There are different kits. If you notice, that kit has 8 different applications, there is no part number and the prices are listed as "from". So when you order that kit, you go down a list with them and tell them application and desire. Then they will select the parts that fit. A stroker kit does not change bore.
What is your end goal? Why are you so dead set on the 3.7? Is it the extra displacement? You can get a 3.5L block for $250. Complete motor for $1500. With your talk about going for bigger power and possibly bending a 3.5 rod, are you thinking that a 3.7 rod (motor that factory has 60hp and 100ftlb less power) has stronger rods? If your planning to do a motor build, I would get the 3.5 block that you know will work and do the bore/stroke to it rather then trying to start with a 3.7 that may or may not work and still needing to beef up components. Starting with a 3.7, your pistons are not going to be designed for the 3.5 combustion chamber and need replaced (a set from Super Six is gonna be $1000+). Seems like a lot of extra work that will only result in needing to spend more money.
For premise, I think it would be cool if it is possible, they use the same rods and different pistons, but from what I can find all 3.7 engines use the same pistons and the mustang engines are making good power so if it’s feasible why not entertain the idea?
the stroker kit does change bore I spoke to super six the only way to achieve 4.0 l with that block deck height is with bore it is a 3.780 bore, you would run into rod geometry issues and clearance issues with the bottom of the bore and I’m sure other areas if you did not.
I am currently verifying this but there will be a max stroke length that these blocks are capable of running regardless, and to achieve the 4.0 l displacement you would have to bore the cylinder to make up for this.
If you read their pdf file they offer “.004-.020” oversized pistons and the crank is a 3.60 crank which according to their catalog is the only one they use in this application so the only difference they offer is rod length and piston height that would be dependent on the application, so you would have to bore the 3.5 out to atleast the bore diameter of the 3.7 to even come close the displacement with their crank only is 3.6 l with the 3.7 l bore size it’s 3.9 and some change so do you see where I’m going with this ? If you had a 3.7 block already you could just drop in the 4l crank rods and pistons to achieve 4.0l
As you stated before the bore on the 3.7 is around .100 larger but they use the same stroke crank shaft stock.
With that being said the crank shaft would have to be 7mm longer or .276” longer to use the 3.5 bore diameter which is not a little amount, if the 3.7l bore diameter was used (or larger) this stroke length could be decreased to reduce rod to stroke ratio which would lessen the strain on the crankshaft and rods due to piston velocity, stroke promotes larger torque numbers because of the velocity the piston is moving at, which is not what this application needs, these engines produce great torque as it is and could potentially produce more horsepower up top with a larger bore, even if you gained 40hp and shifted the torque curve higher it would be theoretically easier on the drivetrain
You cannot determine displacement by stroke length alone. Almost all stroker engines are either bored or less displacement and for this kit to achieve 4.0 l on the 3.5 it will have to be bored.
I also talked to multiple mls gasket manufacturers and they will make a custom gasket for this application, so if that’s the case 3.7 l engine are very cheap. And a easy way to gain displacement so if you’re already building a engine you can mitigate machining cost by having a larger bore diameter from the get go, it’s never been done on the platform so why not maybe more some people would be interested if they knew all of the information available about these engines,
I understand that the trans and ptu are a weak link, so if the work is already done and the possibility is there why wouldn’t someone want to start with the 3.7 block for a radically built ecoboost if you are gonna change rods and piston in the ecoboost why not in the 3.7 .2 l sounds trivial but with the 4l stuff they’re seeing almost 70hp from .5l increase so the slight displacement change may be beneficial.
@M.J make sure you are getting the correct engine if you are looking at explorer engines they switched to TI-VCT sometime within the production of those cars, you need to verify if your car has one cam phaser on the intake and one on the exhaust if it does, this is a TI-vct variant
If it is like mine, single phaser and solenoid you can tell by looking towards the front of the valve cover and the material the valve cover is made of I am unsure if they made shos with tivct but I do know they made explorers with it which I would suspect they do make them I believe 2016+ 3.5eb are tivct
I believe
Plastic -tivct
Aluminum -ivct
This is very important due to the harness compatibility
Also not everyone can get those engines that cheap, where I live they are 2500+ engines with 180k on them which is not at all worth it, unless the engine was catastrophically damaged it would be a better investment to rebuild it. Or source a low mile 3.7 at that point, which is why this idea was brought up, automotix and other junkyard distributors like lqk want a lot of money for the 3.5 eb engines and local junk yards do too. So that’s not probable for everyone.
The mustang pistons hold up to is why wouldn’t the other 3.7l engines especially if you put ring gap in them, people have been boosting na engines for eons now and I don’t forsee this being any different. Like I stated earlier if you’re going as far as building a dedicated engine for this platform why wouldn’t it be a good idea to just increase the Displacement for free essentially especially if you don’t wanna shell out the extra for a stroker kit if the displacement is already there why not? Nobody can tell me why it won’t work it’s all speculation there’s no evidence that it wouldn’t work.
I don’t like Speculation if there’s a will there’s a way and if the info is out there maybe more people will understand the platform and not be left in the dark on cheaper options for their build
If I rebuild my engine say it is a rod knock, that’s all of the rod bearings being replaced and sending the crank out to be inspected for possible heat checking and scoring on the crank with all that money I spent on getting the 3.5 back up I could have bought a 3.7 short block and bolted my heads up to the thing with cometics 95mm bore gen 1 eco boost head gasket
Hopefully this makes sense on why I wanted to entertain this swap, the only thing I am unsure of is if the tivct and ivct blocks are the exact same from what I’ve seen yes they are, but I know for a fact the ivct variations are identical because they are “gen1” I do not know if the block changed when they went to the updated version.
If I continue with the swap I will log everything on this site and keep everyone posted I think this swap could potentially help progress the platform even though some might think .2l is not that much difference
*displacements between engines*
3.5l
Bore: 92.5mm
Stroke : 86.7
3.7l
Bore: 95.5
Stroke: 86.7
4l
Bore: 96.5
Stroke :91.44
3.5 with super six crank
3.7l
Bore 92.5
Stroke: 91.44
3.7 with super six crank
3.9l
Bore:95.5
Stroke:91.44
Morale of the story the 3.7 is a better starting point for really any serious application, the fact that you won’t have to machine the block to accept the pistons to stroke to the close to the 4l displacement the engine is money saved to put elsewhere in the build. And you could probably run the 3.7 l with the stock internals plus ring gap up as high as the ecoboosts upper limits.
