Building 427 shortblock
Derrick
Derrick
I would not build your own short block for the cost savings alone, I would do it mainly for the experience. If you are NOT interested in the experience and knowledge, then any savings you might experience from building it yourself will be offset by having an engine that was not from a major builder (MTI, LPE, LME, etc.) READ LOWER RESALE
I am going to do a 410 CID iron block this winter and I will do a full detail build how-to. I expect to pay more than a crate engine because of all the tools (bore gage) and everything else, but I am hoping to capitalize on the knowledge
dave
dave
There is no resleeving with an iron block as long as you do not go beyond a 4.06 bore ...a 4.04 is sitting right next to me..
The Best of Corvette for Corvette Enthusiasts
Block $2999 (speed inc. 2399 + 600 core)
Diamond piston set $586
Diamond piston rings $180
Lunati forged rods $690
Eagle forged crank $990
Bearings $70
Total - $5515 plus machine work (about $500)
So, I'm still trying to figure out why an assembled shortblock is so much more. I must be missing something in this equation. I already have all the other parts for this build (AFR 225cc Heads, Comp Cams Cam, Kooks 1-7/8" headers, A&A supercharger kit, and the other stock parts from the LS6).
Also, Lunati's 427 stroker kit is about $3800. Why? The individual parts are only $2500. Geez, nothing seems to make sense here.
Just looking to see if I'm out to lunch here on thinking this is right.
Thanks,
Derrick
The machine work is a little more than you may expect, since they should also balance the rotating assembly, line hone the crank bore and cam bore, check head and pan surfaces, magnaflux the iron parts, clean out the threads, and double-check all the clearances that you already checked. In my case the machine shop recommended tighter stock clearance bearings instead of what I ordered since my crank wasn't worn at all.
Also you're missing the studs, gasket kit, timing chain, camshaft, oil pump, and lifters that are usually included, that's at least $1,000 there. My big regret in building my forged motor is that I didn't coat anything. I should've got coated pistons (low-friction coating on the skirt and thermal coating on the pistons), thermal coated cylinder chambers and ports, and coated bearings (probably another $750). Diamond pistons are rated to 15psi max boost, I brought mine to 17psi and toasted them, a thermal coating would have been insurance against that.
A little more research, and I would've found that top ring space is very important with boost, since the top ring land is the weak point on a piston. The bigger the space, the stronger the ring land, but you increase the gas volume (change the CR) and unburned gas. There are custom pistons for turbo applications, for example Mahle makes coated turbo pistons which are good for high boost applications, these are different pistons than the standard LS1 Mahle forged coated pistons.
There's also the expertise. I talked to Ross pistons today about max boost rating of their pistons, and their tech calculated compression ratio beyond what their online calculator does. He accounted for things I didn't think consider, the volume of the top ring land space and the actual gasket bore, not just thickness (gasket bore isn't cylinder size). The same kind of expertise would be found in an engine builder. Experience builds intuition, which is knowing something but not always being able to explain it.
Last edited by blu00rdstr; Sep 20, 2005 at 02:49 AM.
Good luck with the 427 project.
Mark
Randy
Forged Piston Upgrade Kit - LS1/LS6 5.7L
Upgrade your stock short block with a new set of Speed-Pro forged pistons, Sealed-Power moly rings, Clevite77 bearings, and a new set of high performance rod bolts from ARP for your stock rods.
1. Forged Flat Top w/2VR, 3.897” or 3.906” Bore Sizes (stock pin dia. 0.944”)*
2. Sealed Power Moly Ring Set (1.5/1.5/3.0mm)
3. ARP HP 8740 Steel Rod Bolts
4. Clevite 77 Bearings (specify - std, .010, or .020 sizes)
#KITSD32621FS 3.898” - Stock Bore Piston Kit $599.95
#KITSD32621F25 3.906” – Piston Kit $599.95
Forged Piston and Ring Combo - LS1/LS6 5.7L
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Connecting Rods and Crankshafts
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LS1/LS6/LS2 Connecting Rods
Scat I-Beam
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Scat H-Beam
H-Beam rods are designed to provide extra strength for high HP applications and added insurance when required; these Scat rods are good for upto 800hp!
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Comp-Star H-Beam
Attention to detail and extra machine work make the Comp-Star a proven performer for H-Beam rods. This rod is used by top quality machine shops across the USA.
3. 4340 Steel H-beam Design, 6.125” Length, 0.927” Floating Pin
4. Light Weight Design, Approximately 615g
#CSC6125DS2A2AH GEN3&4 6.125” H-Beam, 0.927” Pin $569.00/set
Lunati Pro-Mod I-Beam
Made in the USA! Bad boy I-Beam rod for serious horsepower applications up to 900hp! Aircraft quality 4340 steel and 7/16” ARP bolts are just a few of the upgrades for the Pro-Mod rod from Lunati to provide the extra strength needed for race applications.
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Manley Billet Light Weight I-Beam Rods
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MAN14359-8 GEN3&4 6.125” Billet Rod, 0.927” Pin $1069.00/set
Forged Pistons
We stock a large supply of performance forged pistons for the LS1 and LS2 style engines. From naturally aspirated combinations to low-compression twin turbo setups, we have the pistons you are looking for.
Speed-Pro 346ci Forged Piston
Easy forged upgrade for your stock 5.7L, premium forged alloy and coated skirts are standard features for this LS1 piston. Call for any tech info you might need.
1. For Stock Stroke(3.622”) and Stock Rod Length(6.098”)
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L2621F 3.898” Bore 5.7L Forged Piston F/T 2VR $52.75ea
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Large Dish 402ci for Blower/Turbo Applications
1. For 4.000” Stroke, 6.125” Rod, 1.117”CH, & 4.005” Bore
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4. 0.927” X 2.250” HD Pins
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I think I'm probably going with the C5R block. But your Lunati Pro series crank/rods deal looks interesting. I was leaning a little toward the Callies crank too. Is there much difference? Also, can the JE pistons come coated? I'm looking for 9.0-9.2:1 compression to run about 12-15 psi of boost (I ran 20 psi in my GN with 8.7:1). How long are these deals going for? I'm afraid to buy anything right now because I'm moving in mid October, and afraid things will get lost in shipping (In the Navy and I don't yet know my new address). Any military discounts???
Thanks,
Derrick
Oh, do you have a web site? I can't find it, but I'm pretty slow..
I think I'm probably going with the C5R block. But your Lunati Pro series crank/rods deal looks interesting. I was leaning a little toward the Callies crank too. Is there much difference? Also, can the JE pistons come coated? I'm looking for 9.0-9.2:1 compression to run about 12-15 psi of boost (I ran 20 psi in my GN with 8.7:1). How long are these deals going for? I'm afraid to buy anything right now because I'm moving in mid October, and afraid things will get lost in shipping (In the Navy and I don't yet know my new address). Any military discounts???
Thanks,
Derrick
Oh, do you have a web site? I can't find it, but I'm pretty slow..












