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Mmmm....781 Heads w/Big Valves - Greg72's 496BBC Build Thread

Latest Updates......MORE PARTS!!!

OK All,

Thanks for being patient. These things take a while, but I finally got to the point in the build process where "you pay your money and you take your chances"!!! :D I ordered to complete rotating assembly yesterday for this 496 build.

I'll tell you what I know, and Scott can fill in the details.

The parts vendor was Powerhouse (shop.enginekits.com)

I decided to go with forged components instead of cast....I know this was supposed to be a "budget" build, but everything I've read and everyone I've spoken to says that the forged components are a lot stronger and worth the extra "piece of mind"....so I made the stretch with the $$$.

Parts Ordered:

4340 Forged Crank w/ chamfered bearings
4340 H-Beam Rods
New Balancer
SFI-Approved Flexplate upgrade (yes, this means some sort of slushbox gets used)
.060" Flat Top Forged Pistons w/ Two Valve reliefs 8.4:1 @ 118cc
Pre-Gapped Rings
Complete Balance of Rotating Assembly


A couple of interesting points about the parts.....the guy I spoke with at Powerhouse mentioned that the H-beam rods (although stronger than the standard I-beams) would actually require LESS clearancing to work....a good thing! The flat top pistons that were selected seem like a poor, low-compression choice (vs. a domed one) but since my final head volume is going to be 115cc, the compression will actually bump up to the 9:1 mark, which is just about perfect for this iron-headed buildup.

Total price for all components (including shipping) came to $1839.00.... not too bad considering that I elected to make some substantial "upgrades" to forged components. :deal:

Parts delivery will take about 7 - 10 days since everything needs to be balanced before shipping out, but that will give Scott time to get the heads pressure tested and get the block cleaned and prepped for it's machining (bore, deck & square)



:usaflag:
 
Greg,
I'm very pleased with the NV4500 in my tow rig. I want one for the k5 now.
It shifts very smooth compared to the sm465, and the 5th gear is just awsome. I averaged 10-11 mpg round trip towing to moab and back.
The swap can be done for under $2K if you get everything at a decent price.
I got the NV4500 for $750, about $400 for the round pattern np205, 300 for the bellhousing, a couple hundred for the clutch and a couple hundred for the hydro setup.

PS. I have my old hyd. roller sitting in my garage.. Punch these numbers in your desktop dyno and lets see what that 496 is estimated to make.. :wink1:
Advertised duration: 284 / 294
Duration @ .050: 238 / 248
Valve Lift: .578"/ .608"
LSA: 108
 
oh i know.
that cam i threw out there is probably nowhere near ideal and a bit mismatched to the combo since the 496 will be relatively low compression..
i was just curious to see what desktop dyno says as far as how much top end HP you'd gain and how much low end TQ you'd be sacrificing by going with a big cam...
 
I see, you will need all the opening and closing numbers to be accurate.
 
Those 781 heads are pretty nice when you put the bigger valves in. I was looking for a set of 049 or 781 heads for my K30 but I think I might go with the Edelbrocks again.

I love the way they come out of the box:
port_thumb.jpg


I'm going to try and use the same combo that Edelbrock used and hopefully end up with similar numbers as their dyno.

bbcheads.jpg
 
Latest update.....as of today 2007.05.18 (Friday)

PowerHouse is probably NOT where anyone else should be buying their parts from. There were a few problems with my order and I'll probably end up eating a few dollars by having to replace the flexplate and balancer with new items. Also due to those swaps, the balance job that I paid them $285 to complete is invalid, and I'll have to pay to have everything rebalanced with the new components.

Beyond that, I placed another order through Summit for a whole host of new ARP fasteners, and the retrofit roller cam kit.

Scott has gotten the block prepped at this point (bored, decked, etc) and clearanced for the longer 4.25" stroke. The crank wouldn't balance properly so it ended up in a CNC lathe last night and had approximately .248" removed from the counterweights to get it back into the ballpark. Scott assures me that there's still plenty of "meat" on the webs and it's going to spin like a jewel.... :thumb:

No new photos yet, but Scott is taking them. I'll post up when they arrive.



:usaflag:
 
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I guess that's why I needed to clearance the crank!!!!
 
Aint it fun buying chinese cranks:doah:. My last one came out of the box bent .004 and needing to be polished. When my crank guy got done with it and fitting the rods I need to run .001 undersize bearings....deep sigh
George
 
smalltruckbigcid said:
Aint it fun buying chinese cranks:doah:. My last one came out of the box bent .004 and needing to be polished. When my crank guy got done with it and fitting the rods I need to run .001 undersize bearings....deep sigh
George
Click to expand...

I don't think the crank was bent....it was just really heavy and wouldn't balance even after drilling out quite a bit of weight. The shop decided that it would make more sense to do some CNC work on it to get the weight closer overall, and then do the fine tuning with the conventional drilling.

Anyway, I guess I'm just another person who can laugh when I hear the words "budget stroker" in a discussion. The "budget" part of that expression has already left the building for this project.

All I can say now is this engine better absolutely RIP once it's installed.... :deal:
 
Is this crank internal or external balance? Stock rods or longer ones?
 
Good looking build man! Cant wait to see/hear this thing run:D
 
that would make about a thousand of us who are waiting.
Cool man.
 
Oxymoronic sayings that roll easily off the tongue, happily married, military intelligence and budget stroker come easily to mind.

I've only had one budget stroker motor that was cheap to put together. A water cooled VW I put together to run for a week. SO of course it ran for 6 months as I beat the hell out of it stoplight racing.
 
I could've swore there were some people watching this build thread. :confused:

Recent pics up for 5 days now and not a single reply. :crazy:
 
4X4HIGH said:
I could've swore there were some people watching this build thread. :confused:

Recent pics up for 5 days now and not a single reply. :crazy:
Click to expand...
Oh, I'm watching :D

(Note for the outsiders: Scott has been kind and patient enough to take on my basket case 454, with the same heads and valve work, but with a stock crank, i.e. not a stroker.)

And Scott, the rest of us are at once drooling over the motor, and angry at Greg being lucky/crazy enough to build it :)

-- A
 
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Aaron, i think i now have all your parts with the exception of the rings. :thumb:
 
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