Marine Chevy 350 Build ?
04-27-2009, 11:07 PM
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Marine Chevy 350 Build ? Thanks in advance for any help you guys give me.
Okay so I am missing a few particulars and I apologize for that.
In a nutshell I have found a Marine engine that I am thinking about puttin into my jeep. I am only looking for something around 325-350 Hp. But I would like a good ammount of torque.
This engine is ready to be assembled and everything is there and in brand new condition. Its at my mechanics shop and he just hasn't gotten to put it together. Its a early 90's block with 2 bolt mains and and one piece rear oil seal. He said it has a 300 dollar custom ground Cam (I am sorry I don't know the specs) that is susposed to be bad ***. Now the part worrying me is that it has 191 heads. I think they are like 76cc. They are basically new. But even if the cam and other components are really nasty would it "overcome" the heads to make my desired power? He has a electronic ignition and a quadrajet carb to put on the engine.
I guess basically I am wondering what these heads potential is? I am sorry I am vague on the cam info I will try to find out tomorrow and get back to everyone. Thanks
Brian
Okay so I am missing a few particulars and I apologize for that.
In a nutshell I have found a Marine engine that I am thinking about puttin into my jeep. I am only looking for something around 325-350 Hp. But I would like a good ammount of torque.
This engine is ready to be assembled and everything is there and in brand new condition. Its at my mechanics shop and he just hasn't gotten to put it together. Its a early 90's block with 2 bolt mains and and one piece rear oil seal. He said it has a 300 dollar custom ground Cam (I am sorry I don't know the specs) that is susposed to be bad ***. Now the part worrying me is that it has 191 heads. I think they are like 76cc. They are basically new. But even if the cam and other components are really nasty would it "overcome" the heads to make my desired power? He has a electronic ignition and a quadrajet carb to put on the engine.
I guess basically I am wondering what these heads potential is? I am sorry I am vague on the cam info I will try to find out tomorrow and get back to everyone. Thanks
Brian
04-28-2009, 05:27 PM
#2
www.mortec.com says:
14102191...87-up...350
Doesnt even give a description...which isnt really a good thing.
What you need to do is sell them on ebay to get some money, and buy a set of 1996+ Vortec heads. Either get a set that already has the valve spring seat ground out for larger springs, or have your machinist do it. With doing that, you'll also need to make the hole for the push rod larger as well. You'll also need the valve stem seat ground down to clear lifts more than .480.
This is what your looking for:
10239906...96-up...350.........."Vortec 5700", "L31", 64cc chamber,
170cc intake port, 1.94"/1.5" valves
Theres also a casting number ending in "062" that are the same and can be used as well like the "906" castings.
14102191...87-up...350
Doesnt even give a description...which isnt really a good thing.
What you need to do is sell them on ebay to get some money, and buy a set of 1996+ Vortec heads. Either get a set that already has the valve spring seat ground out for larger springs, or have your machinist do it. With doing that, you'll also need to make the hole for the push rod larger as well. You'll also need the valve stem seat ground down to clear lifts more than .480.
This is what your looking for:
10239906...96-up...350.........."Vortec 5700", "L31", 64cc chamber,
170cc intake port, 1.94"/1.5" valves
Theres also a casting number ending in "062" that are the same and can be used as well like the "906" castings.
04-28-2009, 09:36 PM
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www.mortec.com says:
14102191...87-up...350
Doesnt even give a description...which isnt really a good thing.
What you need to do is sell them on ebay to get some money, and buy a set of 1996+ Vortec heads. Either get a set that already has the valve spring seat ground out for larger springs, or have your machinist do it. With doing that, you'll also need to make the hole for the push rod larger as well. You'll also need the valve stem seat ground down to clear lifts more than .480.
This is what your looking for:
10239906...96-up...350.........."Vortec 5700", "L31", 64cc chamber,
170cc intake port, 1.94"/1.5" valves
Theres also a casting number ending in "062" that are the same and can be used as well like the "906" castings.
14102191...87-up...350
Doesnt even give a description...which isnt really a good thing.
