540ci. Got questions
 

Ok. Been talking about this build forever, every time I get close to a start something else comes up in my life and this hits the back burner.
I think I'm ready to start slowly accumulating parts.

Want to build 540ci, na, pump gas 93 (I live in Australia and from what I understand your 93 is our 98. Correct if I'm wrong), hydraulic roller setup, 650-700hp max (want to use bravo Xr. It's a light 21' boat), efi and closed cooled, maximum reliability, no intention of forced induction.

Here is what I know I'm going to use so far (chime in if anyone has a reason why not to use the following):
- Dart big m sportsman 4.5 bore, 9.8 deck
- scat crank 4.25
- scat rods
- sr pistons
- dart pro 1 marine heads
- Holley efi and intake
- Dana exhaust manifolds

Here's the questions so far:
- What comp ratio should I be going for and what cc heads and piston shape to suit?
- cnc or standard marine heads?
- cam?
- rings? Brand, file fit or standard
- sump?
- dart offer block prep before shipping, is this worth while or will it need to have machine work done anyway?
- anyone used holleys self tune on boat? Is it reliable or would it be better off dyno tuned?
- valves and roller assembly (lifters, rockers, push rods etc.)?
- closed cooling kit?
- bearings?
- where does everyone get there billet pulleys?
- ignition?

I'm sure ill think of more later
Thanks for any input.

If I was going to start from scrach I would go with a tall deck block. 10.200 More room to expand later.

Haxbey speed has done a thread on the Holley Efi a lot of good info.

Start at 4.560 bore. Still plenty of room for a few overbores after that. 10.0 to 1 compression. 10cc small dome pistons.
AFR 315 cnc heads and a decent size hyd. roller will make 700 and still have good dock manners.

I have heard mixed things on afr's casting thickness. I know everyone says they flow great numbers from the box however I'd like this build to last a long time and darts pro1 heads look the better option in that respect. Not knocking afr, I really do think they are at the top of the tree with dart and brodix, just like some meat.

Want to stick with the 9.8 deck height due to height restrictions in the boat. It's going to be a tight fit under the hatch as it is, every inch will count. No intention of going bigger once built anyway, I'd rather build a whole new motor if that was the case. It's a ski race boat also and we have a 572ci capacity limit.

Where have you heard this about thin castings on the AFR's . I think someone is feeding you :bsflag:

Sounds like a good build Kurt. I'd look into the Callies Compstar stuff as well. Really good quality for the $. You can easily hit your hp goal with the Dart's or AFR.

I did a very similar 540 combo in the spring for a whitewater Jet boat. It was lower compression so it would live on 87-89 octane, and had a very mild hyd roller from Bob Madara to ensure the valve train has a long life, Gen VI block. This combo could easily hit the 700hp mark with a couple minor changes.

540, AFR 305's, Holley HP EFI, Dana exhaust. Dyno'd fully dressed with wet exhaust.

I just read a lot of forums through google searching on heads and that seemed to be the common complaint about afr? But then again it's not fact just opinion. I'd be happy to use afr, dart or whatever gives me the most reliability. Any reason not to use dart heads?

Nice motor, exactly what I'm thinking of, reliability and longtivety is key to me. My wife hates me working on the boat so I want to do it once and do it right. I'm not rich by any means but I'd rather take a little longer and spend a little extra if need be to do it right. I'd be happy with the dyno numbers your making with that motor. It's going in front of a bravo Xr so I figure 700hp was my max (bearing in mind light 21' boat).
What is that closed cooling system your using?

Those are nice numbers for a N/A marine 540, especially on a conservative setup. I love the fact it has 305 AFR heads on a 540, and a conservative cam, low compression, and still make good numbers. Not to mention dynoed in full marine trim.

No reason at all , they are good heads also . I must say that i have never heard a single bad thing about AFR's and plenty here use them with great results .

