Is it summer yet ??

[Dragonalain]

The hull is probably custom made in the late 70s it had gee craft on the side but can’t find anything online about it. I Did a ton of modifications this winter to turn it into what it is now. It has a Berkeley 12jc pump in it that I rebuild with a A3 S.s impeller. One nice thing about this hull/ pump design i think is the engine is probably almost two feet from the back and there’s a 10 inch trim tab the full width of the boat behind that. Yep

I Went a little over kill on the engine but I have been wanting to build a big engine for a while now. It Started life as a 460 Bbf that was HEAVY. I bought every alum part I can buy for it minus a block.

The build list for the engine is

Eagle 557 stroker with H beam rods. 9.5-1
Alum weiand 8012 intake
Alum 280 AFR heads
Alum water pump
Alum Comp cams rockers
Comp cams cam
Holley sniper good for 850 NA and 1250hp on boost
Holley timing control
Holley snipper distributer
Holley sniper valve covers
Stud girdles

Boat has two tanks that hold 500L so even with a 557 I should have decent range if I want.

 

[pfi572]

So the bowl bolts for the pump go through the transom? Old school ?
I would have moved the pump back and put short drive shaft to keep motor ahead if you wanted more weight ahead .
Working on the pump sucks unless you have a pump zipper on the bowl and then it’s not a big deal with it bolted to transom .
Be interesting to see what the 557 will turn for RPM . Anything over 5000 rpm it’s making some good hp and TQ

 

[Dragonalain]

So the bowl bolts for the pump go through the transom? Old school ?
I would have moved the pump back and put short drive shaft to keep motor ahead if you wanted more weight ahead .
Working on the pump sucks unless you have a pump zipper on the bowl and then it’s not a big deal with it bolted to transom .
Be interesting to see what the 557 will turn for RPM . Anything over 5000 rpm it’s making some good hp and TQ

Similar engine builds seem to make around 750 hp. however the cam I got is not going to get it close to the hp that it could make. I’m shooting for 550 ish hp and a ton of torque. This boat won’t need that extra 200 Hp as I have no intention of doing 90mph on the water. The 550 will push the boat around just fine for what I want. The extra 200hp I’m leaving in the table takes fuel to make.

Here’s a photo of the pump.

Question for experienced jet boat ppl. Why are some pumps mounted so far back?

Only problem I see with this set up is The clean out port might be a pain in the azz as I think water will come into the boat if it’s opened and not on land.

 

[neilsleder]

Similar engine builds seem to make around 750 hp. however the cam I got is not going to get it close to the hp that it could make. I’m shooting for 550 ish hp and a ton of torque. This boat won’t need that extra 200 Hp as I have no intention of doing 90mph on the water. The 550 will push the boat around just fine for what I want. The extra 200hp I’m leaving in the table takes fuel to make.

Here’s a photo of the pump.

Question for experienced jet boat ppl. Why are some pumps mounted so far back?

Only problem I see with this set up is The clean out port might be a pain in the azz as I think water will come into the boat if it’s opened and not on land.

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//uploads.tapatalk-cdn.com/20210322/52184a11c102f8a9b72ba7ca05e8695d.jpg

I think the only reason really is for more interior room. Maybe for the boat to run a little more nose high.

 

[pfi572]

Similar engine builds seem to make around 750 hp. however the cam I got is not going to get it close to the hp that it could make. I’m shooting for 550 ish hp and a ton of torque. This boat won’t need that extra 200 Hp as I have no intention of doing 90mph on the water. The 550 will push the boat around just fine for what I want. The extra 200hp I’m leaving in the table takes fuel to make.

Here’s a photo of the pump.

Question for experienced jet boat ppl. Why are some pumps mounted so far back?

Only problem I see with this set up is The clean out port might be a pain in the azz as I think water will come into the boat if it’s opened and not on land.

