Opinions on motor build

ZeroGravity58

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Mar 23, 2008
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Just asking for opinions on how you would set this up. Have a rotating assembly already. Durastar crank, carillo rods, mahle race cast. Power goal is 850-950 street/combo. Currently have a billet 68mm 4094vgt in the valley under a billet s480 with race cover, 100 overs, 10mm pump. As of now going to reuse my block as it only has 54k on it, stock mains with girdle, socal 3388 cam, stock heads with springs/pushrods, single 12mm with 150-200 overs. Turbo setup??? Unsure to re use what I have or change the atmo to a s483/s485 or run a single s472 or s475. This is mostly a street truck but will make it to the track a few times a year. Will also go on vacation with the family so I don't want a completely laggy smokey truck. Never will tow with it. Hit me with what you have....
 

LBZ

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Jul 2, 2007
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I’d leave everything the way you have it now. Maybe upgrade the heads to at least a stage 1 SoCal with heavier springs or something similar and an AF cam. If you run out of fuel you can always upgrade to a 12mm or twin pump it later. Obviously studs everywhere, a fresh water pump - welded if you’re planning on running high rpm’s, keyed crank and cam should already be there with the new crank and SoCal cam. Maybe consider upgrading the oil cooler to an L5P.

Twins make towing much nicer and better driveability IMO but depending on elevation you can make a big single work. My buddy runs a 483/471 combo with 100 overs, twin sportsman’s and made just under 900 all motor and over 1000 on spray. No issues with rail pressure on the dyno or the street. It drives good but he’s never towed with it. You’re looking for a little less hp so I’d think you would be good.

Once you get a solid shortblock the external bolt on stuff is minor to change later on.
 

ZeroGravity58

Well-known member
Mar 23, 2008
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I was thinking the same thing. I thought about changing the pump while it is apart then worry about everything else after it is together. Injectors and turbo setups arnt hard to change
 

Bdsankey

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Feb 1, 2018
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I don't see why your current turbo and injectors wouldn't meet your goals. The only thing that I would change now is the injection pump by either adding a second pump or by going to a 12mm+ pump.


Eventually you could step up to a 485 on the atmospheric and pick up some power.
 

Dozerboy

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Jun 23, 2009
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I think you have a good plan. I would stick with your 100overs if you happy with them. I agree the pump is the only thing holding you back. Next will be the 480.
 

Chevy1925

don't know sh!t about IFS
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Oct 21, 2009
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as others have stated, looks like a pretty good setup. that 150-200% injector range would be good for that power range. the 68 with a 483 or 85 will easily get that power and not be super smokey. If you dont mind changing the converter and running a single like the 475 or 480, id build the top end to run rpm. So better flowing heads, more cam, valve springs and pushrods so you can run up in the 4500-5k range and use all of the single. If you keep the twins, you can get around that with your current list at the top. you dont HAVE to have what im talking about for a single but it certainly helps the turbo light faster and keep the power going
 

ZeroGravity58

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Mar 23, 2008
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Sounds like all you guys agree that it's not a bad setup. Would you have the main caps doweled or does it matter if I run a girdle? So far I have a complete rotating assembly and picked up a set of socal valve springs. I'm going to keep collecting parts as I find them forsale and pull it apart in the fall. What flexplate/damper would you run? I'm not opposed to duel fuelers but last time I ran them I always had a lot of belt problems. I love the sound of a big single but I should probably stick with the twins, I just had the trans refreshed with a new Goerend R and it only has about 100 miles on it. Making up to say 1k power can I get by with arp 425 studs or do I need the 625's? Billet hold downs??? I'll probably get arp rocker studs also. I've never build a motor shooting for this kind of power.
 

Chevy1925

don't know sh!t about IFS
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Oct 21, 2009
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Sounds like all you guys agree that it's not a bad setup. Would you have the main caps doweled or does it matter if I run a girdle? Thats up to you but in my opinion, its not needed for the power. So far I have a complete rotating assembly and picked up a set of socal valve springs. I'm going to keep collecting parts as I find them forsale and pull it apart in the fall. What flexplate/damper would you run? BD is fine but nothing wrong with a socal one either I'm not opposed to duel fuelers but last time I ran them I always had a lot of belt problems. I love the sound of a big single but I should probably stick with the twins, I just had the trans refreshed with a new Goerend R and it only has about 100 miles on it. Making up to say 1k power can I get by with arp 425 studs or do I need the 625's? the 2000's should be fine but it depeneds on what kind of drive pressure you are going to see. if you want piece of mind, id either o-ring the block or heads and keep the 2000's or just run the 625's. Billet hold downs??? Yes I'll probably get arp rocker studs also. thats up to you once again, proper install and torque of the stock studs will be just fine. you need a ton of spring pressure and rpm to upset the stock bolts. id rather invest in lighter valvetrain first. I've never build a motor shooting for this kind of power.