After reading your remark I did a search on Google to see what you are talking about, I searched "AFR heads thin casting" Out of 2 full pages I found several hits but when I opened the links they were NOT saying afr's were thin by any means, they were actually praising them for outperforming most other heads of equal port size.
I DID find found 2 different post on 2 different forums where someone was claiming the were cast in china and thin, 2 totally different forums BUT the same guy posting, "LUKE FROM SA", I think this guy is very seriously misguided, there is NOTHING wrong wiith afr heads and they are built very well, Smitty
HERE IS A LINK TO THIS BS:
http://forums.corvetteforum.com/c3-g...-afr-dart.html
"AFR will outflow a lot of other heads.
But.. Be aware that they are cast in China and finished machined in the USA. A BULLSHIIT LIE
They are are a thin head casting and not often seen on true race/high HP engines. EVEN WORSE BS LIE!
Very good bang for the buck.
I personaly believe that DART heads are a quality item, and made in the USA.
This would be my first choice.
I have had a few of each over the years.
I like the price of AFR but the long lasting quality of USA made DART heads.
You may notice that i'm from Australia.
I have done a lot of research BEFORE sending my $$ overseas.Tons of different heads out there for every budget.
Also cast and finished in many different countries. "
TOTAL BULLSHEET

Wow , what could possibly be the reason someone would post this kind of bullchit or worse yet , believe it . If you really want to know the truth go visit AFRs website or better yet give Bob Madara a call , he is an AFR dealer . Bob is also the best marine cam designer bar none . 585-654-8583

As stated nothing wrong with either head. Dart intakes flow better and AFR exhaust flow better, pick your poison. There is a recent thread here on OSO that someone just bought a new set of AFR's and he did have to have machine work. It was either resurface them cause they were not true or something about a core shift. It's manufacturing and whether we want to believe it or not there is always that 1or2 PPM that gets out the door. This is the only account I have ever read about AFR's. I would not hesitate to buy either I run Pro1's.

Edit: I have read about some Dart head bolt holes not lining up with the intake manifold and needed to be elongated or opened up. Later found out someone was selling blems... as new heads.

What cc piston did you use to get the 9:1 comp?
Lets say I ran same configuration as yours haxby but 9.5ish compression, what piston would give me this compression assuming I went the afr 305's?
Are any of the dressed head packages offered by manufacturers eg. Afr, dart, brodix any good or am I better off buying and assembling it all individually?

Hi Kurt, I'll get you all the part numbers when I'm back in the shop. For the best pricing and customer support you should contact RMbuilder on here, Bob Madara. He can spec and order your heads completely set up ready to go for your application. AFR's tolerances are excellent and you can just bolt 'em on and go. He can set you up with any of the other components that you need from this side of the world too.

The heat exchanger is from SeaKamp

Mr. Madara will assemble the proper heads for you with all the proper components and design you a cam to achieve your goals all at a price that will surprise you . He has always been more than happy to answer any and all questions you may have . Good luck on your project .

Hi Kurt, they were a flat top that poured about 3cc on the valve relief. The smallest dome on a shelf piston is usually 10 or 12cc. That'll put you 9.75 to 10ish depending on deck height, gasket, etc. If you plan on running low octane then I'd leave it around 9:1 to be safe. The half point probably isn't worth the risk for the very small amount of power it might be worth.

Thanks haxby
I definitely don't want to run anything other than pump gas. Like I said before the best we have here is premium 98, which is the same as your 93. I'll stick with a flat top piston
I had a look at the seakamp heat exchangers online. It says the kit is rated to 500cid, how does it go on the 540 with long periods at speed?
Thanks again for the input.

I highly recommend the AFR 305's with the CNC chambers, they do the bowls also. There is nothing better for the money. I do my own gasket match and port cleanup to save money. I had my engine machinist check the heads and they were dead on, chambers were within .1cc. Call Bob Madara before you buy anything.

If you're gonna run your 98 then there's no problem going with the small dome and 9.8-10:1 but, if you want to run your 93 then I'd stick with the 9:1. The heat exchanger works great, it'll hold 170 degrees no matter what. These guys will run an hour WOT when they're fully loaded heading in to camp. There are quite a few other good kits available; I'm sure you'd have some locally. I've gotten some really nice stainless stuff from NZ that gets used on the Marathon race boats.

Ok. What's the difference between the dart big m sportsman and normal big m? I know sportsman has ductile main caps and big m has billet mains. Is this the only difference? Which should I be going for on this build? Are these 2 piece rear mains or 1 piece?
Also, are the je piston rings any good or should I be going total seal? If so what type ie. gapless, standard, file fit???