Boat engine help..

New here and looking for some input on a engine I am trying to build for my jet boat..I have been doing a lot of reading and talking to people to get info... This post is kinda all over the place so bare with me

This is what I have


Gen 4 block 2bolt-needs convert to 4 bolt or just get a 4 bolt block
427 crank
need rods
trw pistons-70119
cam??
roller lifters??
push rods I have 3/8 what size do i need??7/16 1/2??
Brodix bb2 plus made in 2000
comp cams 1.7 rockers
littlefield intake with burst pannel
14/71 littlefield blower with tefflon strips
enderle bird catcher hat
110 pump
Set up for alcohol

Should I run the TRW pistons? With the 119cc heads It should be around 10 to 1?? If not what brand and should I bump the compression up?

Can I get away with forged GM crank?? If not what brand has treated you good and not broke the wallet?Howard,Scat,Callies....

What rods do you recommend?? steel rods eagle,scat??

What hp should this make?? 1000??

I am kinda stuck between sell my short block and buy new or is it worth it to use what I have I am not looking to get every last HP out of it..Any input would be great..I dont know if theis is the right site to ask if not can you send me in the right direction

Any links of similar builds?? Thanks

 

I cannot help you but it would help if you could post on what performance you would like to achieve, and what purpose this boat is going to do .Like drag racing it depends on your budget and your goals that you set out to achieve. More money makes more fun.

 

The boat is a river/race deal.. Trying to build it on a lower budget if there is such a thing.. As fas as performance I am looking for the most I can get with a good size window as to not blow the bottom end out being as this is my first blown injected alky engine.. From what I have learned they have a pretty good size tuning window and are more forgiving than gas..

 

In order to get a correct answer one will still require some more info. Who are you racing and what do they have for boats and motors. No use building a 700 hp motor to race someone with 1500. the more information you can get will save you from spending money on the wrong motor. Also find out if there is any restrictions that too would be helpful and might save you from wasting money on wrong parts. The reason is you can spend alot of money quick that you may not have to if you go with top of line parts for high horsepower motor that will be over kill for what you want.

 

I got ya..By river/race I mean not sanctioned event or class..Just on the river where we boat the average boat would have around 800 hp.. I would say I would be happy with 1000 1100..

Thanks Pat...Hard to get information out of me

 

thats not alot of horsepower and to save money i would go on a budget. You can get a good deal from eagle for a crank and rods combo as far as pistions go i would go with something like SRP just make sure they are blower pistons the rest of the motor is up to you for heads intake etc. With this being your first attempt keep it simple with fuel and blower system it can be a headache it you make it too complicated. Find a good machine shop and let them help with part selections and when it comes down to fuel system it is better to get help to setup and explain changes that need to help. One downfall with alcohol is you burn twice as much as fuel. Also its up to you on the block talk to machine shop they may have 4 both main block for cheap. My first motor was a Cast iron chevy small block with 4 bolt main with eagle and srp parts with edelbrock rpm heads and i was happy with performance. Like i said keep it simple and let it be a learning experience.

 

as far as a good compression ratio that will work you will need to know how much overdrive that blower is and how much boost you expect to achieve and then have injection system setup for that .your fuel pump might be to much for what you require the person that you get to assist in your setup will be able to better answer that when you have motor info to give to him . Being a boat i would assume you will have to run coolant unlike alcohol cars that run for such a short period of time. the question is how much fuel will you require to run and will gas be better. fuel tank capacity? the injection hat can be converted easy. ONE important question i failed to ask was the downfall of this injection system is there are not for really designed to operate like carbs for part throttle on and off like street cars. BDS makes a injection system designed for this purpose.

 

The first thing you need to know is that everyone on the rivers and lakes lie about how much horsepower they really have. (Trust me. As a hardcore river hitter, I know this all too well. And the last three engines I have built are all river boats. I have a pump gas 330 inch small block with a single carb that throws blown alcohol boats off the water all of the time.)
Then you need to look at your pump. A huge horsepower engine running at 7800rpms does nothing in a jet. Jet impellers and pumps do not like rpms. They do not work at those rpms. So, what impeller and pump do you have? Most likely you are looking at rpm schedules between 5600 and 6200. So the cam needs to refelct that desire. A cam that will work there is great. These guys that build a jet engine that makes killer power at 7600 just shot themselves in the foot. The key to winning on the river is to utilize your horsepower and maximize your set up. Set the engine to run where your ditch pump wants it to run.
Your parts are fairly mis-matched, but should be able to work for your application and keep the $$$ down. But you are going to need to keep your blower overdrive light, and your timing light. More timing creates more hit on the rods/crank/bearings/block. And since yours are fairly weak, just keep that in mind. Grab a set of eagle rods and you should be O.K. with your current set up.
The TRW's are heavy pistons, but again, at lower rpm's, they will be decent.
The crank should be fine, but don't lean on it too much.
Lots of machine shops that convert a 2 bolt block actually have a weaker block when finished as a four bolt. (The webbing there is fairly weak, and you drilled more holes into it, and threaded it - making it even weaker.) But four bolt blocks are cheap.
Yes, run alcohol. (Or E85, the ethanol pump gas.) You will need the wider tuning window for your part throttle, on and off the throttle, etc. Trying to go blown/injected on gasoline for a boat is friggin' rocket science. You just can't get mechanical injection right accross the full opperating ranges of a lake boat. No one can, so don't go broke trying it.
If you are wise enough to heep the rpms down, you can keep spring pressures down, and then run less expensive roller lifters. And as for pushrods, get the biggest that you can easily fit in regards to the clearance from your heads.
And remember; wisdom always prevails on the river. Run the thing light and it won't be blown up all of the time like your competition. Build it according to what your boat and your pump wants, and watch the guys boasting 500 more horsepower dissappear and catch a full view of your transom as you walk away from them. Then, when you tell them your 850 horsepower mill really makes 1400, they will believe you all day long.
Also remember, boats are supposed to be fun. So keep the build strong, and the tuning on the light side. It will last so much longer that way.
Good luck!

