SoCal Jet Boats
Tech Talk => Engine Mechanical / Electrical => Topic started by: Outlawmayhem on March 17, 2016, 03:11:23 PM
-
I was looking at going 521 stroker...
now im leaning towards punching the cylinders out .30 changing pistons to bump up the compression.
currently building a D1ve block it has d3 heads but this motor will be getting the c9 heads off my other motor with some cleanup.
thinking h beam rods, stock crank, forged pistons? not sure where the compression would be on a d1 block with c9 heads.
starting compression would determine my piston selection. id like to keep it in the 10:1 to 11:1 range and run on 91 octane possibly running a booster if needed.
looking at victor 460 intake.
with this cam kit http://www.summitracing.com/parts/cca-k34-241-5 (http://www.summitracing.com/parts/cca-k34-241-5)
and for the fun of it lets top it all off with a 150 shot.
still trying to figure out what pistons to use.
-
Both would be awesome. What is the cost difference? My last engine was a 460 at .30 over and it ran hard. New one is the 521. What is the pros ans cons?
-
Both would be awesome. What is the cost difference? My last engine was a 460 at .30 over and it ran hard. New one is the 521. What is the pros ans cons?
It seems like it would be cheaper for me to build the .30 over motor I could also forget about the 150 shot and just run my tunnel ram that would shave about 1000 bucks off the build. It's a lake boat that will mostly be cruised except when I'm out running it against friends.
-
Sounds like you have your answer. Now get on it! Summer is ah comin
-
Sounds like you have your answer. Now get on it! Summer is ah comin
Haha the motor in the boat is running good right now. This is a build that'll go in next year.
-
I just bought the rotating assembly from Scat to make the 521 motor, $3100 with a few upgrades and tax (I'm in CA).
😳
Food for thought on what direction to go..
Steve-O
-
I was looking at going 521 stroker...
now im leaning towards punching the cylinders out .30 changing pistons to bump up the compression.
currently building a D1ve block it has d3 heads but this motor will be getting the c9 heads off my other motor
thinking h beam rods, stock crank, forged pistons? not sure where the compression would be on a d1 block with c9 heads.
starting compression would determine my piston selection. id like to keep it in the 10:1 to 11:1 range and run on 91 octane possibly running a booster if needed.
looking at victor 460 intake.
with this cam kit http://www.summitracing.com/parts/cca-k34-241-5 (http://www.summitracing.com/parts/cca-k34-241-5)
and for the fun of it lets top it all off with a 150 shot.
still trying to figure out what pistons to use.
A zero decked OEM 460 short block with flat top pistons and early heads will put you at about 11.75: 1 c/r. The Keith Black Icon IC635 forged piston with 15ccs of dish will put you at about 10.5:1. Frankly I think that's a bit steep for straight pump gas, but blending some 100LL could make it work if you're diligent about staying with it.
As far as shelf cams go, the one linked would suit such a combo well provided the port work is good.
Personally I'd opt for compression ratio just below 10:1 but budget 22cc dished pistons are in short supply at the moment (unless you opt for the 2404). Another option is to use a flat top pistons and ported D3VE's (9.9:1 c/r) but then you've the valve train mods to deal with for your selected camshaft....so it's a wash either way.
-
A zero decked OEM 460 short block with flat top pistons and early heads will put you at about 11.75: 1 c/r. The Keith Black Icon IC635 forged piston with 15ccs of dish will put you at about 10.5:1. Frankly I think that's a bit steep for straight pump gas, but blending some 100LL could make it work if you're diligent about staying with it.
As far as shelf cams go, the one linked would suit such a combo well provided the port work is good.
Personally I'd opt for compression ratio just below 10:1 but budget 22cc dished pistons are in short supply at the moment (unless you opt for the 2404). Another option is to use a flat top pistons and ported D3VE's (9.9:1 c/r) but then you've the valve train mods to deal with for your selected camshaft....so it's a wash either way.
Advice worth listening to. LakesOnly, we spoke recently on the phone about the build on our BBF with a blower and 521 combo; appreciate your insight and am following it to a T.
Steve-O
-
Advice worth listening to. LakesOnly, we spoke recently on the phone about the build on our BBF with a blower and 521 combo; appreciate your insight and am following it to a T.
Steve-O
Damn! I would LOVE to see that!
-
Damn! I would LOVE to pay the fuel for that!
Fixed it for ya
Dan'l
-
A zero decked OEM 460 short block with flat top pistons and early heads will put you at about 11.75: 1 c/r. The Keith Black Icon IC635 forged piston with 15ccs of dish will put you at about 10.5:1. Frankly I think that's a bit steep for straight pump gas, but blending some 100LL could make it work if you're diligent about staying with it.
As far as shelf cams go, the one linked would suit such a combo well provided the port work is good.
