SoCal Jet Boats
Tech Talk => Engine Mechanical / Electrical => Topic started by: Reefmoto on January 20, 2016, 09:29:30 PM
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I have a 454 that I am boring .030 over, It is going in a 21' commander with a jet. I will be running stock heads( they will be decked and match ported, they are ☆ peanut port ) and it is a gen 5 block. I need a rotating assembly and have found a bunch online. I have heard to pick my parts but in my case I think a " kit" would be best. what are your thoughts on the skip white kit?
http://www.ebay.com/itm/BBC-454-SCAT-ROTATING-ASSEMBLY-WISECO-FLAT-TOP-FORGED-PISTONS-454-FT-4-280-2pc-/331596930716?_trksid=p2141725.m3641.l6368 (http://www.ebay.com/itm/BBC-454-SCAT-ROTATING-ASSEMBLY-WISECO-FLAT-TOP-FORGED-PISTONS-454-FT-4-280-2pc-/331596930716?_trksid=p2141725.m3641.l6368)
this seems like its the best bang for my buck, I was also looking at the summit racing
http://www.summitracing.com/parts/sca-1-92249 (http://www.summitracing.com/parts/sca-1-92249)
thoughts? i know ring gap and being able to hold high RPM is key for a jet boat motor and i think these kits would be best for my application
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Those flat-top pistons with be around 8:1 compression ratio. If you are building a naturally aspirated engine, I would consider 9.5:1 to be the minimum compression ratio. The larger the cam, the more aggravated this situation will become.
Could you please list some other information about your boating and performance goals?
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Family boat, want to run on pump gas. Not trying to race want it to be reliable. If I can go 50 mph great, I want somthing That'll last. noticed that the skip white is for a 2 piece main,my block is single. I want to stay N/A and have about 3k to play with
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...noticed that the skip white is for a 2 piece main,my block is single...
There are adapters to run an earlier 2-piece seal style crankshaft in a later 1-piece seal style block.
http://m.summitracing.com/parts/stf-7035
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I have a 454 that I am boring .030 over, It is going in a 21' commander with a jet. I will be running stock heads( they will be decked and match ported, they are rectangular) and it is a gen 5 block. I need a rotating assembly and have found a bunch online. I have heard to pick my parts but in my case I think a " kit" would be best. what are your thoughts on the skip white kit?
http://www.ebay.com/itm/BBC-454-SCAT-ROTATING-ASSEMBLY-WISECO-FLAT-TOP-FORGED-PISTONS-454-FT-4-280-2pc-/331596930716?_trksid=p2141725.m3641.l6368 (http://www.ebay.com/itm/BBC-454-SCAT-ROTATING-ASSEMBLY-WISECO-FLAT-TOP-FORGED-PISTONS-454-FT-4-280-2pc-/331596930716?_trksid=p2141725.m3641.l6368)
this seems like its the best bang for my buck, I was also looking at the summit racing
http://www.summitracing.com/parts/sca-1-92249 (http://www.summitracing.com/parts/sca-1-92249)
thoughts? i know ring gap and being able to hold high RPM is key for a jet boat motor and i think these kits would be best for my application
If you are going a 'kit' anyways, why not stroke it?
489 kit from summit, for a 1 pc rear main: http://www.summitracing.com/parts/sca-1-91755/overview/make/chevrolet (http://www.summitracing.com/parts/sca-1-91755/overview/make/chevrolet)
Keep your rpms @ 5K or less, and run a big impeller, like a 'AA', great out-of the-hole, and cruise rpms are lower, vs an 'A' impelller.
Choose your cam wisely, being a gen V, a factory style roller would be a nice addition.
This cam in a 9:1 454 (460 in) pulled a 'AA' to 5K, ~500 hp, in a heavy azz Eliminator Daycruiser (thru logs and snails)
http://www.summitracing.com/parts/hrs-cl120245-12/overview/make/chevrolet (http://www.summitracing.com/parts/hrs-cl120245-12/overview/make/chevrolet)
A decent intake will help the combo, I'm using a Eddy Victor Jr single plane intake, and a 750 Holley VS.
