my new motor

[bajabob 718]

i am runnig dart pro 1 heads . dart single plane maniflod 1000holley carb . ss dry headers. so i prop my boat at 6000 and when i drive it i will run it up to 5500rpm will that be fine i dont want to to many rpm to hurt the drive??

[Rookie]

I believe the smaller wheel prop and spinning it to 6000 will be easier on the drive and engine. If the engine was properly balanced this should really be no issue.

What size Pro 1's did you get 310's or 325's?

[Geronimo36]

i am runnig dart pro 1 heads . dart single plane maniflod 1000holley carb . ss dry headers. so i prop my boat at 6000 and when i drive it i will run it up to 5500rpm will that be fine i dont want to to many rpm to hurt the drive??

Are you running a solid or hydraulic roller cam?

6K is pushing it for hydraulic roller setup...5800 is safer but then you're too close to peak torque in my opinion.

Also, on the dyno sheet your HP numbers were still climbing at 6100.... cam must have a lot of duration... I think you need a Crane 741 if you can find it...should be good for 625-650 hp at 5600 - 5800 rpms and peak torque around 4500-4800, that's just a guess though..

[bajabob 718]

Are you running a solid or hydraulic roller cam?

6K is pushing it for hydraulic roller setup...5800 is safer but then you're too close to peak torque in my opinion.

Also, on the dyno sheet your HP numbers were still climbing at 6100.... cam must have a lot of duration... I think you need a Crane 741 if you can find it...should be good for 625-650 hp at 5600 - 5800 rpms and peak torque around 4500-4800, that's just a guess though..

your set up is better than mine. . pro1 345 heads roller cam intake606 lift exhaust 617 lift duration .050 in 236 ex 244 lobe sep 112.0 ..my timming is 34degrees

[Trim'd Up]

Isn't your motor from Teague? I would be willing to bet you could make better numbers with a smaller head, along with much better throttle response, but I am no expert. That cam isn't big for a 540. It is smaller than the one Bob set me up with for my 548.

[Thunderstruck]

I agree with the others on the cam. Get a custom cam from Bob Madara. With AFR heads and his cams I made 595 hp with a 502 at 5500 rpm with 600 lb ft torque at 4200 rpm. My cam is <.6 lift on I and E with 228 and 232 duration at .05 or close to it.

Another customer of Bob's made 675 hp with 540's.

[Thunderstruck]

Oops, didnt see it but what is your compression. Need to up the compression to keep the cylinder temps up with aluminum heads. I am 9.6:1.

[Rookie]

Your 345's are to big killing air velocity and your torque. Your heads might be more of an issue than the cam. I also believe that is why you are spinning so many rpms to make your power.

[Geronimo36]

your set up is better than mine. . pro1 345 heads roller cam intake606 lift exhaust 617 lift duration .050 in 236 ex 244 lobe sep 112.0 ..my timming is 34degrees

Its from a friends 522" engine with Merlin Heads and Dominators.

Your 345's are to big killing air velocity and your torque. Your heads might be more of an issue than the cam. I also believe that is why you are spinning so many rpms to make your power.

I hear ya! After seeing his cam numbers something else is a miss cause that cam isn't too big at all! Matter of fact, with the right heads I think the cam could then become the limiting factor.

PS, I'd like to have his heads on my blower engines!

[bajabob 718]

you guys are rigth . the heads are to big. last summer i had problems with the springs i change them and the boat ran good . 1 was runnig 80 to 85mph depening on the weather i ran 5500 and all was good good pickup and top end was good

[Rookie]

PS, I'd like to have his heads on my blower engines!

I already thought you had good heads? or are you running Iron heads?

you guys are rigth . the heads are to big. last summer i had problems with the springs i change them and the boat ran good . 1 was runnig 80 to 85mph depening on the weather i ran 5500 and all was good good pickup and top end was good

I would just prop it to 6000 and then rev limit it @ 5800. I'm sure it still is going to FLY!

[bajabob 718]

I already thought you had good heads? or are you running Iron heads?



I would just prop it to 6000 and then rev limit it @ 5800. I'm sure it still is going to FLY!

that wt i think i am doing a have msd i put a 6000chip , my engine bluider balance my motor and fly wheel

[Geronimo36]

I already thought you had good heads? or are you running Iron heads?

Iron Grumpy's, low boost...

would be nice to run them puppies and even lower boost or f'it and more boost!

I would just prop it to 6000 and then rev limit it @ 5800. I'm sure it still is going to FLY!

Do you mean rev limit @ 6k?

[Rookie]

I just left the shop and these were laying on the bench. This is a Pro1 345-350cc that is getting ported and the floors welded up to get most flow with smallest area to increase velocity. I think these will be going on a 565.

[Rookie]

Iron Grumpy's, low boost...

would be nice to run them puppies and even lower boost or f'it and more boost!



Do you mean rev limit @ 6k?

F'it and more boost! If it's there you have to use it!

yeah 6K, i'm dumb sometimes.......

[MERPerformance]

I looked at this post last night and the dyno sheets didn't look right. I have a Stuska dyno and use Performance Trends data loging. The pull looks to me that the engine wasn't properly loaded until you were in the 5000 rpms. Look at the final averages, is the cam so bad that you only have about 500 rpms between peak torque and peak HP? You are only showing 80 + hp at 3000 rpms thats not right! If your dyno operator, doesn't have a automatic load control valve and he's trying to make a pull from the low to the high rpms, he should try loading the engine at 6000 rpms and pull the load down at a rate of 14-18 sec. He should be able to pull it down to 2500-2000 rpms. Also there is no correction factor, weather conditions. Does he have a Black Box Weather Station? Your A/F ratio at the lower rpms tells me that the engine is not loaded properly by the brake.
I agree with others that the heads are too large. You should be around a 320 runner, that 345 should be on a 572 or larger. The cam is unknown to me, I think your # should be alot better than that. I have done 540s with not so good heads and a solid cam and make 700 hp easy. Take a good set of heads done right, the right cam, built right from the start and go above that.

[bajabob 718]

MERPerformance can you look at this pull he run this one with 98jets in the carb . i beleave the dyno brake look like he trun a dail handle as he gave it throtle

[Geronimo36]

Looks like Mer hit the nail on the head with this one! Just goes to show what experience is for! That last sheet looks better to me with pk torque at 4800 but it would be nice to see one from 4k to 6K. Out of curiosity, why is he doing pulls all over the map and different loads?

All the dyno's I've seen they fully load at 4k rpms or so and pull to or just just past max HP. Then I have them do steady-state at various rpms.

Here's one my pulls and the dyno sheet at the end from Ritchie Zul's shop a few years ago;
.

[jeffswav]

I have blown my engine up many times. I have learned alot as I have went, mostly from the forums and guys like Bob RMbuilder. I run Large Oval Heads on a 489 so I am not that familiar with the Big Rec heads. It sounds to me you could probably sell or trade the heads you have for the smaller ones. Try to get your peak power at 5500 RPM. The boat will Idle and Plane off much better than a engine that builds its power at a place you will never use. I know you talked to Bob about a cam before you did the first build. I would have taken his advice whatever that was. Someone is leading you in the wrong direction and I hope this all works out for you. Good Luck!!

[bajabob 718]

ha jeff thanks i did tolk to bob we talk on phone a lot and he was a busy man he waS HOOKING ME UP WITH A CAM I DON T NO WT HAPPEN???? MT BUDDY THAT RACES A 38 FOOT FOUTIAN HOOK ME UP WITH THIS GUY . I AM AT THE PIONT THAT I JUST WANT TO GET OUT OF BOATING