Personally I'd opt for compression ratio just below 10:1 but budget 22cc dished pistons are in short supply at the moment (unless you opt for the 2404). Another option is to use a flat top pistons and ported D3VE's (9.9:1 c/r) but then you've the valve train mods to deal with for your selected camshaft....so it's a wash either way.
I was looking at having the block decked but keeping the pistons. 020 below deck. And running 15cc dish pistons. As well as a .040 compressed head gasket thickness.
If my calculations are correct that should bring it to around 10:1 I wouldn't mind splashing some 100ll into it. Or even keeping race fuel on hand to add in at every fill up.
-
I was looking at having the block decked but keeping the pistons. 020 below deck. And running 15cc dish pistons. As well as a .040 compressed head gasket thickness.
If my calculations are correct that should bring it to around 10:1 I wouldn't mind splashing some 100ll into it. Or even keeping race fuel on hand to add in at every fill up.
.060 quench distance? Thoughts please LakesOnly?
Feels like a bad idea to me.
-
I was looking at having the block decked but keeping the pistons. 020 below deck. And running 15cc dish pistons. As well as a .040 compressed head gasket thickness.
If my calculations are correct that should bring it to around 10:1 I wouldn't mind splashing some 100ll into it. Or even keeping race fuel on hand to add in at every fill up.
Uhm, no.
-
Uhm, no.
Too much quench distance? Maybe I'll just zero deck the block and run 22cc dished pistons.
-
Too much quench distance? Maybe I'll just zero deck the block and run 22cc dished pistons.
I was always told .035" to .045" quench distance on a big block (and for that matter, long stroke small blocks). I feel that with the compression ratio you are going to end up with, this will be a seriously detonating nightmare.
This is just my opinion, I'm not a machinist by any stretch, but I dont feel you will be succesful opening things up that much.
GT
-
I was always told .035" to .045" quench distance on a big block (and for that matter, long stroke small blocks). I feel that with the compression ratio you are going to end up with, this will be a seriously detonating nightmare.
This is just my opinion, I'm not a machinist by any stretch, but I dont feel you will be succesful opening things up that much.
GT
I've rebuilt motors before but never for performance just stock rebuilds. I definately want to do it right. I'd hate to build it and have it blow up on me
-
I was always told .035" to .045" quench distance on a big block (and for that matter, long stroke small blocks). I feel that with the compression ratio you are going to end up with, this will be a seriously detonating nightmare.
This is just my opinion, I'm not a machinist by any stretch, but I dont feel you will be succesful opening things up that much.
GT
Think my quench distance was .038 on this build. My bro seemed satisfied with that. Now gt says it is cool, double confidence now.
-
Fixed it for ya
Dan'l
Lol. Yep, definitely not going eco friendly.
Good info on this thread.
Steve-O
-
Lol. Yep, definitely not going eco friendly.
Good info on this thread.
Steve-O
Lol! If you ever bring up the words eco or gas mileage with your build then you are doing it wrong.
-
Lol! If you ever bring up the words eco or gas mileage with your build then you are doing it wrong.
I don't know. ....
I was talking to a dude last week who bought a wrecked Eco-Boost pick up and was going to put it in his river boat.
I'm thinking that things going to rock.
GT
-
I don't know. ....
I was talking to a dude last week who bought a wrecked Eco-Boost pick up and was going to put it in his river boat.
I'm thinking that things going to rock.
GT
That would be a wicked motor in a sand rail. Might leave you torque deficient in a jet boat.
Steve-O
-
I don't know. ....
I was talking to a dude last week who bought a wrecked Eco-Boost pick up and was going to put it in his river boat.
I'm thinking that things going to rock.
GT
Well if anyone was going to prove me wrong with random, whacky facts.....it would be you gt. Lol
-
That would be a wicked motor in a sand rail. Might leave you torque deficient in a jet boat.
Steve-O
He's telling me 370 hp at well over 400ft/lbs of torque, I think it's rated at 5,000 rpm, the torque curve probably peaks at about 3,000 rpm though. IDK.
The thing might kick ass.
GT
-
Well if anyone was going to prove me wrong with random, whacky facts.....it would be you gt. Lol
Just trying to get you to keep an open mind brah.
Lmao
GT
-
He's telling me 370 hp at well over 400ft/lbs of torque, I think it's rated at 5,000 rpm, the torque curve probably peaks at about 3,000 rpm though. IDK.
The thing might kick ass.
GT
That would be a wicked motor in a sand rail. Might leave you torque deficient in a jet boat.
Steve-O
Put a gear box on it
-
Too much quench distance? Maybe I'll just zero deck the block and run 22cc dished pistons.
And now back to our regularly scheduled programming...