What you need to do is sell them on ebay to get some money, and buy a set of 1996+ Vortec heads. Either get a set that already has the valve spring seat ground out for larger springs, or have your machinist do it. With doing that, you'll also need to make the hole for the push rod larger as well. You'll also need the valve stem seat ground down to clear lifts more than .480.
This is what your looking for:
10239906...96-up...350.........."Vortec 5700", "L31", 64cc chamber,
170cc intake port, 1.94"/1.5" valves
Theres also a casting number ending in "062" that are the same and can be used as well like the "906" castings.
So I found this for sale:
"062 Casting Vortec Heads, screw in studs and guidplates, new springs, good for 550+ lift, guides cut down. Machine work done 8 months ago, never used. Price includes new intake. Asking 650 for everything"
What do you think? I suppose this would make it scream. I thought my mechanic said today that it was a 272 ultradyne cam. Not sure if that makes any sense. I need to ask and write it down.
Now I am wondering if the 191 marine heads would get me by. My thinking is everyone said the boat went well. I mean it was built to put a 20+ foot scaraab on plane fairly quick it would prob be plenty for a 2000 pound jeep. I dont know about this. Would I get probably 250--275hp? Lot of torque? I have to say my mechanic is a really fair guy and a good friend. I have truly seen it with my own eyes. He even helps me use his shop to fix stuff and doesn't charge me. So I really dont think he would bullshit me. He is afraid this engine as is would destroy my rear end. But I am not quite seeing it. I don't know whats your opinion. I wish I had more info on the cam. I think with the vortec its would force me to go to a real heavy duty trans.
04-29-2009, 04:20 PM
#4
Im not sure what rear end or trans you are using but with that cam the motor will make 300-330HP by just guessing the specs. The 272 is probably the advertised duration, which means the duration @ .050 is around 200-220 taking a stab in the dark.
It would make good torque now, but the Vortecs would give it even more on top of that. GMPP had an article a while back that said vortecs even on a stock 350 was worth about 40HP just for bolting them on...which gives you an idea on how good they are/how bad the older heads are. Also, the smaller CC size of the Vortecs is going to raise your compression to around 10:1 which will be great for torque and off idle power, which is where your going to want it.
That deal you found is a excellent deal for sure. Since they have guide plates installed, you wont need to run self-aligning rocker arms (more expensive). Screw in studs are also good so you dont have to worry about the lift of the cam pushed the press-in studs out.
It would make good torque now, but the Vortecs would give it even more on top of that. GMPP had an article a while back that said vortecs even on a stock 350 was worth about 40HP just for bolting them on...which gives you an idea on how good they are/how bad the older heads are. Also, the smaller CC size of the Vortecs is going to raise your compression to around 10:1 which will be great for torque and off idle power, which is where your going to want it.
That deal you found is a excellent deal for sure. Since they have guide plates installed, you wont need to run self-aligning rocker arms (more expensive). Screw in studs are also good so you dont have to worry about the lift of the cam pushed the press-in studs out.
04-29-2009, 04:36 PM
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Im not sure what rear end or trans you are using but with that cam the motor will make 300-330HP by just guessing the specs. The 272 is probably the advertised duration, which means the duration @ .050 is around 200-220 taking a stab in the dark.
It would make good torque now, but the Vortecs would give it even more on top of that. GMPP had an article a while back that said vortecs even on a stock 350 was worth about 40HP just for bolting them on...which gives you an idea on how good they are/how bad the older heads are. Also, the smaller CC size of the Vortecs is going to raise your compression to around 10:1 which will be great for torque and off idle power, which is where your going to want it.
That deal you found is a excellent deal for sure. Since they have guide plates installed, you wont need to run self-aligning rocker arms (more expensive). Screw in studs are also good so you dont have to worry about the lift of the cam pushed the press-in studs out.
It would make good torque now, but the Vortecs would give it even more on top of that. GMPP had an article a while back that said vortecs even on a stock 350 was worth about 40HP just for bolting them on...which gives you an idea on how good they are/how bad the older heads are. Also, the smaller CC size of the Vortecs is going to raise your compression to around 10:1 which will be great for torque and off idle power, which is where your going to want it.