Thats all I got
Dan'l
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If you are going a 'kit' anyways, why not stroke it?
489 kit from summit, for a 1 pc rear main: http://www.summitracing.com/parts/sca-1-91755/overview/make/chevrolet (http://www.summitracing.com/parts/sca-1-91755/overview/make/chevrolet)
Keep your rpms @ 5K or less, and run a big impeller, like a 'AA', great out-of the-hole, and cruise rpms are lower, vs an 'A' impelller.
Choose your cam wisely, being a gen V, a factory style roller would be a nice addition.
This cam in a 9:1 454 (460 in) pulled a 'AA' to 5K, ~500 hp, in a heavy azz Eliminator Daycruiser (thru logs and snails)
http://www.summitracing.com/parts/hrs-cl120245-12/overview/make/chevrolet (http://www.summitracing.com/parts/hrs-cl120245-12/overview/make/chevrolet)
A decent intake will help the combo, I'm using a Eddy Victor Jr single plane intake, and a 750 Holley VS.
Thats all I got
Dan'l
I have a holley 800 an edelbrock performer RPM q-jet 7164 intake manifold What are the thoughts on this intake mani? came on the motor with the boat, I also have BARR marine CHVA 192 headers for it. I am looking into my pump after I finish engine. I planned on putting an inducer on it to help with getting motor up and running.
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7164 is a oval port manifold- and you stated you have rectangle port heads, a bit of a mismatch there??? Pics and casting #'s would help.
I prefer single planes on jet boat motors. But have seen many dual planes on 'em too...
I had a eddy carb on mine for the weekend, while the holley was being rebuilt, and lost ~200 rpm.
But then again a Vacuum secondary Holley 3310 shouldn't work on a jet boat, either...IDK???
What impeller do you have now, and what RPM will it pull?
Dan'l
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7164 is a oval port manifold- and you stated you have rectangle port heads, a bit of a mismatch there??? Pics and casting #'s would help.
I prefer single planes on jet boat motors. But have seen many dual planes on 'em too...
I had a eddy carb on mine for the weekend, while the holley was being rebuilt, and lost ~200 rpm.
But then again a Vacuum secondary Holley 3310 shouldn't work on a jet boat, either...IDK???
What impeller do you have now, and what RPM will it pull?
Dan'l
I'll look at it when i get home, heads are at machine shop so I'll have to dig through disassembly photos
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7164 is a oval port manifold- and you stated you have rectangle port heads, a bit of a mismatch there???
I prefer single planes on jet boat motors. But have seen many dual planes on 'em too...
I had a eddy carb on mine for the weekend, while the holley was being rebuilt, and lost ~200 rpm.
But then again a Vacuum secondary Holley 3310 shouldn't work on a jet boat, either...IDK???
What impeller do you have now, and what RPM will it pull?
Dan'l
Heads are 10114156, and the holley is a 9022-1030... I think I'm good to go on that. I think the previous owner just tossed a car motor in and ran it as such. I'll have to find out how to tell what impeller I have after some research. I know it said TD on the jet
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i noticed that the intake mani doesnt match the carb though
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I believe the 156 heads are the vortec 454 peanut port heads if I'm not mistaken, would have come out of a truck..
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I believe the 156 heads are the vortec 454 peanut port heads if I'm not mistaken, would have come out of a truck..
My first jet boat 454 had these heads, and was an Indmar Marine 400 hp 454, with 156 heads, installed in 1996.
I still have the heads, cast iron intake, and the 'owners manual' for the motor.
And yes, peanut port heads, huge chambers, too
Dan'l
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just found some complete 049 with covers for 300 bucks, good deal? take offs he states...
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I dont think 300's outrageous as long as they just need to be freshened up.. obviously you dont want to find out they're cracked when you take them to shop... 049's are good ovals..
Your Friendly local v-drive owner
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You have to use a specific head gasket tho putting mark4 heads on a gen5 block, i dont remember the # of the felpro we used on matches909's 502, but maybe he'll chime in if he still has our parts list for his engine..
Your Friendly local v-drive owner
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just found some complete 049 with covers for 300 bucks, good deal? take offs he states...
