mercury 540 565 camshaft specs
 

Does anyone have the cam specs on the merc 540 and 565 engines?

How s this

Let me know if you can open that

I think he is looking for the new 565 motor

👍👍😊😊

Thanks for the reply, I should have specified though.... I meant the new EFI Engines.

Link Worked FWIW

Veloc410 is probably old as dirt like myself because that's the first thing that came to my mind as well. Bulldogs.

The reason I am inquiring is because with 2 engine packages so close in power I bet the in boat performance is quite different. The 540 is 522" 4" stroke and the 565 is 533" and 4.25" stroke. Curious to see if Mercury increased the duration considerably in the 565 to compliment the stroke. From my research it seems like there isn't much known about these newer EFI power packages yet. I'm 50/50 on my new builds going 4.25" stroke or building a large bore 4" stroke. I wasn't wanting to go tall deck so the 4" stroke is very appealing. Just curious as to how Merc views the difference in stroke and valve events.

I dont know the specs but mercruiserparts are showing the 520, 540, and 565 all use the same cam

Interesting... I noticed the 565 is relatively low compression at 8.7:1

Same cam the 525EFI uses. They use it in the 525, 520, 540, and 565 engines.

Must be the modern day equivalent of the 3/4 race cam!

LMAO, Nice!

Seems like the 565 would benefit from more duration given the longer stroke.

Have been on the fence about a 4.25" stroke or 4" for the new short blocks in the formula. Look at this article hot rod did using a lunati 231/239 hyd roller.

540 Big Block Chevy Engine - Godzilla Rat - Hot Rod Network

I wasn't sure if I could use my current 230/236 .598/.610 with this combo and achieve the power I desired. They used a similar SRP piston to what I was originally thinking... somewhere in the 10:1 neighborhood. I really don't need to spin the engines faster than 5200-5400 and it looks like they made power all the way to almost 6k with such a mild cam. Thoughts are appreciated.

The outfit I bought my shortbloicks from stated their 540 marine engine with dart pro 1 heads, 9:1 compression ,roller 237-243 duration at .050 lift and about .640 open put out 620 hp. That's what I'm using in my 572's . My heads are mildy ported and about 9.2 comp. If your running 10:1 compressing you can use longer duration. Comp cams makes an extreme energy 242-248 duration roller cam. You might be able to go a little longer. Those old flat tappet cam specs i posted earlier in thread fir bulldogs supposedly put out 500hp with 8.6 comp. And 088 gm unported heads. Some people say when they dynoed those engines they were putting out 540hp. I imagine with good heads 10:1 comp your going to hit 650 or more hp

kind of funny they refer to the 540 as a Godzilla rat..........I wonder what they would call a 903 Musi.........:lolhit:

Musigeddon

I know after I got the 572 short blocks, i kckes myself in the ass because i could have gotten even taller blocks. For a little more money

are you positive the 565 is only the 525 cam. I have a buddy with two 565s in a small cat and they sound pretty nasty compare to a 525.

Exact same Merc part number for all of them Genuine Mercury & Mercruiser parts. Racing & Hi Perf Sterndrive Engines

You are correct.

I just double checked by looking up each engine individually - 525EFI, 520, 540, and 565. I did this at Genuine Mercury & Mercruiser parts. Racing & Hi Perf Sterndrive Engines
They all have Mercruiser #400-8M0043065

IMO it's a great all around cam, sounds nasty but has great dock manners, making 640 reliable hp with it. Displacement will move peak power around.

After all that I forgot to list the specs:
525 EFI
298º/306º @ .004"
236º/244º @.050"
.610"/.632" Lift Valve
114º LSA

can you post some info on your engines like cu in,compression ratio and heads?

548"
dart 308 head
Callis cranks
eagle rods
je pistons
9.6:1

https://www.youtube.com/watch?v=u5JcAOsrT_M&feature=share