That deal you found is a excellent deal for sure. Since they have guide plates installed, you wont need to run self-aligning rocker arms (more expensive). Screw in studs are also good so you dont have to worry about the lift of the cam pushed the press-in studs out.
Thats acceptible for me. But man those vTEC heads are wicked nice. I want em! LOL but I bet it would devour gas with that much power.
05-02-2009, 12:03 PM
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Hey too late I appreciate all the knowledge. One more thing. With a 64cc head will I be looking at 10:1? Then it would require 92 octane right? I am trying to build something with okay power and will happily take 87. I mean I could grind down some metal in the combustion chamber in an attempt to lower the compression. What do you think?
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05-02-2009, 01:05 PM
#8
really need alot more info to detirmine what heads youd want and estimated HP, what kind of pistons are involved in this buid?? dished, flat tops or domed?? Cam specs are a MUST!! you need to make sure all this stuff is going to match up, or youll have something sounds radical loose street manors but wont get out of its own way and get owned by a 100% stock build.
with 64 cc heads on a flat top your looking at 10 : 1 yes
but if you have dished pistons youll be at 9:1
like wise with your current 76cc heads, flat tops around 9.5 :1
dished 8.5 :1
Cam specs would be very nice!!!! Something big isnt gonna run for **** and make power unless your in the 10:1 compressin range
Push for the exact cam specs.
and do not grind any combustion chambers lol.... if you want 87 octane shoot for 8.5 to 9.5 Compresion ratio with milder parts, but itll hurt NA HP potentials compared to running 10 :1 with better gas and nappier part potentials,
with 64 cc heads on a flat top your looking at 10 : 1 yes
but if you have dished pistons youll be at 9:1
like wise with your current 76cc heads, flat tops around 9.5 :1
dished 8.5 :1
Cam specs would be very nice!!!! Something big isnt gonna run for **** and make power unless your in the 10:1 compressin range
Push for the exact cam specs.
and do not grind any combustion chambers lol.... if you want 87 octane shoot for 8.5 to 9.5 Compresion ratio with milder parts, but itll hurt NA HP potentials compared to running 10 :1 with better gas and nappier part potentials,
05-02-2009, 03:04 PM
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really need alot more info to detirmine what heads youd want and estimated HP, what kind of pistons are involved in this buid?? dished, flat tops or domed?? Cam specs are a MUST!! you need to make sure all this stuff is going to match up, or youll have something sounds radical loose street manors but wont get out of its own way and get owned by a 100% stock build.
with 64 cc heads on a flat top your looking at 10 : 1 yes
but if you have dished pistons youll be at 9:1
like wise with your current 76cc heads, flat tops around 9.5 :1
dished 8.5 :1
Cam specs would be very nice!!!! Something big isnt gonna run for **** and make power unless your in the 10:1 compressin range
Push for the exact cam specs.
and do not grind any combustion chambers lol.... if you want 87 octane shoot for 8.5 to 9.5 Compresion ratio with milder parts, but itll hurt NA HP potentials compared to running 10 :1 with better gas and nappier part potentials,
with 64 cc heads on a flat top your looking at 10 : 1 yes
but if you have dished pistons youll be at 9:1
like wise with your current 76cc heads, flat tops around 9.5 :1
dished 8.5 :1
Cam specs would be very nice!!!! Something big isnt gonna run for **** and make power unless your in the 10:1 compressin range
Push for the exact cam specs.
and do not grind any combustion chambers lol.... if you want 87 octane shoot for 8.5 to 9.5 Compresion ratio with milder parts, but itll hurt NA HP potentials compared to running 10 :1 with better gas and nappier part potentials,
Yeah I am sorry I just dont have the cam specs. My mechanic isn't the best at record keeping and this thing is sitting in his shop disassembled. I guessed as best I can that all I can do for now.
I know for sure it has flat top pistons. I have looked at them.
With flat tops I will get around 9.5:1? That should be plenty for me. I don't need anything too insane and I can alway change the heads or CAM later down the road. If I want more performance.