This guy is on the site chime in tell me about the heads?
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I have a 454 that I am boring .030 over, It is going in a 21' commander with a jet. I will be running stock heads( they will be decked and match ported, they are ☆ peanut port ) and it is a gen 5 block. I need a rotating assembly and have found a bunch online. I have heard to pick my parts but in my case I think a " kit" would be best. what are your thoughts on the skip white kit?
http://www.ebay.com/itm/BBC-454-SCAT-ROTATING-ASSEMBLY-WISECO-FLAT-TOP-FORGED-PISTONS-454-FT-4-280-2pc-/331596930716?_trksid=p2141725.m3641.l6368 (http://www.ebay.com/itm/BBC-454-SCAT-ROTATING-ASSEMBLY-WISECO-FLAT-TOP-FORGED-PISTONS-454-FT-4-280-2pc-/331596930716?_trksid=p2141725.m3641.l6368)
this seems like its the best bang for my buck, I was also looking at the summit racing
http://www.summitracing.com/parts/sca-1-92249 (http://www.summitracing.com/parts/sca-1-92249)
thoughts? i know ring gap and being able to hold high RPM is key for a jet boat motor and i think these kits would be best for my application
If you are on a budget, and not looking for big power, why not a used GM crank? Then maybe some aftermarket I beam rods with cap screws instead of stock through bolt 3/8" GM rods, and forged pistons, get them all balanced with damper and flexpate and good to go. You would be better off spending the money saved on some better heads, the peanut ports are going to hurt your power output.
I have been considering putting together a "budget" stroker build, with an aftermarket cast crank. Why spend the money for a new cast crank and not increase displacement?
Ring gap is important in any engine, you can't go tighter than recommended minimum gaps, slightly looser (as in non-file fit rings) won't kill you. Bearing clearance is more critical and needs to be measured rather than assuming that if the crank turns it will be fine.
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I will get you a part number tomorrow for those gasket numbers
Sent by a Sleekcraft SST owner on the SoCal Jet boat app
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Thanks for all the input! right now I am going to reuse my stock crank/rods, and peanut ports are out. I am going to be purchasing a set of nice forged pistons this week and will hopefully have some new heads this week as well. I found a pair of 1256 2934, but need to do more research on them. they came off a running 7.4 but dont know if they would be worth it or should i just find some 049's
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I strongly encourage you to get your static compression ratio well into the high 9's with your quench distance at .045 (gasket thickness). It will easily be pump gas friendly and will operate more efficiently with better power and economy.
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Thanks for all the input! right now I am going to reuse my stock crank/rods, and peanut ports are out. I am going to be purchasing a set of nice forged pistons this week and will hopefully have some new heads this week as well. I found a pair of 1256 2934, but need to do more research on them. they came off a running 7.4 but dont know if they would be worth it or should i just find some 049's
The 2934 head is a 502 rectangular port head. Likely you will do better for a non-race jet boat with oval port heads, if you plan to make moderate power and run in the 5000 rpm range. The rectangular port heads are better suited to higher rpm or larger cubic inches, or both.
As I said before, if you were going to spend any money on new bolts and resizing your stock rods, it makes more sense to just buy a set of Eagle or Scat I beam rods that use a 7/16" capscrew.
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I strongly encourage you to get your static compression ratio well into the high 9's with your quench distance at .045 (gasket thickness). It will easily be pump gas friendly and will operate more efficiently with better power and economy.
I'm shooting for 9 to to 1
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I'm shooting for 9 to to 1
9.5 to 1 is still ok with iron heads. My advice is to make a firm decision on which heads you are using prior to purchasing pistons, so you can calculate compression ratio. You won't have an exact deck height measurement without having a shop measure and tell you, or actually mocking up the assembly in the block with one piston and rod, but can probably get close. If you want some help figuring out compression ratio, there are various calculators online, or ones you can download.
Once you have heads and decide on which pistons to buy, while the assembly is being balanced you can start thinking about camshaft, but not before you know all the parameters of the engine you are building.
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Yep waiting on price for the marine 502 heads, they are bone stock heads straight from the factory/machine shop ready to go (will go to machine shop to be measured). Waiting for price, what do you guys think?
