540 build cam selection with gil exhaust
 

Im building a 540 with afr 265 heads and was needing advice as to how far i can go with cam selection im looking at 239int, 247ext around 650 lift will gil exhaust be alright with that thanks

Heads seem kinda small for a 540.

Are the Gill's Dry ?

Stay on a 112 or 114 Lsa and you'll be fine. I like the heads but any particular reason on that CI. With that cam duration and runner volume on a 540 I'd think you'll make peak hp close to 5,300 or so depending in induction. Lot of 540 builds out there with 310-320 runners with a little more duration.

What's it going in?

Those are the heads i got it was going to be 502 but got into it and decided to rebuild it and may as well get the cubes 265 afr is small but flow very well im hoping it will work good, no the gils are stock hp500 short style and its a baja outlaw 25 thanks for the help, i also have a cam laying around thats 228int, 234ext, .600 .570 on 112 but was thinking it was too small it also has factory dart intake and carb

Personally I think you'll have a nice build. Won't be lacking torque that's for sure. I've used those heads ported on a marine build and they were awesome. Boat pulled extremely hard.

PS my vote would be first choice on cam. Heads will do well with it. Should be more builds like this. Simple and very effective. Cheers!!!

Im hoping it will make 625ish hp and a bunch of tq do you think the gils will be ok with the first cam choice

What power did you have before? What drive is behind it? I have zero tech value to add, in just curious about other's projects.

Its has a bravo 1 with hydraulic steering it was originally an hp500 carb

Just built a 548 with a little smaller cam and steel heads made 621 hp and 675 lbs. torque. Should be no problem.

do you have a copy of the cam card by chance. Personally I'd use it and not look back. How I got away with cams used years ago without reversion is beyond me. One bad choice but was during the marine learning builds nearly 30 yrs ago and cam was on a 108.

You can always swap out to dry pipes and cheer some blow boaters up. Hah. You'll be fine. Is that a custom grind or Howard's by chance? Specs don't sound familiar. Just curious.....

Its a comp custom grind i called and they said this 239,247 .643, .653 on 112 the nice part is the price is 337.00 cause its a common blank, ive also been recommended the crane 168741 236,244 .610, .632 on 112, 540 tahoe what type of steel heads and what compression im looking at 10:1 or 9.6:1

What type of steel head, compression, and what rpm was the peaks thanks

A 265 head, 228/234 cam for a 540? Holy $hit.
You guys are nuts, but I guess if it just laying around why not right.(sarcasm) While you`re at it maybe you have a carb laying around ,maybe from like an old lawnmower or something. It`ll be perfect for this build.:D

The heads are 088 with slight port and bowl work, 10.5:1
Cam specs are 631 both sides and duration is 252 on both sides as well on a 113
http://i393.photobucket.com/albums/p...psaynqua8k.jpg

Thats nice power with the 088, i may be looking close to that i have a bit less compression the cam will be smaller but the afr 265 flow way better than a stock 088 especially on exhaust side and low lift areas but yours are cleaned up some thanks alotfor the help

$337.00 for a Comp is typically a cast iron core. Be careful and always question and then follow up and make sure their answers are correct.

Does anyone have any ideas on hp and torque or maybe a better cam selection to spin it 5500-5800

Those 265's will fall off early IMO. Id expect to see 5200-5300 unless you let it breath better. If that's the head you must use, match the parts. Trying to over cam a smaller head will disappoint you.

Do you think 625hp is doable and a bunch of torque that should get thing moving and probably stick with the 239/247 cam or smaller?

Those heads are way to little. I ran them on a 439, and they were an awesome head. On a 540, it would be one of the last heads I would pick, and no way you're going to make power to 5800. Those heads are hard to find used and you could sell them at a premium due to that. Why not sell them and get the proper head? 265 for a 540 IS NOT the correct head.

If monster torque is so important, why not just throw a Caterpillar diesel in your boat?

Thanks for the advice do you think bigger afr oval or the 325cc square

They're quite a few lengthy threads here about optimal heads / carbs for a 540. Whether or not to even use AFR is likely to be a lengthy discussion.

The 290 and 300 ovals, 305 and 315 rectangles are all great heads. I'm not an engine builder, so I'm not suggesting anything other than the 265 is just a little head, and it was designed for a 454. A 540 is WAY bigger than a 454. Say it cost you an extra $900 or less to do it right, then I would do it the right way. IMO you are leaving a lot of power on the table with that tiny head. If I was building my 509's from scratch I would be running either the 290 or 300 ovals.

Wow I agree with endevour89 100%
:noevil:

I got a set of iron 502 heads i'll trade you for them...hell I tried.

I agree with the above. 265 , with a 2.19 valve, is gonna limit power. You'll make some big low rpm torque, and lack upper end power. It will allow you to run a really tall pitch prop, add some extra stress on your outdrive, and probably accelerate like crap, since it will be like running a 3.08 rear end, vs a 4.10 rear end. Theres a reason nobodys really running diesels in FAST offshore boats.

Thanks for the help guys i think im gonna swap them for 300 ovals or 305 squares any good cam ideas for 5600-5800

Is there any reason youre partial to the AFR heads? What about brodix, dart, Trick Flow , Engine Quest, Promaxx, profiler, RHS , etc ?

Im not 100% on them afr they just normally apples to apples outflow the others but brodix has a newer rr bb xtra 3 Oval but i need to call them monday to get more info

Check out the EQ heads. Flow really well out of the box. They aren't very expensive either. I have the 320s. Still assembling and haven't dynoed. Joe also has them on his motors.

Ive seen them they are supposed to be dam good i want to stick aluminum and preferably around 290-310 cc runner its only spinning 5600ish

If you go with them assembled, I might suggest taking them apart, having the valve guides checked, and replacing the cheap entry level valve springs they come with. If you wanna go a little further, a sintered powder metal exhaust valve seat to replace the ductile iron seats they come with. The sintered powder metal seat is what GM used in the stock merc heads, and engine quest uses as well. If in fact, you are looking for durability, and going the distance.

No matter what head, buy bare and have them built to needs I will never buy assembled heads again... ever.

X2. I would never trust what components are actually assembled with let alone some of the shotty valve job work. I'm sure you've seen the ol man on YouTube covering all the different heads that get purchased assembled. Regardless what brand. It's to bad really. I hope you let AFR have a piece of your mind with your ordeal. I've had my problems with dart castings also but they quickly resolved with replacements. It's not just performance it's everything nowadays.

I got a recommendtion from jones cam designs a 242/245 @50 with 640ish lift on a 114lsa with afr 290 how do you guys feel about that

a guy near me is trying to sell a 496 he had built. pro comp head dropped a valve at idle. only killed 1 sleeve, I head, and 1 piston. so he only wants 3k. this is a current day example of Chinese valves.

Yes i could see that i have not heard alot of good about procomp heads castings or parts