05-02-2009, 11:19 PM
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One thing aboout the Vortec heads is that they are fairly happy with higher compression than normal on pump gas. I'm not saying you'll be able to run 10:1 and a baby cam on 87, but if it's around 9.5:1 or under with a cam that will bleed off some pressure you should be able to run 87. a nice radiator and some e-fans would help too.
05-03-2009, 06:21 AM
#11
Yeah I am sorry I just dont have the cam specs. My mechanic isn't the best at record keeping and this thing is sitting in his shop disassembled. I guessed as best I can that all I can do for now.
I know for sure it has flat top pistons. I have looked at them.
With flat tops I will get around 9.5:1? That should be plenty for me. I don't need anything too insane and I can alway change the heads or CAM later down the road. If I want more performance.
I know for sure it has flat top pistons. I have looked at them.
With flat tops I will get around 9.5:1? That should be plenty for me. I don't need anything too insane and I can alway change the heads or CAM later down the road. If I want more performance.
I wouldnt run that cam honestly... unless you can get a dial idicator and check atleast the lift.... who knows what the hell it is or if its even any good, could be wiped out for all you know, big no no in my book,
05-03-2009, 09:34 PM
#12
fwiw i would not do a build off a marine engine. first, boat people are usually dumb and misinformed about engines. There's a $300 custom ground cam that came with the engine but the heads are non-vortec and I assume it has the oem manifold?
if the boat was run in salt water and unless you know the engine was not raw water cooled, you can have a decent amount of rust inside the cooling passages that may cause problems if you run it at the typical 180-210F. And most boat people don't maintain or know how to properly maintain the engine so I would be hesitant in throwing money into this build while reusing certain fundamental components such as pistons and valvetrain. I would have the block thoroughly checked first before putting money into it unless all you want is a 350 to drop in your jeep and just run as is. The last thing you want to find out is it had freeze damage and there's a crack somewhere inside. if it were me, i would almost consider passing on the block altogether and find a used auto block to do a smart build on to make power. Just too much risk with a marine engine, and marine engines are usually light years behind auto engines in terms of power output.
if the boat was run in salt water and unless you know the engine was not raw water cooled, you can have a decent amount of rust inside the cooling passages that may cause problems if you run it at the typical 180-210F. And most boat people don't maintain or know how to properly maintain the engine so I would be hesitant in throwing money into this build while reusing certain fundamental components such as pistons and valvetrain. I would have the block thoroughly checked first before putting money into it unless all you want is a 350 to drop in your jeep and just run as is. The last thing you want to find out is it had freeze damage and there's a crack somewhere inside. if it were me, i would almost consider passing on the block altogether and find a used auto block to do a smart build on to make power. Just too much risk with a marine engine, and marine engines are usually light years behind auto engines in terms of power output.
05-03-2009, 11:05 PM
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fwiw i would not do a build off a marine engine. first, boat people are usually dumb and misinformed about engines. There's a $300 custom ground cam that came with the engine but the heads are non-vortec and I assume it has the oem manifold?
if the boat was run in salt water and unless you know the engine was not raw water cooled, you can have a decent amount of rust inside the cooling passages that may cause problems if you run it at the typical 180-210F. And most boat people don't maintain or know how to properly maintain the engine so I would be hesitant in throwing money into this build while reusing certain fundamental components such as pistons and valvetrain. I would have the block thoroughly checked first before putting money into it unless all you want is a 350 to drop in your jeep and just run as is. The last thing you want to find out is it had freeze damage and there's a crack somewhere inside. if it were me, i would almost consider passing on the block altogether and find a used auto block to do a smart build on to make power. Just too much risk with a marine engine, and marine engines are usually light years behind auto engines in terms of power output.
if the boat was run in salt water and unless you know the engine was not raw water cooled, you can have a decent amount of rust inside the cooling passages that may cause problems if you run it at the typical 180-210F. And most boat people don't maintain or know how to properly maintain the engine so I would be hesitant in throwing money into this build while reusing certain fundamental components such as pistons and valvetrain. I would have the block thoroughly checked first before putting money into it unless all you want is a 350 to drop in your jeep and just run as is. The last thing you want to find out is it had freeze damage and there's a crack somewhere inside. if it were me, i would almost consider passing on the block altogether and find a used auto block to do a smart build on to make power. Just too much risk with a marine engine, and marine engines are usually light years behind auto engines in terms of power output.
