Trying to get some performance out of my 2.5

[RAD Merc SVT]

Hey guys I'm rebuilding a 2.5 svt and want to know what kind of air/fuel stuff I can put on. My main concerns are TB and Injectors. If I run an NPG CAI, MSDS Headers and y-pipe, along with the SVT heads, cams, and IM would I benefit from an optimized 65mm TB and bigger injectors? with an Xcal3 tune of course. Any help would be greatly appreciated. Thanks, Brian

 

[RAD Merc SVT]

Well I'm assuming nobody replied because I should be able to figure it out on my own. So I did a little searching and from what I read from your posts is that I think I'll be ok with 24# injectors and an optomized 65mm Throttle body. I'm also gonna look into porting my heads and IM's. I guess i'll read before I post next time.

 

[prozak1986]

our cars came with 17# injectors , 24# injectors is way over kill with the mods your talking about , try 19# injectors ( you will need to get a tune thow )

 

[imnotacop420]

Well I'm assuming nobody replied because I should be able to figure it out on my own. So I did a little searching and from what I read from your posts is that I think I'll be ok with 24# injectors and an optomized 65mm Throttle body. I'm also gonna look into porting my heads and IM's. I guess i'll read before I post next time.

If you are staying 2.5 and dont plan on any F/I I would say your stock injectors should be fine. if you are going to throw the 65mm TB on there I would only do it if you are planning and porting/polishing the heads and intakes. Check out Sho-Source, they might still have a couple big bore LIM's left over from our group buy. 65mm TB would probably be overkill with just intake and headers. I have one on my 2.5 with a max extrude honed UIM......I still prefer the optimized SVT TB over the 65mm.

our cars came with 17# injectors , 24# injectors is way over kill with the mods your talking about , try 19# injectors ( you will need to get a tune thow )

He has an SVT, should already have 19# injectors.....

 

[RAD Merc SVT]

Alright thank you guys for the help. It turns out the salvage yard that said they had an SVT engine doesn't know what they're talking about so I'm just gonna rebuild the one from my LS Mystique. I just e-mailed SHO-source about the Big Bored LIM. If I got that done and port my heads and UIM with the intake and headers then what would I do? I believe the non SVT duratec has a 55mm TB so would I optimize that or go larger? and put in 19# injectors? Also any recommendations on how far to port the heads and intake out? and did 19# injectors come from any other cars? Thanks alot guys

 

[mrspindlelegs]

If you are going to have the motor rebuilt, you may want to consider replacing the factory connecting rods with the K-1 forged rods (or other aftermarket forged rods). The SVT motors are well known for spinning bearings. Some people will say the root cause is the oiling system in this motor but it really is the powdered metal scintering process used to make the factory rods. The rod ends stretch over time which eliminates the crush force that holds the bearings in place. This upgrade is not a horse power builder itself; it is a longevity increaser. Of course, rebalance the motor if you do this and put in Clevite bearings while you are at it.

 

[RAD Merc SVT]

haha well ironically the whole reason I'm rebuilding the engine is because of the notorious rod knock. I drove with it ignoring it for a while and then it got really bad. So I gotta inspect the bottom end and probably replace the crank. I was already planning the clevite bearings but 750 dollar rods?... I know I need them but ...sigh...

 

[striker2]

take your rods to a machine shop and have them check the rods first. even if they are slightly out of round they should be able to machine them and then order you bearings for them.

 

[bgrogan01]

Ok well I'm gonna say this because no one else has but why not go 3L? Isn't rebuilding a 2.5 a waste of time?

 

[RAD Merc SVT]

Well actually I've been considering the 3L recently and I've spent alot of time researching it but I feel like with something like that it's gonna just be one problem after another and I really just need to get my car running. But I do love power. Does the 3L have the same rod knock issue? I would use clevite bearings.

 

[BrApple]

a 3L isn't a problem if its build correctly and no corners are cut. it seems most 3L builds that have issues are because they are being built as cheaply as possible and with not enough knowledge.

 

[RAD Merc SVT]

Well I've done alot of research and I almost feel like I can do a 3L with my eyes closed because I've read almost every thread on them. I have also rebuilt engines and I'm good at problem solving. My problem is I need my car running, if this turns into a huge project my dad is gonna be pissed, and my local salvage yard is selling an 04 taurus engine for... 700 bucks! I hear you guys get them for like 300. Sometimes I hate my hobby.

 

[mrspindlelegs]

take your rods to a machine shop and have them check the rods first. even if they are slightly out of round they should be able to machine them and then order you bearings for them.

My recollection is that you cannot do this with connecting rods that have been manufactured by the powdered metal scintering process. The rods are "fractured" to create the bearing cap end that goes on the crank. The normal process of fixing "out of roundness" is to shave-off some material on the bearing cap & con rod mating surfaces first to shorten the elongated dimension before machining the overall bore back to roundness. If you do this with "fractured-face" rods, you lose the unique mating surface that keeps the cap properly oriented to the rest of the connecting rod. If I am wrong and this can be done, who makes the bearing with the larger outer diameter (or sleeve) to maintain bearing crush?

 

[striker2]

im pretty sure it can still be done, but im not sure who makes larger bearings for that purpose. would have to ask a machine shop to be positive.

even if they cant its still worth taking them to have them checked.