I know a full-dish with a smaller combustion chamber will make more power. This is opposed to a flat top or a dish with a shape that mirrors the combustion chamber.
I have a theory why this is (to some extent). What I am trying to wrap my head around is: A full-dish opens up some of quench area, why doesn't this contribute to detonation?
-
I was looking at having the block decked but keeping the pistons. 020 below deck. And running 15cc dish pistons. As well as a .040 compressed head gasket thickness.
The effectiveness of quench can be a bit counter-intuitive at first, and so I can understand how it might seem that leaving the pistons in the hole woudl lower compression and thereby reduce detonation, but the resulting lack of quench actually makes detonation more likely. And so conversely, while zero-decking the block may increase compression ratio the simultaneous increase in quench effectiveness greatly surpasses the modest compression increase.
If my calculations are correct that should bring it to around 10:1. I wouldn't mind splashing some 100ll into it. Or even keeping race fuel on hand to add in at every fill up.
OEM early heads are typically 77cc's from the factory; with the addition of large valves the chamber volume drops to about 74cc typical. Any chance you're porting the heads yourself? If so, perhaps you can grind/shape/polish the combustion chambers and get about 5ccs back into them, to about 78-79ccs. If so, then c/r would drop to about 10.1:1 with the Icon pistons I mentioned earlier. Might be a long way to get there but if you're motivated/enthusiastic about doing your own stuff like I am then it's not so bad. PS: Check the heads for flatness and if they don't need surfacing then bypass that step since it lowers chamber volume as well.
-
The effectiveness of quench can be a bit counter-intuitive at first, and so I can understand how it might seem that leaving the pistons in the hole woudl lower compression and thereby reduce detonation, but the resulting lack of quench actually makes detonation more likely. And so conversely, while zero-decking the block may increase compression ratio the simultaneous increase in quench effectiveness greatly surpasses the modest compression increase.
OEM early heads are typically 77cc's from the factory; with the addition of large valves the chamber volume drops to about 74cc typical. Any chance you're porting the heads yourself? If so, perhaps you can grind/shape/polish the combustion chambers and get about 5ccs back into them, to about 78-79ccs. If so, then c/r would drop to about 10.1:1 with the Icon pistons I mentioned earlier. Might be a long way to get there but if you're motivated/enthusiastic about doing your own stuff like I am then it's not so bad. PS: Check the heads for flatness and if they don't need surfacing then bypass that step since it lowers chamber volume as well.
I've never ported and polished heads before. I'd like to do it myself but I figure I would have it done while I get the bigger valves put in em.
-
Well looks like Ill be building a motor alot sooner than I thought. Crank is moving up and down and engine is knocking.
-
What were you doing when it gave out? See oil pressure drop?
-
What were you doing when it gave out? See oil pressure drop?
My oil pressure gauge isn't working so no clue if it dropped out. Wasn't pushing it too hard. Was going 41mph on GPS the tach said 2300rpm but I'm thinking it was more like 3800. I'm thinking i lost oil pressure.
-
For the next engine I am going to need you to have working gauges....mmmmmkay? Lol
-
For the next engine I am going to need you to have working gauges....mmmmmkay? Lol
That's the plan. I'm going to rewire the boat while I have the engine and interior out.
-
Okay so I got the heads off the d1 block. I'm going to definately need to take the block and have it taken 30 over. Cylinders all pretty much rusted to the point the engine won't rotate. I'm hoping the crank and Rods are okay. I can see some rust on the cam but that's getting replaced.
Noticed the pistons are half dish. Running those with c9 heads should net me around 9:1 compression and flat tops 10:1?
Thinking this cam http://m.summitracing.com/parts/cca-k34-232-4
With a little port and Polish on the c9 heads. And either the edelbrock Victor intake or the offy tunnel ram I have with dual quads on it.
-
I have a 460 zero deck 22 dish pistons 30 over a mild cam 108 loobe separation I am 231 at 50 I believe and 256 overall lift and I have dove heads ported and polished larger valves and when they ported it they opened it up the chamber up too much so my chamber is 83cc I made 470 horse with 525 foot pounds of torque starting at 2800 RPM
Sent from my iPhone using SoCal Jet Boats
-
I have a 460 zero deck 22 dish pistons 30 over a mild cam 108 loobe separation I am 231 at 50 I believe and 256 overall lift and I have dove heads ported and polished larger valves and when they ported it they opened it up the chamber up too much so my chamber is 83cc I made 470 horse with 525 foot pounds of torque starting at 2800 RPM
Sent from my iPhone using SoCal Jet Boats
Damm nice. I need to put this motor together on the quickness summer is coming
-
For the next engine I am going to need you to have working gauges....mmmmmkay? Lol
Well there's the main bearing. Found the oil pump shaft in the pan. Not sure how it got there.