A modded motor with stock pistons and stock rods will last @ 4980 rpms? Went run it yesterday for a little while opened her up and this was the results, and No Im not blowing out.


Thanks
Jamie B

No matter what you got in it they Will not last at those rpm's !!

Yea I know, and the motor is pinned on the bottom hole. I might try swapping some pulleys around any advise on what size to start with. I dont plan on running it hard that often when i seen that, wish i would have had a GPS with me .

Thanks
Jamie B

Trim down. If you're spinning that high your entire prop is out of the water.

If your prop is a little worn it is not new. U can't change pulleys on a prodrive anyway.

Til it goes "Clunk"

Won't last long If you want it to last,Leave it stock!

Better gear it & pitch it, before ya blow it!!!!!

Taking it easy with out a rev that is impossible

Thanks for yalls opinions, the reason this was posted was to get different opinions on what different people would have to say, this motor was the first of what we wanted to try different with the head work, this motor suprised the hell out of me on its first run and seems it is getting stronger every time we run it. This motor was rebuilt due to having 39% leakage on a leakdown test performed at 964 hrs with mods on motor turning 4700 to 4800 rpms. We are still tinkering with different recipes on the head work but this seems to be the strongest most consevative we have came up with as of yet. All i can say is wait till the 31 block we are working on is finished with the mahine work and rebuild complete, it will be and animal!


Thanks for the opinions, keep them rolling
OH and there will be no taking it easy with this motor!

Just remmeber HOT motors only last a little while. John force's Top fuel funny car prolly gets rebuilt after each run. Good luck with your build man!

Yes sir you are correct, they dont last long being dogged out every time you put it in the water, I think with the current setup I (should) be able to run it at about 46 to 4700 pretty long, not saying i will get another 1000 hrs out of this set up but it will be fun to lay into it every once in a while.

my last one crapped out and never ran over 4400,ever.

if it happens tommorow then it was fun. I just got back from running it today with the 12x11 wheel it dropped RPMs down to 4760, still dont know speed yet due to only GPS I have is a stationary HDS7 mounted in dual rig. Seemed a little sluggish out the hole with 12x11, but its seems to really flatten out the boat on top end, so i need to get a gps on both props to give any sure speeds on different pitch props.

Whatever you do it has been done before


Maybe so, maybe not

If you have the option- play with gears and props. A higher gear ratio with more aggressive prop is the best combo I have found.

I was always told stock rods ~4600 is about where you want to stay below. Guess your 900 hours disputs that.

Which by the way this GPS he is referring too beached us at 0530 in the morning and we spent 45min. trying to unbeach it, did i mention that a dual GTR rig is heavy as fork[/quote]


No this is a brand new one to Play with

I wonder if thid one shows downed trees in the middle of the Bayou, tranaus, whatever ya'll call it, since that is the reason we ended up on the bank in the first place, that co9uld have been a bad morning for 3 of us for sure!

Yep, that had the potential to take a turn for the worse real quick. I figured hit it or beach it, so I picked beach it.