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Trying to make 450hp
What gm head castings and valve sizes?
What cast iron intake? What cam? With 9.0-1 to 9.2-1 CR does it take to make 450hp with a .030 over 454 mark IV I will be running emi manifolds wet risers through hull. And a 800 Holley DP. Or is this possible? Just don't want to build a pig. I have the block/ rods/ crank ready to go. Just need to know what heads so I can order my pistons. Thanks Aaron |
Ill make it really easy for you. Engine masters just did a 454HO buildup for a marine app.
Stock 454 shortblock, 236/242* hyd roller cam, dart 310 aluminum pro 1 heads, dart single plane intake, holley 1000 hp 4150. Engine made 525HP@5600RPM, and kept pulling to 6000 making power. 517FT lbs at 4800. Only thing I might do different, is a little less cam duration, and a little more lift than the one they used. That should bring the peak HP down to around 5300-5400. |
"330 on roids" did 460hp @ 5200 for something a little milder/cheaper
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Originally Posted by MILD THUNDER
(Post 3509637)
Ill make it really easy for you. Engine masters just did a 454HO buildup for a marine app.
Stock 454 shortblock, 236/242* hyd roller cam, dart 310 aluminum pro 1 heads, dart single plane intake, holley 1000 hp 4150. Engine made 525HP@5600RPM, and kept pulling to 6000 making power. 517FT lbs at 4800. Only thing I might do different, is a little less cam duration, and a little more lift than the one they used. That should bring the peak HP down to around 5300-5400. |
Originally Posted by Artate78
(Post 3508265)
What gm head castings and valve sizes?
What cast iron intake? What cam? With 9.0-1 to 9.2-1 CR does it take to make 450hp with a .030 over 454 mark IV I will be running emi manifolds wet risers through hull. And a 800 Holley DP. Or is this possible? Just don't want to build a pig. I have the block/ rods/ crank ready to go. Just need to know what heads so I can order my pistons. Thanks Aaron |
Originally Posted by MILD THUNDER
(Post 3509637)
Ill make it really easy for you. Engine masters just did a 454HO buildup for a marine app.
Stock 454 shortblock, 236/242* hyd roller cam, dart 310 aluminum pro 1 heads, dart single plane intake, holley 1000 hp 4150. Engine made 525HP@5600RPM, and kept pulling to 6000 making power. 517FT lbs at 4800. Only thing I might do different, is a little less cam duration, and a little more lift than the one they used. That should bring the peak HP down to around 5300-5400. |
Originally Posted by mike tkach
(Post 3509663)
Aaron,gm sells a crate motor,i think it is 425 hp 454.go on the gm performance website and check it out,i think with the parts they are useing,and a little bit more cam,450 is easile achieved.
good option also http://www.chevyhiperformance.com/te...ine/index.html |
Wouldn't an old Merc 420 spec engine with a nice hydraulic roller cam get you in the ballpark or a little more?? You could still use the GM rectangle heads and save $2000 over going with aftermarket heads. If you were going after market heads I would also go with the Darts.
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Thanks for all the response guys. Only thing didn't want to run aluminum heads or intake. Salt water eats them up.
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Originally Posted by Artate78
(Post 3508265)
What gm head castings and valve sizes?
What cast iron intake? What cam? With 9.0-1 to 9.2-1 CR does it take to make 450hp with a .030 over 454 mark IV I will be running emi manifolds wet risers through hull. And a 800 Holley DP. Or is this possible? Just don't want to build a pig. I have the block/ rods/ crank ready to go. Just need to know what heads so I can order my pistons. Thanks Aaron .30 over 454 (365 mag origin) Dart 308's Comp XM-270h-12 cam AirGap intake HP 500 Carb IMCO EXHAUST MANIFOLDS 453 HP @ 5500 505 TQ @ 4300 |
Originally Posted by Artate78
(Post 3509947)
Thanks for all the response guys. Only thing didn't want to run aluminum heads or intake. Salt water eats them up.
As for cast iron intake, well, good luck performance wise. You could try to hunt down an older marine aluminum intake that has bronze liners or simply find someone to hard anodize an aluminum intake for you. I can verify that it makes them 'electrically dead' as I've had to run a ground to the coolant temp sensor to make the sensor work. LOL. |
Wow I've never heard of that. What is all involved in that process?
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you dont need aftermarket heads or anywhere near that compression to make your goals.
my Gen IV 454 MAG stock bore, stock crank, stock pistons, stock heads (rect port OEM '90 454 MAG heads with no mods other than rebuilding them) with air gap intake an 850 carb and mild custom roller cam made 470+hp@5200rpm. cam wasnt anything crazy since i have silent choice with short risers so the cam specs had to be relatively tame to prevent reversion. i also have my OEM 454 MAG aluminum highrise intake with the brass liner in it that i would sell if your interested for your build. good luck! |
Is the intake dual plain? If so how much
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Originally Posted by gsxr1216
(Post 3510046)
you dont need aftermarket heads or anywhere near that compression to make your goals.
my Gen IV 454 MAG stock bore, stock crank, stock pistons, stock heads (rect port OEM '90 454 MAG heads with no mods other than rebuilding them) with air gap intake an 850 carb and mild custom roller cam made 470+hp@5200rpm. cam wasnt anything crazy since i have silent choice with short risers so the cam specs had to be relatively tame to prevent reversion. i also have my OEM 454 MAG aluminum highrise intake with the brass liner in it that i would sell if your interested for your build. good luck! For me, with Iron heads I'd keep it somewhere around 9:1. Aluminum heads, I'd go 9.5-10:1. If you think you'd put a blower on it down the road, aluminum heads and 9:1 max. |
Originally Posted by Artate78
(Post 3510071)
Is the intake dual plain? If so how much
Yes it is. $150 i guess?? |
I am having problems getting my new build to spin high rpms, my cam guy is telling me to get rid of the 3/8 fuel supply and go bigger, the max rpm i got out of it was 5000, im running 781 heads but the smaller valves and a bob m cam with .6 lift, with air gap intake, 750 holly, small dome pistons. , 462 ci. Any ideas
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I bought the boat off the Internet only looking at pics. Freshly built 468 500hp 70 mph boat. Guy seamed honest we talked back forth for cupple weeks. So we made the deal big mistake. Got the boat straight to launch. fired it up Pulled off idled out. Went to give some gas no power. Back to launch pulled dip stick water in oil. Man I was sick. So go to fix head gaskets pull heads. Three shattered melted pistons. Then I was really sick. So here I am.
Block was no good so got new block But every thing else is good Gm big ovals 290 heads full roller rockers 219/188 valves Comp cam .505/.515 .262/.268 112 lsa Part# 11-232-3 Gm oval port intake part#3854100 Holley 800 DP Machine sHop said he could work the heads a little and get them to flow to 48 to 4900 rpms. Witch the cam stops at 5000 All this stuff is like new was a fresh build he just blew it up then passed it on to my dumd ass So my question is how much hp would a .030 over 454 9 to 1 ish make with all the parts listed |
Man thats hard to say from what ive read 420 hp, mine should be a 450 hp motor but im chasing this fuel idea now to see if i can pull the 5300 rpm the cam is rated for.. sorry to hear, Ive heard good things about the 290 heads, maybe my 781 with smaller valves are my limiter in power. What cc are the 290 heads
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Originally Posted by pantera232
(Post 3510138)
im running 781 heads but the smaller valves and a bob m cam with .6 lift, with air gap intake, 750 holly, small dome pistons. , 462 ci. Any ideas
Long time ago has a mild 9:1 454 small hyd cam street car than ran 12.80's with stock 781's. Put on Merlin Oval Ports (bigger valves 2.19/1.88) with nothing else and dropped to 12.20's and gained bunch of mph. Anyhow, stock small valve oval ports don't do much in the power department. We run bigger valves in 'street' SBC's than you have in your heads. Edit in: of course I can't answer on your tunin nor rigging (which kill many boats performance) without taking a 'look see' of what you have going on. Can tell you, as i did, those heads are killing airflow ie: power. |
The 290 heads are 100.1 cc closed chamber. Would I do better with 049 or 781 with open chamber with 219/188 valves
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What is your idea on this 3/8 fuel line should i go up to 7/18 or 1/2 inch ? BOB is telln me im not getn the fuel, im running a 23 mirage and getting 4800 rpm on a 24 pantera wot
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well the lower cc heads are higher compression, my 781 were cc'd around 114 but we only did 2 of them, what size valves are in ur heads.
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If you have water in ur oil u probly have reversion and need to extend your inner pipes
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Pantera232 your heads or only good for around 4500 rpms your heads or running out of air
And for the water in the oil had 3 pistons with about 1" holes in them would that make a vacuum that would pull the water from the exhaust it had stock manifolds My valves or 219/188 |
Originally Posted by Artate78
(Post 3510024)
Wow I've never heard of that. What is all involved in that process?
Unlike the regular process of sulfuric acid anodizing, hard anodizing involves a special electrolysis process that creates a thick layer of aluminum oxide both on and in the surface. This process protects metals and alloys from deterioration, which is why depending on the application it is intended for, this process is preferred. The sulfuric method of anodizing involves a vat of sulfuric acid that a metal is dipped into while an electrical current is being sent through the vat. The combination of the acid bath and the electrical current is what changes the body chemistry of the metal. Hard anodizing simply cools the acid to the temperature of freezing water and significantly increases the electrical current running through the acid. This process is usually utilized with aluminum. The process is easier then using regular anodizing treatments on tougher metals, and also costs less and produces a metal that is tough but lightweight. Hard anodizing allows the positive characteristics of aluminum to be utilized. These include low density, exceptional thermal conductivity and electrical resistance, and good pliability. Hard anodizing is preferred by many industries, for a variety of applications. The automotive industry often uses the process to create internal car parts that will be non-conductive and heat resistant. Cookware used by industrial food processing plants or bakeries are often hard anodized, again because of the thickness and strength that is its trademark. Also Teflon, which is a non-stick element popular in cookware, adheres to hard anodized metal better then it does to others. Because blood can be so corrosive of metal parts, the medical field commonly uses products put through the hard anodization process for its prosthetic joints and limbs. Another reason this type of metal is preferred is because of its appearance. Hard anodized aluminum is less porous then aluminum anodized by sulfuric acid. Therefore aesthetically it is a smoother and sleeker end product that is more pleasing to the eye. The colors can not be as bright and vibrant though, because the pore size of the surface will not support them. Therefore, dark brown and black shades are most common, although darker shades of other colors can also be created. |
If you suspect running out of fuel, your spark plugs should tell the story.
Running these stock gm truck heads, your just not gonna make the power. A 454 is small enough by todays standards. To make power, you NEED to spin the engines. 4800, 4900, 5000 just ain't gonna do it. Build them with cams, heads, intakes, and carbs that will support 5600-5800 and let them run. There is an abundance of cams, lifters, valvesprings, rockers, etc, that can support the additional rpm with no problems. Not that many options 25 years ago, so guys tried to make low rpm power reliably with oval ports truck heads, dual planes, etc. |
Pantera232 if it was your fuel line it would run good till it sucked bowls dry then fall on face not do it the hole time
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Originally Posted by Artate78
(Post 3510143)
I bought the boat off the Internet only looking at pics. Freshly built 468 500hp 70 mph boat. Guy seamed honest we talked back forth for cupple weeks. So we made the deal big mistake. Got the boat straight to launch. fired it up Pulled off idled out. Went to give some gas no power. Back to launch pulled dip stick water in oil. Man I was sick. So go to fix head gaskets pull heads. Three shattered melted pistons. Then I was really sick. So here I am.
Block was no good so got new block But every thing else is good Gm big ovals 290 heads full roller rockers 219/188 valves Comp cam .505/.515 .262/.268 112 lsa Part# 11-232-3 Gm oval port intake part#3854100 Holley 800 DP Machine sHop said he could work the heads a little and get them to flow to 48 to 4900 rpms. Witch the cam stops at 5000 All this stuff is like new was a fresh build he just blew it up then passed it on to my dumd ass So my question is how much hp would a .030 over 454 9 to 1 ish make with all the parts listed |
No he said it was a good strong runner. What goes around comes around
Guys name is Scott Welker he lives in hot springs arkansas he is a real peace of **** hasn't answerd a phone call or returned any Tex sense this deal he got me good |
Originally Posted by pantera232
(Post 3510163)
What is your idea on this 3/8 fuel line should i go up to 7/18 or 1/2 inch ? BOB is telln me im not getn the fuel, im running a 23 mirage and getting 4800 rpm on a 24 pantera wot
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Originally Posted by Artate78
(Post 3509947)
Thanks for all the response guys. Only thing didn't want to run aluminum heads or intake. Salt water eats them up.
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Originally Posted by MILD THUNDER
(Post 3510205)
If you suspect running out of fuel, your spark plugs should tell the story.
Running these stock gm truck heads, your just not gonna make the power. A 454 is small enough by todays standards. To make power, you NEED to spin the engines. 4800, 4900, 5000 just ain't gonna do it. Build them with cams, heads, intakes, and carbs that will support 5600-5800 and let them run. There is an abundance of cams, lifters, valvesprings, rockers, etc, that can support the additional rpm with no problems. Not that many options 25 years ago, so guys tried to make low rpm power reliably with oval ports truck heads, dual planes, etc. At this point over the winter i could either have the head shop do the larger valves or find some merlin,dart heads and install all the guts. |
Pantera, just curious what fuel pump are you running. You should at least be running something like this.
http://www.summitracing.com/parts/HLY-712-454-11/ |
Jim, it's a fuel pump run of belt, and attached to water pump, I also have a old electric one that I can switch
On at helm when doing high speed runs, is there a certain electric pump i should run. |
Originally Posted by pantera232
(Post 3510970)
Jim, it's a fuel pump run of belt, and attached to water pump, I also have a old electric one that I can switch
On at helm when doing high speed runs, is there a certain electric pump i should run. |
Can't see any specs running 7psi at idle, its a gen 6 block it's a nice setup if water pump breaks, I'm going to open up the tank next week and check pickup
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Originally Posted by picklenjim
(Post 3511021)
I couldn't tell ya anything about the electric pumps.Never messed with them. Those pumps that run off the water pump, is there anything special about them or will any BB pump work. Have any idea of the specs of the pump that's on there now.
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Originally Posted by pantera232
(Post 3510163)
What is your idea on this 3/8 fuel line should i go up to 7/18 or 1/2 inch ? BOB is telln me im not getn the fuel, im running a 23 mirage and getting 4800 rpm on a 24 pantera wot
I run Mallory 140GPH electric fuel pumps. |
I'm running 7psi at idle I'm going to
Run it tomarrow and see at wot, prop is a 23 plus I also have a 23 mirage fastest prop For boat so far. |
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