Engine swap or rebuilt - opinions

Looking for fellow owner opinions on this one -

My car has lower rod knock and will need a full rebuild. Where I live (upstate NY) has no reputable shops that work on fords, especially not the 4.6 32v, any engine shop I've called doesn't want to touch it or doesn't return my calls.

When I purchased the car it had similar issues. I had a family friend who is no longer practicing do the rebuild back in 05'. So, its already been rebuilt once and bored 20 over, the crank was machined as well.. so I am not sure that it can be rebuilt again anyway and certainly don't want to pay someone to pull it apart just to find that out. (opinions on this?)

I came across a mustang shop in Dover PA who has the same year (97) cobra motor for sale for a good price ($2500) and 50k miles on it coming out of his customer's car. I called the owner and he seems like a straight shooter - he agreed to do the work for 800, keep my old block, and swap over my existing mods. I'd ship it to him and have it shipped back. (I have no means for a truck or trailer and u-haul seems equal to shipping costs, plus I have no PTO left to drive down there during business hours)

So here's my question - should I fork over the 4k+ for a rebuild on an engine that has already been rebuilt once before, not knowing it if it may need more costly work after, or should I spend around 4k to get a motor I know works?

My cons seems to be that the serial numbers won't match and it'll devalue the car.. but I have no intentions to sell it and if I did, I wouldn't be getting top dollar anyway.

The pros seem to be the same exact engine with far less miles, a clean swap, and a guaranteed cost versus a climbing cost depending on the work needing to be done.

Just want the weigh in from other owners here - thanks.

I'd go for the rebuild. You know what you got at that point. With a used motor you don't know what you have got

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jgt58 said:

I'd go for the rebuild. You know what you got at that point. With a used motor you don't know what you have got

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Do you think the previous machining will be an issue? This seems to be a divided topic based on those who I've talked to. Unfortunately I don't have the money to "just open it and find out" like others have suggested.

I guess it's half dozen one way or the other. Your rolling the dice either way

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See if your straight shooter will provide any warranty on the pulled motor.

Tillerman77 said:

See if your straight shooter will provide any warranty on the pulled motor.

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That's very true

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Work with what you have and you will know what it is. Buying a used motor is a gamble-it could be a gem or a science project. After 20 years, I would think you are in for head gaskets at a minimum and replacing all the other seals in the oil cooler and coolant system will be warranted regardless of mileage.

The good news is that these cars really have no serial number matching to worry about. Keep the old block if it helps you sleep at night.

You can get another Teksid block for peanuts. Everyone seems to have moved on to the Coyote engine and demand has gone down. Blocks from a Mark VII are pretty easy to come by.

Take the stock replacement block to a machine shop along with your already oversided pistons and have the replacement block machined to them. Make sure the machine shop is familiar with working on aluminum blocks and uses a torque plate druing the work. Have the block decked. Get a fresh valve job on your Cobra heads and reuse them. You can upgrade the cams if your budget allows, although using the stockers will be fine. The biggest thisng to do is degree the cams no matter which direction you go. The crank should be fine. Spend the money to replace the oil cooler seals, IMRC seals and all the other ones while the motor is apart.

Good luck.

The other factor for the OP is how much faith he has with the shop doing the machining/rebuilding if he were to go with rebuilding his engine. With the wrong shop, it is possible to bleed a lot of $$ with little or no joy at the end of the project.
Regarding swapping the used 50K engine from another Cobra, besides checking on any warranty on the engine, you could also ask for a compression check and/or a leak down test on the engine. Another possibility is to ask for referrals for your strait shooter. Or ask to talk to his customer, whose engine you are considering, to see what he says about its condition.

All valid points on the used engine, I'll call and ask them today. Anyone have experience with Bill Fox's mustangs out of Dover PA? That's the place who's selling the engine.

I spoke with an engine shop here that would do it for around 4k. They have experience with that motor and feel confident in the work - problem is they won't pull the motor or reinstall, so I have to have another shop do that at an $1,100 cost.

So the rebuild is looking significantly more expensive.

Just called the shop, talked to the owner again who said:

"Its a 52k engine out of a car that took a passengers side front end hit, we make sure the engines run well before we sell them"

I asked about a compression check which they don't do. I asked what the warranty on the motor would be - he said 90 days. The previous owner just cruised in it. Basically he feels that since the engine only has 52k miles on it and came out of a stock car that it should be fine. *shrug*

If the general consensus is to just rebuild the thing then that's what I'll do. There's a lot of knowledge and experience on these boards that I've followed over the years so I trust the opinions here. Plus, I really just have no experience buying used motors.

Also here's the shop my friend referred me to - out of Rochester NY I guess

http://twautomotiveandmachine.com/

If anyone's got any experience with them.. They seem legit, hell of a lot closer.

Taco_Crisma said:

So the rebuild is looking significantly more expensive.

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Depends on how you look at it.
If you buy the used motor, and shit goes wrong, you need to do it all over again.