My Crane Cam
 

Don't have the engine build to my BBC's but I have the Dyno sheet and it's noted that I have Crane cams (hydraulic roller special) I have less than 20 hours on these 575's that were built in 1996
My question is looking at the Cam sheet what can I determine about these Cams?.......are they for a mild build?........also, was trying to find what compression I have to determine best fuel...right
now I running AV fuel...........I'll in close Dyno sheet and Cam sheet........maybe someone with knowledge can give a general impression of my setup.
https://cimg4.ibsrv.net/gimg/www.off...0a5df415d3.jpg
https://cimg6.ibsrv.net/gimg/www.off...166dba1c92.jpg

That cam is still used alot typically in 540 or larger marine engines. Lots of roots supercharged marine engines too.

My engines are running a little lean on AV fuel ....I didn't have (or get) the correct compression ratio from the engine builder so my main concern is proper octane fuel to use.
probably an easy solution to this, but how would I determine proper fuel for my engines?

I don't see a compression ratio stated nor a octane of fuel used, on the dyno test.

There is a specific gravity for the fuel used, but don't ever try to guess the octane from that.

Maybe do a search to see if anyone has a Whistler in your area you could pay to test your engine (s) ?
https://store.katechengines.com/whis...ster-p174.aspx

Thanks SB!.........Reached out to Flagship Marine today (they built & dynoed the engines) the engines were built in 1996 & no mechanic there now was there back then to remember.
He did tell me that all their engines whether 540's or 575's run on unleaded 89 octane with 9.6:1 to 8.1:1 compression ratio's if this is the case I've been spending big $$ on AV fuel I
don't need and maybe burning the exhaust valves!........

Talked to the builders son @ FlagShip Marine about my 575's ...He's sure the compression is 9 .1 .........and ignition timing is 8 to 10 bottom ......and 28 to 30 on the top!
He assured me all their marine engines run on 89 octane........since I've owned the boat I've been running AV fuel which caused the engines to run lean....AV fuel is too
expensive and may have been damaging my exhaust valves............any recommendations for which pump gas?.........Sunoco 94???......Shell v-power???