Offshoreonly.com - Cam and valvetrain longevity....??? low duration high lift...

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Quote:

Originally Posted by Full Force (Post 4483794)

yea, I hear ya, guess with a tad more HP figure if nothing else it would still go same easily... oh well...

took trans shift valve out tonight, gonna toss my valve from spare trans in tomorrow and see if I have reverse, that will determine what I do with engines...

I'm with ya, I mean, going slower, is never any fun. Problem with boats though, is there are tons of variables. Changing drives, fuel loads, air temps, tune up, all kinds of stuff can play into a 1mph change. You didn't have widebands on your old setup. Who knows, maybe they were borderline meltdown, but making some extra power . Its hard to say at this point.

Either way, ultimately, those 565's, ate chit, and and were tore up. You bought all new components, and while part of the goal was to go faster, the other part was to be reliable. Seems like this summer, you were out every weekend with the new builds. So at least you have that going for you. Nobody's going fast on the trailer sitting in storage with a broken engine.

Quote:

Originally Posted by MILD THUNDER (Post 4483790)

Even at 1.16HP per ci, 25 cubes might be worth, 30hp right off the bat.

I've harped on this since day one. Will have more power everywhere if heads support it, which at this level this equals a yes.

What I find really strange, MT has mentioned this too a few times, is FF's dyno #'s up top were like 600-800rpm later is only 8 addt'l hp. This is weird. Something is struggling. Airflow or fuel or mechanical.

As you know I am pretty much on board with all that when funds are there, very tempted to leave it be another year or two providing things compression test and leakdown good, then address ALL that at refresh time, unless I find a deal on headers if nothing else... I can do that with minimal effort, spend winter painting fairing, repairing indicator cables, putting my new gauges in and adding EGT, that alone is a decent amount of work and cost... it's always a battle lol

Quote:

Originally Posted by MILD THUNDER (Post 4483783)

If I were a betting man, I'd be willing to bet, if Tim had dyno'd his engines, with no accessories, some 2 1/8, or 2.25 dyno headers, with a decent collector setup, dumping into some big ole straight flex pipes, some tweaking on the dyno with carb spacers and stuff like that, he would have got much closer to his promised setup. Maybe not hit the target, but not 70hp away.

I'm going to stick with my gut feeling advice wise, and say that ,I feel his exhaust system is hurting him, he'd be better off with a dominator carb (got blasted for suggesting that during his build here), and a little more camshaft. Not a ton, but a little more.

If his boat was mine, and I was going to be making changes, I would be looking for a decently priced set of used headers, a different camshaft, taking the heads off, getting a nice valve job done with a back cut on the intake valves, ditching the MSD ready to run distributors, and figuring a way to get as much fresh air into that bilge as possible. I'd also be putting the scorpion rockers on ebay. JMO.

I'd forget about what everyone else is doing. If I followed what everyone else was doing with their 454's, they'd have been in the dumpster a long time ago.

Quote:

Originally Posted by SB (Post 4483799)

According to the widebands, the fuel mixture was pretty consistent on the dyno. The airflow turbines didn't seem to be showing anything weird. Both engines were showing the same story.

I'd like to say it was the camshaft. But, there certainly can be something else going on. Unfortunately, there just wasn't alot of time there on the dyno, to really play with things. Tim pretty much had 1 day to dyno 2 engines, and head back to ohio. The dyno numbers, seemed to pretty much show, what he was, or wasn't seeing, in the boats performance.

for sure not fuel or airflow, I could say maybe airflow in boat but certaintly not dyno, added another vent to bilge, also ran with hatch open 10" for lots of fresh air...

fuel was good on dyno and also boat, widebands and pressure gauges tell me that.

mechanical? not sure unleaa valvetrain is bad, but after 65 hours I think I would know... might be wrong... that's where leakdown will tell me also..

Quote:

Originally Posted by SB (Post 4483799)

Prochargers!!!!!!!!! Done!

You know what`s gonna suck even worse, you go thru the trouble and $$ of pulling motors, new exhaust, cams, go thru heads etc etc and go 1 mph faster.

WAP WAP WAAAAAAAA!!!!!

exactly, so I may just leave it, I may even just fix that trans next week, put the boat away running and do easy chit for once, restore my 85 Mustang GT I just bought back I had 20 years ago... easy winter haha

Quote:

Originally Posted by ICDEDPPL (Post 4483807)

You know what`s gonna suck even worse, you go thru the trouble and $$ of pulling motors, new exhaust, cams, go thru heads etc etc and go 1 mph faster.

WAP WAP WAAAAAAAA!!!!!

Blower motors.. you wanna go faster tomorrow just swap some pulleys, add a little jet ... boostane if you wanna get crazy or run some granny pulleys for everyday reliability.

http://www.birdsonggregory.com/wordp...ing_agency.jpg

Quote:

Originally Posted by SB (Post 4483799)

Motor is still trying to go but can't. Usually means there is a restriction. When you do a pull and it drops of fast it means the motor is done.