Motor - rebuild or buy?

B

bolsen

dont know jack, but trying
So, I was thinking; what is the cost to benefit ratio of a rebuild vs. fully built crate? Basically, would it be more or less cost efficient to rebuild my stock block with the best possible pistons, rods, crank, cams, cylinder heads, etc. (to get it ready for S/C) or buy a crate from somewhere like Fox Lake or SHM, etc.? I plan on doing one or the other within the next five years or so and just want to really get the though process rolling. Any discussion is welcome and appreciated. Also, I will most likely pull the motor myself and work on it over the course of a few weeks/months.
 
What are your ultimate goals for the car? Is it going to be primarily street driven, or run mostly on the track?

What's your HP target?

Do you plan on running NOS? How much boost?

What's your budget?

If you're going to stay south of 500 RWHP and run primarily as a street car, a stock block and for that matter, stock internals will prolly do.

You wanna push big HP and run juice, better look at a built motor, and that can get expensive. Ask Sherm, Marty-O, Marauder TJA, fordnut, and a couple other guys what they've got invested, and I'll bet the number is well up into 5 figures.

Lots of things to consider that go into the decision matrix, best bet is to get those defined first and then start some comparative analysis.
 
Well, street driven "hot rod" that will see track time. I want this car forever and see no reason to EVER sell it, so the stock motor will not last my whole life, especially with boost. I intend on hitting the around the 500rwhp mark. I enjoy driving it, so I would never take off the road and only race it. If I wanted a drag car I'd spend ahlf the money and build a crap-stang to go twice as fast. I want the Hot Rod version that should've been provided by Ford in the first place. Basically, I want power and longevity. I don't want to say "money is no option" because it is, but I will have around 20k to build or buy. However, I would like my 20k to go as far as possible.
 
No Nitrous for me...EVER. I'm interested in the KB Mammoth blower upgrade designed for the 03-04 Cobra.
 
Might want to consider going with a Cobra block as an alternative.

PM DOOM and CWright to get some insight into their builds, Doomie's running a Cobra block, and I think Chris is running either a big Whipple or a KB on top.
 
I dunno. I've always thought of long block internals as pretty scary. It's the materials science part of it. Totally feasible to choose parts and bolt them together. Hard to predict exactly how much a piston or a rod or a head or whatever will expand or contract, or the subtle effects over time. That's just heat and cold. Start changing things around (even unintentionally) and factors like tensile strength, minor changes arm length, crank sweep, valve angle. You can just overbuild everything, but that doesn't help with stuff like heat dissipation, manufacturing tolerances, assumptions made with cooling and oiling passages, etc. An engine isn't just a pile of parts, it is a system.

Eventually I want to go aluminator, but I plan to enjoy this engine while I build out the car to tolerate it. When I've done everything else around the engine then it may be time to swap in the final part. That way I'm ready to swap with a minimum of expense and downtime when it's time.

That's my plan and useless .02.
 
That makes sense. I wouldn't just go buying parts willy-nilly; I would discuss parts and choices with various shops around the country to come to come to good understanding of what parts would compliment eachother the best. Otherwise, you're right, it could seriously through off the mechanics (no pun intended) of the motor.
 
I hope I didn't come off as preachy or arrogant. I feel just just the opposite. Kinda like doom when he answers every question with 'Motorcraft.' :)

I don't think I'm up to it. But you may be. :bows::beer:
 
SC Cheesehead said:
You wanna push big HP and run juice, better look at a built motor, and that can get expensive. Ask Sherm, Marty-O, Marauder TJA, fordnut, and a couple other guys what they've got invested, and I'll bet the number is well up into 5 figures.

Lots of things to consider that go into the decision matrix, best bet is to get those defined first and then start some comparative analysis.
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Easy 5 figures, by the time you figure the cost of a blower, headers, cams, etc. parts.

Then there is the labor, are you going to install it yourself? You will have dyno time involved as well.

For the record, mine is street driven(rarely though), 521RWHP,526TQ, safe tune, 13k for the long block (stroker) & installation & tuning, 7 or 8k for the twin screw, 1.5k or so for headers & cats.There were some other misc. parts needed, bigger injectors, MAF, cams & springs, fuel pumps, flexplate and so forth.

20k is eaten up pretty quick, can't wait to hear what your decision is.
 
Spectragod said:
Easy 5 figures, by the time you figure the cost of a blower, headers, cams, etc. parts.

Then there is the labor, are you going to install it yourself? You will have dyno time involved as well.

For the record, mine is street driven(rarely though), 521RWHP,526TQ, safe tune, 13k for the long block (stroker) & installation & tuning, 7 or 8k for the twin screw, 1.5k or so for headers & cats.There were some other misc. parts needed, bigger injectors, MAF, cams & springs, fuel pumps, flexplate and so forth.

20k is eaten up pretty quick, can't wait to hear what your decision is.
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Yes costs add up for a fully built motor when you go with any kind of stroker, boss50, heads, cams setup easily at $13-15k. Ive got 11k just in built 324ci motor using my heads, 3k in trans and another 1k in exhaust another 1500 in supporting mods, MAF, injectors, FP without labor.....However 20K for built motor and blower is doable. I vote FRPP Aluminator high compression LB and SC with install be about 16-17k.
 
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Look into MMR as well. I just got mine running today from them, I did supply all parts.

I can tell you where NOT to go.
 
Mike M said:
Look into MMR as well. I just got mine running today from them, I did supply all parts.

I can tell you where NOT to go.
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MMR has a full range motors to suit your needs. I went with the stroker mod 900s (supports 900rwhp) with the BOSS50 option and other goodies. Thus far have about 15k miles on it and avg 300-315 miles mixed city/hwy. my advice call 3-4 builders let them know what you want and go from there. Research and have a budget is a good idea.
 
Just get a Alluminator LB from Tousley Ford! It is a proven LB. Thats what I got and with a safe tune 545/556 all day long. Or just get U a reman 03-04 Termi LB 3500-4000 ish and either one will handle 650ish no problem. I say this cause unless you get a big wallet this is the best bet. Cause like others mentioned you go with a custom build + all the stuff needed for a Twin screw build youre gonna be in for over 20k it's reality & good possibility more then car cost ya.
 
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