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Yep waiting on price for the marine 502 heads, they are bone stock heads straight from the factory/machine shop ready to go (will go to machine shop to be measured). Waiting for price, what do you guys think?
See my comment above, the 049's are honestly probably better for a jet boat engine.
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See my comment above, the 049's are honestly probably better for a jet boat engine.
Ok I'll see if I can source any closer than Santa clarita...should have just bought a 502 to begin with
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Ok I'll see if I can source any closer than Santa clarita...should have just bought a 502 to begin with
That's still an option!
You will get the most return parting out your existing engine parts.
Good luck,
Joe
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Well decided to buy new dart cast heads, also bought some forged dome top pistons, forged rods and bought a forged 4"stroke crank. Didn't want to do a stroker crank because I would have to do more machine work. Now I'm searching for thru transom tubular header, and a eddlebrok Victor intake mani single plane. Only thing I'm keeping is carb and possibly headers... cam is to be determined once I decide on headers.
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Well decided to buy new dart cast heads, also bought some forged dome top pistons and bought a forged 4"stroke crank. Didn't want to do a stroker crank because I would have to do more machine work. Now I'm searching for thru transom tubular header, and a eddlebrok Victor intake mani single plane.
Arg, wish you would have checked with me first, most GM 4 bolt blocks have enough clearance for a 4.250" stroke crank with H beam rods, no problem. Once you are buying new stuff, cost is the same, but you gain cubic inches.
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Arg, wish you would have checked with me first, most GM 4 bolt blocks have enough clearance for a 4.250" stroke crank with H beam rods, no problem. Once you are buying new stuff, cost is the same, but you gain cubic inches.
Really, not to late... but at the same time I'm getting a smoking deal on a forged 4"crank ($200)
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Really, not to late... but at the same time I'm getting a smoking deal on a forged 4"crank ($200)
OK, that's a good deal, but as I said, I put lots of them together, only one I had to do some grinding on was a 2 bolt block.
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OK, that's a good deal, but as I said, I put lots of them together, only one I had to do some grinding on was a 2 bolt block.
I'll look into stroker crank, but it's hard to pass up a 200 dollar forged crank... maybe I'll throw some nitrous on it to make up for non stroker
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I'll look into stroker crank, but it's hard to pass up a 200 dollar forged crank... maybe I'll throw some nitrous on it to make up for non stroker
All things being equal, on a pump gas engine you may only see about 40 HP difference for the difference in cubic inches.
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I'll look into stroker crank, but it's hard to pass up a 200 dollar forged crank... maybe I'll throw some nitrous on it to make up for non stroker
What crankshaft is it? Are the journals standard or undersized? Are they polished and ready to run?
Reason I ask is, you could probably turn a little profit to help finance your build.
Then throw the nitrous at it!
Good luck
Joe
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Well decided to buy new dart cast heads, also bought some forged dome top pistons, forged rods and bought a forged 4"stroke crank. Didn't want to do a stroker crank because I would have to do more machine work. Now I'm searching for thru transom tubular header, and a eddlebrok Victor intake mani single plane. Only thing I'm keeping is carb and possibly headers... cam is to be determined once I decide on headers.
Sounds like a nice build. I do hope you are not holding it back by limiting compression.
Too much compression and you have high operating expenses or risk rattling it to death. But it is no fun driving low compression pig.
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What crankshaft is it? Are the journals standard or undersized? Are they polished and ready to run?
Reason I ask is, you could probably turn a little profit to help finance your build.
Then throw the nitrous at it!
Good luck
Joe
I have good help now, eagle crank needs polish... I'm selling everything else, stock pistons and rods, stock cast crank that has been turned and ready to go, peanut port heads and my eddlebrok qjet rpm intake mani
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I have good help now, eagle crank needs polish... I'm selling everything else, stock pistons and rods, stock cast crank that has been turned and ready to go, peanut port heads and my eddlebrok qjet rpm intake mani
Hit me with a pm with a list of what you got and what you want for it.
Thanks.
GT
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Do we have any pictures posted?
Shawn