Haha yah you got it on point. Its stock 76cc heads. Stock 40Lb steel manifold. I think he said 350 dollar custom ground Ultradyne Cam.
From my estimation after looking at the block etc. I can see some rust, etc on the block(Mainly Surface). I also see some corrosion on the stock manifold. The rest of it really looks okay. I mean its disassembled. I guess what happen was the previous owner he built the engine for detionated it by advancing the timing. So he then got it back and the guy went and bought a 383 for the boat.
My mechanic tore the engine apart to determine what kind of shape it was in. Every thing measures out to spec. The pistons look good. The rings still have the factory machining marks on them.
My thinking is that I can get this entire setup for around 600 bucks. I have a 4 bolt main truck block in my garage. Its prob gonna cost me around 700-900 to get the machine work done on it. Since I know it needs bored and honed etc.
My thinking was this would possibly save a good ammount of money as far as machining etc. Please tell me if I am dreaming on this one.
If I built the short block out of this marine engine. Then bought the 062 heads and vortec intake what kind of cam should I run with the flattop pistons to keep the compression in the range where I can get away with 87 octane? Or would it be worth it for me to buy dish pistons?
Thanks for the input everyone.
05-04-2009, 08:24 AM
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Thats probably true. I am starting to actually to think I may be better off just having my block machined. I have purchased these 062 vortec heads machined for 550+ lift. What kind of CAm do you guys think i should run? And What kind of pistons should I get? Flat top or dish? Whats the best guess on HP rating?
Last edited by LURCHBIOTCH; 05-04-2009 at 08:45 PM.
05-05-2009, 12:12 AM
#16
if you do some reading over at chevy hiperformance and gm high tech, they have done countless 350 builds with all the various cam grinds out there, cylinder head combos, intakes, carb sizes, etc. the book "Small-Block Chevy Engine Buildups" by chevy high performance is $5 on amazon and worth it.
05-05-2009, 04:30 PM
#17
Camshaft wise you want something like the Comp Cams 12-206-2.
212/212 @.050 duration with .440/.440 lift on a 110 LSA. Would work just fine.
One step hotter would be the 12-210-2.
218/218 @ .050 and .454/.454 on a 110 LSA.
Run the vortecs with the pistons you already have and spend the money on higher octane gas instead of new pistons.
212/212 @.050 duration with .440/.440 lift on a 110 LSA. Would work just fine.
One step hotter would be the 12-210-2.
218/218 @ .050 and .454/.454 on a 110 LSA.
Run the vortecs with the pistons you already have and spend the money on higher octane gas instead of new pistons.
05-05-2009, 10:50 PM
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Camshaft wise you want something like the Comp Cams 12-206-2.
212/212 @.050 duration with .440/.440 lift on a 110 LSA. Would work just fine.
One step hotter would be the 12-210-2.
218/218 @ .050 and .454/.454 on a 110 LSA.
Run the vortecs with the pistons you already have and spend the money on higher octane gas instead of new pistons.
212/212 @.050 duration with .440/.440 lift on a 110 LSA. Would work just fine.
One step hotter would be the 12-210-2.
218/218 @ .050 and .454/.454 on a 110 LSA.
Run the vortecs with the pistons you already have and spend the money on higher octane gas instead of new pistons.
So I bought the 062 heads I spoke of in the third post. Whatever I decide to go with I will use them as my heads. I guess I could go higher octane gas or dish pistons or thicker head gasket(not sure about that one but someone suggested it to me)
But I got to thinking and I read some articles. I have come to the thinking of running a late 90's vortec block. Or any block that came with the stock hyd roller cam. I have read how most of these engines have less leaking issues and don't beat the sh*t outta the components so they at times require very little machine work to be overhauled. My thought is if I can find a decent one then I could rebuild it and upgrade to a new hyd roller cam and put my heads on it. What do you guys think about that? I am just not sure about the marine block to many unknown issues. (corrosion on the inside)
Again if I am outta my mind with my thinking please let me know
Thanks
Brian
