Stroker kits are inexpensive for the BBF. nothing like an extra 97 or so cubic inches to increase the power in a jet boat. they do have 12:1 compression so I run 50-50 mixed AV gas and 87 octane.
As for these kits, it is possible to build one with a more reasonable (family boat) compression ratio is it not?
Most of the stroker kits are dish piston deals so depending on combustion chamber size you go with will determan how much compresion you make. Most are in the area of 9-1 - 9.8-1. In all actuality very usable. The kit prices are fairly cheep. But I would never ever just slapp one of those kits together ececpt for preassembly fit and clearance check.
Jim
I intend to put together another 557 this winter for my 23' boat and shoot for pump gas by using D3 heads with larger combustion chambers. I think I can get away with pump gas at 10:1. I will try to avoid the dish pistons if possible because with flat tops, I'll have three identical short blocks in all my boats and I already have seven spare pistons due to having to buy a set to replace one piston when I lost a head gasket last year. These are in no way maximum effort engines. if they were, the hard parts may not be strong enough. they are fine for easy running torque and low rpm use. lots of my friends run blown BBC and I spank them regularly.
I intend to put together another 557 this winter for my 23' boat and shoot for pump gas by using D3 heads with larger combustion chambers. I think I can get away with pump gas at 10:1. I will try to avoid the dish pistons if possible because with flat tops, I'll have three identical short blocks in all my boats and I already have seven spare pistons due to having to buy a set to replace one piston when I lost a head gasket last year. These are in no way maximum effort engines. if they were, the hard parts may not be strong enough. they are fine for easy running torque and low rpm use. lots of my friends run blown BBC and I spank them regularly.
I have 10.3:1. I run pump gas with no problems. The motor just dose not run under water!! :hammer2:
Most of the stroker kits are dish piston deals so depending on combustion chamber size you go with will determan how much compresion you make. Most are in the area of 9-1 - 9.8-1. In all actuality very usable. The kit prices are fairly cheep. But I would never ever just slapp one of those kits together ececpt for preassembly fit and clearance check.
Jim
I'm going to run up to the boat this afternoon and grab some numbers off of it to set a better starting point. I know I've looked up the heads before but can't for the life of me remember what they are.
Am I wrong in thinking that with a stroker kit, head selection would be even more critical or will the extra displacement allow a more "forgiving" selection?
Pete
just because you have lots of hp dosnt mean that your motor will have to be worked on all the time once set up properly you will have very low maintance( adjusting your valves a couple times a year and oil changes)
i would say that the stroker kit will make the head selection very important. more displacement = more air in/out so your going to want to look at your options very closely.
good luck and by the way my boat was a family river boat as well
LO,
Thanks for the response, in order to keep this tidy I will get all the info together and post it as soon as it is complete.
Pete
Standing by...
Paul
Here you go LO;
I would like to know what you have for factory iron, namely block and head casting numbers and even the intake manifold casting number.
Block = F161248
Heads = D3VE A2A
Manifold = Edelbrock, single plane I beleive but no markings.
Will you use thru-transom exhaust or over-transom headers? Finally what brand pump and impeller do you have?
Headers = Rewarder OT with baffles
Pump = Berkeley 12JC-A. I beleive it still has the original A impeller but have never
confirmed it.
Are you looking for a substantial speed gain?
No but I am not opposed to it if. ie. if a 15 % increase in performance can be built in
with out a 15% expected decrease in reliability and the cost to do so is an additional
10%, that seems worth the investment to me.
Is fuel usage a major issue?
On a scale of 1-10 IÂ’d say itÂ’s about a 5. I only have a 20 Gallon capacity and when
we are in the boat weÂ’re moving so it is of concern.
How do you feel about adjusting your valves once or twice a yearÂ…yes or no?
Yes, not a problem.
If you believe you will continue to use your boat as you have already explained--but would just like some more power with your reliability--then your build is easy and can be accomplished with little effort or cost.
Your above statement pretty much hits the nail on the head.
Please......stab away
Pete
Pete,
I will be posting two or three builds. One will be graduated from the next, and so you will be able to compare/contrast and decide what you want.
These will take some time to write out. I've already started but must attend to personal business tonight. I'll have them posted by 12 noon tomorrow.
Stand by,
LO
ps: three follow-up Q's:
1) Do you know if the 460 in the boat is the original engine that came with the boat when new?
2) Has it ever been rebuilt?
3) The block casting number is located behind the starter motor and reads vertically. Can be C8VE-A, C9VE-A, D0VE-A, D1VE-(xxxx) or D9TE.
Pete,
I will be posting two or three builds. One will be graduated from the next, and so you will be able to compare/contrast and decide what you want.
These will take some time to write out. I've already started but must attend to personal business tonight. I'll have them posted by 12 noon tomorrow.
Stand by,
LO
ps: three follow-up Q's:
1) Do you know if the 460 in the boat is the original engine that came with the boat when new?
2) Has it ever been rebuilt?
3) The block casting number is located behind the starter motor and reads vertically. Can be C8VE-A, C9VE-A, D0VE-A, D1VE-(xxxx) or D9TE.
Take your time, I might not be able to respond until late tomorrow due to work.
As for the follow up Q's:
1)I do not know for sure but from what I can ascertain, it most likely is.
2)Rebuilt, I don't know. Modified, I would say yes, it most defiantly has a cam.
3)Sorry, I new that was to easy.
Thanks again, Pete
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