 

Thanks for all of your input on this...

I have a California Performance Tunnel with a Berkley pump "B" stainless impeller..But with the power this should make I am thinking I should bump up to a A or AA...

When I said 1100 hp I really did not know what to expect out of a 440" ci motor with my heads but it looks like you guys are making that pretty easy and then some..

If I was to buy a new rotating assembly should I stay with the 440" deal or biuld a 496 or something like that?? ,My understanding is that with the 3.760 crank it has better rod angle making life easier on the engine..But also spins higher RPM that would not be use full in my application...

Also found a Callies Compstar Compweight BBC 3.760 Stroke for 500 bucks from Callies..Is that worth buying or are they not as good because they are made over seas..Better than a Scat, or Eagle???

 

ok..i have a ta/d dragster...but also a blown flat bottom jet if you wanna give me a call sometime I would love to talk boats, at one time i was going to run a capsule boat untill Eddie Hill taked me out of it...thanks Eddie Im still alive... but my flat bottom will run 110 to 115 with no problem, it has a 427 big block chevy mert 8-71 or i might have put the 10-71 on cant remember, one thing build a kick ass bottom end these bad boys are death on motors I've kick more rods out of this thing than my TA/D..also spend the money and send your pump off and I would send it to Dons pump service in andover kansas. I have been messing with boat for 30 years and still learing we live on a lake in the summer so I have lots of time to tear things up...Dave
620-249-5909
race shop 620-231-8068
if you go to face book look me up secondwind racing Dave Lowe there is pics of our boats on there

 

Here's the combo in our flat. 565 BBC, Dart 355 CNC heads, 10.5:1 CR, .700" lift roller cam, 8-71 Littlefield at 4% under, everything through the hat, 80A-1 fuel pump, and a MSD 12 Pro mag. We used GRP aluminum rods, but in retrospect, I wish I had used a high quality steel rod. Made 1180@ 7200 RPM and over 1000 ft/lbs tq from about 3k up. We run 7.70s at 139 MPH.
Bottom line is, a stout short block with decent heads on alcohol, will make 1100 HP easily and live if you do it right. The late Denis Porter was making about 1200 HP with a 427, 6-71 (spinning the snot out of it) and a vertex mag in his Cole flat... Best of luck...

 

hey dave, sounds like that boat scoots.....have you ever put so OD to the blower? just woundering I bet it would skate..take care and you gota love them boats...dave SWR

 

The only thing I can add to this is make sure you get with a cam grinder for a specific jet-boat cam. If it was me, I would build a combo that put out max torque and HP in the 6000-6800 rpm range because that is about all a jet pump is going to let you turn. If you're doing a lot of river running I would keep the B-impeller, an A or AA will have so much more slippage when just cruising, think you would really be unhappy with it over time. All the looser impellers do is allow a little higher rpm range because of slippage, they don't pass any more water through the pump, best analogy I can think of is trying to run a 8-inch 6000 stall speed convertor on the street. Glad you've got a stainless impeller, a good blower motor will make short work of a cast Berkeley impeller. Last thing you want is a big hole in the side of your pump bowl. Havn't been on this site for a while but it might be worth joining or even just lurking.

http://dragboatalley.com/ubb/ultimatebb.php

 

Never really leaned on the tune up. We have a port nozzle set up and pullys to go about 25% over, but never tried them. Our index is either 7.70 or 8.0 depending on which class I run so never had the need. Also, one association limits us to 7.70 ET and the other limit's flats to 145 MPH, so going about as fast/quick as they let an open flat run...

 

the pic you showing looks like my taf i ran 5 years ago if the number is 820 on the side

 

Boat motor

I have a 482 ci kb tall deck with brodex weld tec heads jessel shaft rockers rcd front drive 8 mm pulleys msd 20 with two point boxes psi screw blower, psi low profile injector with k valve grp rods zoomes for boat, water block, this is a blowen gas engine.
I l interested give me a call $18,000
Dave Sharp
1 520 798 1728
hydrotherapy715@yahoo.com

 

if your going to build a motor you need good parts not everyday street parts good forged pistons rods depending what your tring to do is this a race boat are a pleasure boat that you want to show off and beat your buddys with like some one said above horse power most just guess on horse power unless its been on a dyno a jet boat can get to a 100mph pretty easy without a blower it can be done with a good motor and a reworked jet pump most blower motors i have seen on the river run chillers also unless its an all out drag doat there are many ways to go here less weight you can get away with less horse power and on an on