So my mustang has 154K miles on the engine and was wondering the pros and cons of just rebuilding my engine vs buying a new one.
302 Rebuild Vs. Buying a new engine
- Thread starter Paul Randle
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There really isn't any difference.
Likely the block you get will not be new.
The internals will depend on what you purchase.
The only real difference will be down time. To rebuild your engine will take weeks to months depending on your local machine shops.
Buying a crate engine may only take a few days.
154,000 is nothing on a well maintained 5.0.
Any particular reason you want to do a rebuild?
Likely the block you get will not be new.
The internals will depend on what you purchase.
The only real difference will be down time. To rebuild your engine will take weeks to months depending on your local machine shops.
Buying a crate engine may only take a few days.
154,000 is nothing on a well maintained 5.0.
Any particular reason you want to do a rebuild?
Depends?
Who will be rebuilding the engine? Joe blow in the back of his garage, or a well-trusted machine shop?
If oyu buy new, where is it coming from? A factory reman from Autozone, built by Joe Blow in the back of his garage or a well-trusted machine shop, or a DSS 331 stroker ?
Who will be rebuilding the engine? Joe blow in the back of his garage, or a well-trusted machine shop?
If oyu buy new, where is it coming from? A factory reman from Autozone, built by Joe Blow in the back of his garage or a well-trusted machine shop, or a DSS 331 stroker ?
ratio411
Founding Member
I'd rather do it myself.
Saves money and I know it is done like I want, no cutting corners.
However, I have the tools and space to do that.
If you don't have the tools, truck to haul parts to the machine shop, or decent size garage, that may not work for you.
Saves money and I know it is done like I want, no cutting corners.
However, I have the tools and space to do that.
If you don't have the tools, truck to haul parts to the machine shop, or decent size garage, that may not work for you.
65ShelbyClone
Founding Member
Well i am building up the upper end. Like heads, intake, cam n i am wondering if a stock bottom end will hold up to the different upper parts?
well the upper parts for a 302 work in a stroker? or will i have to change all the upper in? intake, heads, cam
65ShelbyClone
Founding Member
Yeah? A lot of guys on here are running stock bottom ends with modest and even massive top ends.
The stock bottom end will hold up to just about anything you throw at it, minus the limits of the stock block. You're not going to break it with a H/C/I upgrade, that's for sure.
...unless of course you buy a cam that's too agressive or a set of heads with really large valves and smash one into a piston.
Yeah I've heard you'll break the block before you ever break a stock crank, but I'm most certainly not going to test that theory lolThe stock bottom end will hold up to just about anything you throw at it, minus the limits of the stock block. You're not going to break it with a H/C/I upgrade, that's for sure.
...unless of course you buy a cam that's too agressive or a set of heads with really large valves and smash one into a piston.
Well this is the list i wanna do n i am hoping the stock bottom end will hold up fine
Gt40x heads
1.7 roller rockers
Trickflow Stage 1 cam
70mm throttle body
76mm Mass air meter
GT40 intake
24lb injectors
high pressure fuel pump
fuel regulator
So a stock bottom end will be fine with this set up right?
Gt40x heads
1.7 roller rockers
Trickflow Stage 1 cam
70mm throttle body
76mm Mass air meter
GT40 intake
24lb injectors
high pressure fuel pump
fuel regulator
So a stock bottom end will be fine with this set up right?
Assuming your engine is in decent mechanical condition (reasonable mileage, no excessive bearing wear, or worn rings, etc), you're a long, long way from breaking the bottom end with that set up.
If you have those parts or are getting a great deal on them, run em.
But If you don't, i would not buy the x heads new. I do really like them, but at their current price point NIB, the are not worth the money. If you are getting them used for $700 or less, they are a decent deal too, just not at over a grand.
A 76mm meter is likely a C&L, that's a piece of crap, get a pro m 95mm.
Skip the 1.7 rockers and go with 1.6's which will be stud mount if you go with better twisted wedge heads (which go on sale at summit from time to time for $999).
Then get a cam suited for 1.6 use.
But If you don't, i would not buy the x heads new. I do really like them, but at their current price point NIB, the are not worth the money. If you are getting them used for $700 or less, they are a decent deal too, just not at over a grand.
A 76mm meter is likely a C&L, that's a piece of crap, get a pro m 95mm.
Skip the 1.7 rockers and go with 1.6's which will be stud mount if you go with better twisted wedge heads (which go on sale at summit from time to time for $999).
Then get a cam suited for 1.6 use.
mikestang63
SN Certified Technician
x2 what 200xp said. AFR or TW heads are light years ahead of the X heads. For the cam, call Ed Curtis and have him grind you one. It will be the best money you ever spent. Or, if you want the cheapest match set that has proven to make good numbers, just buy the TW top end kit.
http://www.summitracing.com/parts/tfs-k514-360-350/overview/
You may want to go to 30'lbers and a matching MAF as the 24'bers although max out at about 350 hp, the prefered hp you should push them is about 325 NA. You can bump up the FP to compensate for the smaller injectors if you want to stay with 24lbers.
http://www.summitracing.com/parts/tfs-k514-360-350/overview/
You may want to go to 30'lbers and a matching MAF as the 24'bers although max out at about 350 hp, the prefered hp you should push them is about 325 NA. You can bump up the FP to compensate for the smaller injectors if you want to stay with 24lbers.
65ShelbyClone
Founding Member
24lb injectors may support ~350hp, but only at 100% duty cycle. When picking injectors, aim for ~85% max duty cycle, which puts 24lb squirters at ~300bhp assuming 0.55lb/hp-hr. Running them at 4 bar of pressure will net flow about like a 30lb injector, which will support ~370hp in the same conditions. It's better to have the larger injectors if you need them, though, than to run smaller ones at higher pressure.
There are two things that will break a stock shortblock: RPM and/or 500+ rwhp. Since boost wasn't in your build plan, the keeping revs under the stock rev limiter should make for a pretty reliable engine.
There are two things that will break a stock shortblock: RPM and/or 500+ rwhp. Since boost wasn't in your build plan, the keeping revs under the stock rev limiter should make for a pretty reliable engine.
Mehhh, they're better for certain, but I wouldn't say light years ahead. If you're jumping up to a higher class head, then horsepower figures are going to reflect that sure, but power flow figures and power making capability between out of the box TW 170's, AFR 165 and GT40X heads aren't all out game changing. On your average bolt on car, there's not generally more than about 20rwhp separating the three of them.
That horsepower can be made up in other areas and you’re going to pay for it regardless.
Basically, what I'm saying is....If I'm shooting for a particular horsepower goal and I know a set of GT40X heads will support the power levels with my combination of parts, I'm not going to shun them in favour of a set of Trick Flows or AFR's that I'll pay an additional $300-$400 for and have to scrap my current pedestal mounted valve train and convert to a stud set up for a few more ponies.
I thought about going to a set of AFR’s, or Trick Flow’s when I put my set up together, but chose the X’s for a few reasons. Number one was cost….big difference (at least in the used market). Two was the ability to use the stock style valve train. Three, there’s no question that when it comes to quality and bolt on, trouble free design, the Ford heads are your best bet. No worries about out of spec tolerances, casting flaws, inferior valve train components, etc. That to me was worth the few ponies I was giving up in trade.
Now….if I was going for higher power levels, then I would certainly have looked to a set of higher end heads like AFR 200/205’s, or TF FAC 190’s, or Track heats, etc. But for my goals, the GT40X’s did the trick.
That being said, I do like the Trick Flow top end kits. They’re quite comparable to most top end combinations…but kinda pricey. It just takes the guess work out of the ordeal for the novice….and looks pretty to boot.
