: big ci bottom end
 

wow I think i forgot about this thread -- it's a year and a half old.

As it turned out I built 588's, and bought most everything from Callies direct, except for the AFR heads. Everything should have been great except for the questionable character that assembled it. I don't think he had ever put together a BBC marine motor, although he claims yes -- i was referred to him by the supplier.

As it turns out they put out 700 + hp but haven't been totally reliable-- they are out now to look at fluctuating oil pressure issues. It's a good thing I built a set of spares for just this reason :cool: