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G-force
Joined: 05 Jul 2005 Posts: 105 Location: no-po, OREGON
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Posted: Thu Jul 07, 2005 6:09 pm Post subject: again engine trouble, grenaded, time to do it rite. help! |
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ok two motors died in two hours due to detonation. tired of this and running out of toys to sell. summers here need boat. i was thinking the first one bit it because head gasket was upside down, but now this again so its down to bad distributor, leaned out /weird carb(edelbrock 600) low fuel press (not likely since i changed to electric between blow ups) or ?
so heres the multi question: should i stay with SBC and if so how do i build a reliable 400 HP? i have two newer gen blocks, stock rods, no pistons, nodular crank, and iron big valve heads.
also i have no machinist because the one everyone says is good and expensive has my stuff, and they seem to know their chit, but the only guy who i found at a parts store that seems to know an engine from his ass said they are the last place he would take it. he also said some of his motors blow up after not very long, so i am lost without a light. can anyone recomend an engine builder in portland or am i just better off buying a crate and if so who has the best deal?
thanks -g
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JamesS
Joined: 05 Jul 2005 Posts: 90 Location: Calgary, Alberta, Canada
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Posted: Thu Jul 07, 2005 11:35 pm Post subject: |
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What kind of compression ratio were you running in your engines that blew up?
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G-force
Joined: 05 Jul 2005 Posts: 105 Location: no-po, OREGON
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Posted: Thu Jul 07, 2005 11:43 pm Post subject: |
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9.5
also i wish to use NOS on the next motor if that is safely possible. 75 or 100 shot
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Xerophobic
Joined: 23 Jun 2005 Posts: 970 Location: Calgary Alberta, Canada
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Posted: Fri Jul 08, 2005 5:31 am Post subject: |
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What exactly "blew up"? Your comp doesn't sound too crazy as long as your deck height etc is setup properly How big are the chambers? Was the timing right? What octane u running? If you don't have pistons now buy forged for sure. I greneded a whole set of hypereutectics!
Cheers
_________________ T-53 , why go up and down when you wanna go round and round???? |
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AR
Joined: 23 Jun 2005 Posts: 181 Location: Iowa, USA
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Posted: Fri Jul 08, 2005 6:28 am Post subject: |
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G-Man, You need to go back and read everything that was recommended before, it was all good advice.
If you don't have the skills or a trusted machine shop a crate would be the way to go, and you get WARRENTY !
Nitrous- 75/100 shot will work with a stock set-up, but if you lose fuel pressure you can still melt a motor. If you don't like to pay close attention to your motor all the time leave the Nitrous off and buy a Crate.
Try-Jegs, Summit, Chet Herbert, and your Chevy Dealer. If you buy a Ford then you'll need the Nitrous.
Any of the guys on this site that Race will give you good advice, they all run their motors wide open to the extreme for miles and miles and they live ! Most of the time...................
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Bald Man The Myth.... The Legend
Joined: 22 Jun 2005 Posts: 654 Location: Under the bridge
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Posted: Fri Jul 08, 2005 12:05 pm Post subject: |
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You'll never go wrong with a GM crate motor. ZZ383's or a ZZ4 are very dependable if you leave them alone.
I punished a ZZ4 for 3 / 4 years with 90% of the hours to pin.
Or you can pay 50K for this one.
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Aluminum Squirt
Joined: 15 Jun 2005 Posts: 46 Location: Sacto, CA
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Posted: Fri Jul 08, 2005 3:15 pm Post subject: |
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The ZZ383 is claiming 425HP at 5400RPM's and 460 ft/lbs at 4500 RPMs. Just under $4800 from Jegs. Looks promising. Got most of the right stuff for a small shot of N2O. A little pricey but probably less than somebody building 2 motors for you. Just a thought, I don't have any experience with it-Aluminum Squirt
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G-force
Joined: 05 Jul 2005 Posts: 105 Location: no-po, OREGON
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Posted: Fri Jul 08, 2005 6:03 pm Post subject: |
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yeah i would go back ad read except its uh,... gone. i am going to try the sbc one more time. i know its possible just wondering if its worth it. some say the 5.7" 383 is not as good as a 6" 383, but cheaper to build so most are 5.7. i am thinking of using my cast crank, and rods and using forged pistons. my machinist assures me hyperujunktics are good for 1000 hp so i shouldnt worry but?
also i have been running a rex thermostat housing with the bypass and 4 ports, using a 160 deg t-stat and the motor runs about 180. what are thoughts on this? am i better off without a t-stat?
also are there any clearances that should be different for a jetboat than a car engine?
thanks. hey baldy that motor would be fine. loan me 50k and i will make payments.
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JamesS
Joined: 05 Jul 2005 Posts: 90 Location: Calgary, Alberta, Canada
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Posted: Fri Jul 08, 2005 6:45 pm Post subject: |
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"Are there any clearances that should be different for a jetboat than a car engine?"
No, the clearances should be the same for both.
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Kev-o
Joined: 17 Jun 2005 Posts: 625 Location: Sylvan Lake
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Posted: Fri Jul 08, 2005 7:26 pm Post subject: |
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Bald Man. do tell of this motor, one of Rob`s?
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G-force
Joined: 05 Jul 2005 Posts: 105 Location: no-po, OREGON
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Posted: Fri Jul 08, 2005 8:43 pm Post subject: |
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Aluminum Squirt wrote: | The ZZ383 is claiming 425HP at 5400RPM's and 460 ft/lbs at 4500 RPMs. Just under $4800 from Jegs. Looks promising. Got most of the right stuff for a small shot of N2O. A little pricey but probably less than somebody building 2 motors for you. Just a thought, I don't have any experience with it-Aluminum Squirt |
some folks say 383 isnt a good idea for a jet, higher rpms for extended time makes them hurt a bit. one builder recommended a 355 or 377 de stroker for this app/
however it worked great on mine for the first season. why would you use one? it would be in between classes wouldnt it?
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G-force
Joined: 05 Jul 2005 Posts: 105 Location: no-po, OREGON
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Posted: Fri Jul 08, 2005 8:44 pm Post subject: |
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JamesS wrote: | "Are there any clearances that should be different for a jetboat than a car engine?"
No, the clearances should be the same for both. |
even if i run without t-stat and motor is always cold? what else happens to motors with this type of cooling?
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MaxPower
Joined: 09 Jul 2005 Posts: 48
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Posted: Sat Jul 09, 2005 8:32 am Post subject: |
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G-force, are you running without a t-stat? A motor has to have heat. If you use a heat exchanger you don't change clearances, if you don't use one the clearances are looser. Were you running premium(92) and how much total timing? Did the piston melt/scuff or break? If your machinist told you hypereush!ttics are good for 1000 hp that is your cue to get the hell out of there and never look back. Try to get alum. heads with your new engine, they resist detonation way better. 383's work awesome in boats. Like Xero, I have eight expensive ashtrays if you need one.
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Cavefish
Joined: 18 Jun 2005 Posts: 130 Location: Klamath, CA, USA
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Posted: Sat Jul 09, 2005 8:51 am Post subject: |
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A big aye on the crate motors- I have had great luck with them, only managed to kill them with bad cooling so far. The $2900 GM Performance parts partial block sounds expensive, but it's actually a great deal, they are put together right and they live. It does have Hyprooctalmagnafluoride pistons, but they will live. I would question them if I was going much beyond 400 hp.
There are a lot of ways to cool them but if you don't want to be a gauge slave, use a thermostat and some kind of circulating pump. Aluminum heads (L98 or fast burn) are a really good idea too. I am running Vortec heads now and pump gas, this is working out so far.
_________________ -Jesse |
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SouthIdahoGary
Joined: 15 Jun 2005 Posts: 295 Location: Wilder, ID, USA
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Posted: Sat Jul 09, 2005 9:50 am Post subject: |
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G-
A rambling of thoughts---
Sallee Chevrolet is within easy driving distance of Portland. No freight costs. They not only have all the GM crate motors, they use them for a basis of their own line of performance motors. They have people on site that you can talk to and motors ready to go. Lots of options. Might be worth a Saturday drive.
Several of the aluminum boat manufacturers offer a 383 as an OEM option. The "convential" aluminum boat users seem to be using them with success. The increased torque is a plus. However the longer stroke increases the piston speed at any given rpm. We have used 406 and 434 cubic inch small blocks in the Family Fishin' Boat and have had hundreds of hours on them. For making usable power there is no substitute for cubic inches. Small block vs big block weight savings are substantial.
Some of the crate motors (like the afore mentioned ZZ383) do not come with intakes or ignition. Sallee takes these and completes them. The ZZ383 uses the Fast Burn heads that require a raised runner intake manifold.
The ZZ4 comes complete except for a carburetor and plug wires. Depending on your starter configuration you may have to get a different flex/flywheel.
What exactly "blew up" (i.e. Pistons "broke" or melted, broken rod(s), seized bearings, bent valves, "stuck" piston in bore, spark plug firing ends melted / broken) and under what conditions? Breaking in? Full load? Idling in the driveway? Partial throttle cruise? In the water running the boat?
What is the ignition you are running and how is it hooked up? What kind of initial advance? Do you know what your total advance actually is at 3000 rpms? 4000 rpms? Do you run vacuum advance?
You list detonation damage as the killer. Detonation comes from improper ignition timing, too lean fuel mixture, wrong octane, any combination of the above.
_________________ "faster, Faster, FASTER until the thrill of speed overcomes the fear of DEATH"#163 "Tuff-n'-Nuff" |
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