realistic motor build costs...

Kappa9012

MAN.... I Broke it again.
Aug 5, 2008
694
0
16
Peoria Il
Ok guys obviously with my mods on a stock bottom end I know my days are numbered and putting a motor together is going to be in my near future.

My question has two parts. first off, my current motor has 80k on it now, and seems to be in good working order so far, pistons and rods what other major work needs to be done to build a motor to reliably handle 8-900hp.

Studs the top and bottom, possibly a cam, what else?

2nd part of the question is I've seen some scary high #'s for rebuild cost and I'm really curious what goes into that. I have had several gassers done and machine work is no where near the cost of a diesel and i'm trying to understand why the super high costs. Not knocking anyone, but I just want to know what i'm paying for... besides gotta try and make up some shit to justify it to the wife....
 

OregonDMAX

NOT IN OREGON, NO DURAMAX
Apr 28, 2013
3,964
8
38
36
Goodyear, AZ
I would say the machine work cost is so high because not every machine shop has the equipment to handle duramax blocks. They are still a pretty new item compared to like a small block Chevy.

I asked my machinist that did all my SBC stuff over the years and he has never even touched a dmax and he's the best Chevy engine guy I've ever met.
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,667
5,813
113
Phoenix Az
Machining is not the most expensive part. Going to Guy at SoCal for all the machining you would need and balancing will cost you less than a set of rods.

All the machining, main studs, head studs, cut stock pistons, crower rods, new water pump tigged, all bearings and gaskets, magging the crank, and balancing everything plus having injectors checked, heads checked and machined cost me 5k. That's with Guy doing all my machine work. I saved quite a bit buying used parts but even with Brian buying all new, he wasn't far off of my 5k cause the machine shop he went to was half as much as guy
 

S Phinney

Active member
Aug 15, 2008
4,008
18
28
Quncy, Fl
You should be able to do machine work for 1500 area with a valve job depending on how many guides need replacing. If you are doing the wrenches yourself you would spend the area of 8-9k. This is a basic build with using pistons, rods, studs (head and main), new oil pump necessary machining etc. Cams, ported heads, girdles, etc run up the cost but do add to efficiency of the engine. Then you add injectors, turbos, duel pumps, etc and you get into some pretty hefty dollars. These are very real figures. You can always be the cheapest of guys but don't expect to be as durable or run as well. Careful planing and selection of parts and suppliers will benefit you more than any buddy discounts that you can stumble upon. Good luck with your build.:thumb:
 

SSchmi5519

LLY Cult Leader
Oct 19, 2008
3,387
1
36
Arizona
I would plan on 10k with seals and everything, plus you never know what you are going to find when you tear down. Would be a bummer to start the build and figure out you need new heads, pistons, etc and be out of money.

In the performance world you should be able to afford the part, and then afford it again when it breaks.
 

S Phinney

Active member
Aug 15, 2008
4,008
18
28
Quncy, Fl
I would plan on 10k with seals and everything, plus you never know what you are going to find when you tear down. Would be a bummer to start the build and figure out you need new heads, pistons, etc and be out of money.

In the performance world you should be able to afford the part, and then afford it again when it breaks.

And maybe a few more times on top of that!
 

blk smoke lb7

<-----Lots of green $
Nov 8, 2010
5,694
0
36
57
belvidere,ill
I have 12ish in mine.
2 head jobs and a new head dont count :spit:

Yeah no shit.........i dont even want to know what i have in mine total.


Contact Phiefers machine shop in Freeport ill he is a great guy and built my motor and built Jason wherlis motor also.Just buy all your parts your self,if he buys the parts he marks them up.Shoot me a pm awith your phone # and i will send you a text of my build sheets with prices............just dont tell me what the total is lol.I only had him do the short block and i installed the heads and everything else.If i can help in any way let me know.
 

Kappa9012

MAN.... I Broke it again.
Aug 5, 2008
694
0
16
Peoria Il
my buddy just got his motor back from phiefers as well, so I know they do good work. So from the sounds of it the bulk of the cost is still in the rods and pistons?

I should have prefaced with Short block. I know the injectors and turbos are already a very healthy chunk, The 480 I have is more than enough on the top end I would probably swap the stocker for a 366 or a big vvt under the 480.

So if I had the rods and pistons I'd be into the bottom end for a few grand? That seems a lot more realistic. For some reason I was thinking the machine work was going to be several thousand by itself...
 

THduramax

Will it ever end!
Aug 15, 2012
407
0
0
Flaherty, ky
I'm just finishing up a motor build... And my total for everything I did is about 14k... Luckily my buddy did all the wrenching so I don't have a labor cost.. If ya take away the dual fueler, overhauled 100% injectors, and turbo I believe the total would be around 10k.. But I did some extra things that really didn't need to be done like a diff intake runners, bridge etc. that was an extra grand or so.. Machine work was 2800 ( cut pistons, keyed, line bored, valve job, misc. replacement pieces inside, sb assembly, decked, balanced) don't spare anything inside motor. Of course rods, arp stuff is crazy $.. But needed.. Get a good known overhaul gasket kit.. I got the run around on a cheap one that was missing all kind if gaskets.. Weld water pump too(new) plan to spend a couple grand more than what u plan cause u never know what u gonna run into... Damn that was a long one.. Few freakin coffee
 

dmax711

New member
Mar 4, 2011
1,057
0
0
concord, north carolina
To give you an idea on price and labor machine shop wise mine was 60$ to key the cam, 60$ to key the crank, balance 250$, assembly of the shortblock 500$, headwork and valvesprings 1500$ and previously I had machine work done to the block for around 1200 which included main studs and a .20 bore ,decked, align honed, torque plate etc.. alot of machine shops say they can do it but take your time and find someone who HAS done a duramax, this is not something to rush or cheap out on.
 

Dirtymaxx03

Active member
Aug 4, 2009
3,109
1
38
FWIW i am in the middle of a fairly rowdy BBC build. Motor, trans, driveshaft, fuel system, all that good stuff. By the time i am done i will have built a whole play truck for less than what it costs to budget build a single dmax motor. And the BBC will be faster lol

Screw this diesel stuff. Maybe i will build one when i hit the lotto