posted in the quote above in red
 

ZeroGravity58

Well-known member
Mar 23, 2008
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Want to bump this back up, I pretty much have all my parts. Bought a socal flywheel, Ati balancer, have the crank, rods, pistons. Picked up a dualfueler setup with a stock lbz pump and a set of 200 over injectors. Also picked up billet hold downs. I'm down to finding a good used stock bore block, buying the girldle and picking up a cam. I changed my power goals alittle, I'd like to try and touch the 1000hp mark. Don't want to go much over as I don't want to be pulling motor and trans all the time. Just a goal to hit 4 digits. What cam? Anyone willing to ship me a good block that doesn't need an overbore. My race cast or standard bore.
 

juddski88

Freedom Diesel
Jul 1, 2008
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Chesterfield, Mass.
Want to bump this back up, I pretty much have all my parts. Bought a socal flywheel, Ati balancer, have the crank, rods, pistons. Picked up a dualfueler setup with a stock lbz pump and a set of 200 over injectors. Also picked up billet hold downs. I'm down to finding a good used stock bore block, buying the girldle and picking up a cam. I changed my power goals alittle, I'd like to try and touch the 1000hp mark. Don't want to go much over as I don't want to be pulling motor and trans all the time. Just a goal to hit 4 digits. What cam? Anyone willing to ship me a good block that doesn't need an overbore. My race cast or standard bore.

I have an extra RTA stock bore lmm block just out of the machine shop. $1500.
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,681
5,833
113
Phoenix Az
Want to bump this back up, I pretty much have all my parts. Bought a socal flywheel, Ati balancer, have the crank, rods, pistons. Picked up a dualfueler setup with a stock lbz pump and a set of 200 over injectors. Also picked up billet hold downs. I'm down to finding a good used stock bore block, buying the girldle and picking up a cam. I changed my power goals alittle, I'd like to try and touch the 1000hp mark. Don't want to go much over as I don't want to be pulling motor and trans all the time. Just a goal to hit 4 digits. What cam? Anyone willing to ship me a good block that doesn't need an overbore. My race cast or standard bore.
expect oil consumption and some blow by if you want a machined stock bore block that is not new from the factory. piston to wall clearance will high for cast pistons and will cause these problems.
 

Bdsankey

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Feb 1, 2018
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expect oil consumption and some blow by if you want a machined stock bore block that is not new from the factory. piston to wall clearance will high for cast pistons and will cause these problems.
^This was my worry as well. New/virgin blocks are getting pretty hard to find.
 

ZeroGravity58

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Mar 23, 2008
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Never thought of that...I know dmaxstore sells new blocks if they are still available. Juddski was the block just honed? How much clearance are we talking? Don't really want to swap pistons this assembly is already balanced
 
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KyleC4

Tech
Dec 30, 2016
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Bay Area
I believe dmax store lists the blocks part number that GM had in their performance catalog. And as far as I know when I last checked that block is not available. Unless dmax store bought some units when it was available
 

juddski88

Freedom Diesel
Jul 1, 2008
4,656
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Chesterfield, Mass.
Never thought of that...I know dmaxstore sells new blocks if they are still available. Juddski was the block just honed? How much clearance are we talking? Don't really want to swap pistons this assembly is already balanced

Block was washed, magnafluxed, mains checked for wear and alignment, decks cleaned up, and torque plate honed to use a std bore mahle cast piston. They did very minimal work to it, I'll get you some bore measurements if you're seriously interested in it.
 

ZeroGravity58

Well-known member
Mar 23, 2008
1,401
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Maryland
Block was washed, magnafluxed, mains checked for wear and alignment, decks cleaned up, and torque plate honed to use a std bore mahle cast piston. They did very minimal work to it, I'll get you some bore measurements if you're seriously interested in it.
Yes I am, I want to take and have my short block assembled and ready to go. Im going to run a girdle with stock caps, I'd only have to have the caps machined and lined honed to finish.