//uploads.tapatalk-cdn.com/20210322/89eed18d4c27f70250764855349ee0fc.jpg
//uploads.tapatalk-cdn.com/20210322/52184a11c102f8a9b72ba7ca05e8695d.jpg

Probably turn pump at 46-4700 rpm with that targeted hp .
Yeh look for a aggressor bowl with a zipper on it . Hard to find but some out there . The bowl helps with performance as well .
Do not pull clean out cap off without everyone in the boat standing on the nose or boat or in shallow water . Lol

 

[neilsleder]

Probably turn pump at 46-4700 rpm with that targeted hp .
Yeh look for a aggressor bowl with a zipper on it . Hard to find but some out there . The bowl helps with performance as well .
Do not pull clean out cap off without everyone in the boat standing on the nose or boat or in shallow water . Lol

It comes in pretty fast lol. That was the nice thing about my jmax motor. Could pull it and no water would come into the boat.

 

[pfi572]

It comes in pretty fast lol. That was the nice thing about my jmax motor. Could pull it and no water would come into the boat.

With a big block it comes in really fast .
Always check the cap afterwards as well for leaks . Have seen boats sink due to leaking . Lol
Camping out over night and partying on shore , guy goes down to get something out of boat and it’s gone with a very tight bow rope showing . Lol
Deep water on a lake . They had been into pumps earlier in the day to dig out some sticks .

 

[NoBrakes!]

mines welded shut....

 

[Dragonalain]

mines welded shut....

I’m sure I’ll get some rope wrapped up in mine I’m lucky that way. Good to know to double check the seal tho.

 

[Dragonalain]

Pulling the 35 year old foam out today. Glad I decided to as it’s water saturated and it’s been in a shed since 1993. It could be from the pressure washing I did this fall/winter but if it’s that full of water from that it would be awful ones it gets used.

2.5 bags from this side at 22 pounds each.

 

[Dragonalain]

Probably turn pump at 46-4700 rpm with that targeted hp .
Yeh look for a aggressor bowl with a zipper on it . Hard to find but some out there . The bowl helps with performance as well .
Do not pull clean out cap off without everyone in the boat standing on the nose or boat or in shallow water . Lol

Can someone fill me in what a zipper is on a bowl? I looked on line a bit and have no idea what I’m looking for .

 

[HotShotHarry]

I am also wondering ..

 

[pfi572]

Can someone fill me in what a zipper is on a bowl? I looked on line a bit and have no idea what I’m looking for .

A brass ring with a lip is bolted to transom with the bowl bolts .
The bowl is machined with a lip on it and then a split clamp with a bolt on each side that sucks the clamp tight around the brass ring and the bowl holding it on .
Takes a couple minutes to install or remove as don’t have to get inside boat to remove the ring of bolts the would normally hold the bowl on .
I had one on my old 1986 Marathon .
I will try and find a picture.

I think it’s Rodger at Explorer Industries used to build them back then . I will have to check on that .
Confirmed that Explorer has done them . They will need your bowl to machine the forward face as well .

 

[tejay]

Dammit I keep clicking on this topic thinking I will be seeing titties and skimpy bikinis but nooooooo

 

[Dragonalain]

A brass ring with a lip is bolted to transom with the bowl bolts .
The bowl is machined with a lip on it and then a split clamp with a bolt on each side that sucks the clamp tight around the brass ring and the bowl holding it on .
Takes a couple minutes to install or remove as don’t have to get inside boat to remove the ring of bolts the would normally hold the bowl on .
I had one on my old 1986 Marathon .
I will try and find a picture.

I think it’s Rodger at Explorer Industries used to build them back then . I will have to check on that .
Confirmed that Explorer has done them . They will need your bowl to machine the forward face as well .

I have access to the tools to build that but it sounds like more work than I want to do lol. I was thinking I would run some counter sunk bolts through the transom into the pump so if I do take it off it will stay sealed. Idk maybe that’s also a waste of time.

 

[neilsleder]

Anyone need a sport jet impeller fixed up be summer? Going to do my neighbours Hamilton 212 to see how that goes. Rather experiment on his then someone else’s.

 

[snoflake]

How much to get a 3.4 hammi impeller built up?

 

[neilsleder]

How much to get a 3.4 hammi impeller built up?

I will let you know in a bit. I see my buddy has his boat home now so hopefully he gets it torn apart and I can do it. But a rough guess is about $500.

 

[snoflake]

Sounds good.

 

[NoBrakes!]

Dammit I keep clicking on this topic thinking I will be seeing titties and skimpy bikinis but nooooooo

I agree. lets see em