questions on heads/ xe258 cam upgrades...

[merc91]

alright i've got a nice low km's lopo motor that I would like to keep in thier if possible, but I want to swap on GT40P heads and hopefully a xe258 cam.
I will be converting to mass air, all the supporting mods... basically everything up from the long block, and getting a professional tune to bring it all together.

It is my daily driver which is why I don't want to be getting into getting another motor to build up and have to make fit and the pop-up problems that always show up... and money is somewhat of an object, I can and will buy everything the swap will need, and of good quality...I just can't afford to be buying different cam's and heads and rockers and all that, through trial and error with clearences, not to mention i'm hoping to make this a 1-2week job tops so if i can get a surefire list of parts together for the swap to go as smooth as possible i would be a happy guy.


All that being said, so ya's know my plan, lets get into the tech and after lots of reading these are my questions at the moment and any other points you guys can add on the subject would be appreciated allot...

-with stock lopo pistons and GT40P heads, will the comp xe258 cam work without piston/valve contact? ...it's high lift but short duration so i'm not sure...and i will be using 1.6 rockers of course.

-will I still be able to pass sniffer emissions testing (assuming engine is in ideal running order) with the different EGR setup on the GT40P heads, and using the xe258 cam?

-.510" springs won't do the job with that cam will they?

Thanks guys, If I can snag this summer job I'm going to be needing lots of help with motor/tranny info as I can not think of a better way to finally make and spend some cash, than on the old girls motor.

[jayh]

shouldnt this be in "engine performance"?

why P heads? you are better off with plain old gt40's for many reasons

as far as PTV issues, you should always measure, but duration and overlap are bigger killers than lift, PTV occurs near TDC, not at peak lift

you can do a head swap in one weekend

theres absolutely nothing wrong with building up a lopo

[merc91]

yeh I realized it would be a good thread for performance right after I posted it of course...used to the old one that was over 300hp (double mine) haha. If someone could scoot it over to performance that would be good.

-well I don't mind getting some "P" headers, and from what I've seen "P" heads are worth the extra bit of work for the extra power they can offer.

-definently I will measure with some clay for clearance, but just wondering if anyone has tried this cam or a similar one and had success with LOPO pistons, or if it doesn't provide clearance in which case I won't spend the $250 on the cam.

[91grandmarquis]

If your interested I have a set on non P gt40s with only about 6k on them since a rebuild. (thats what I was told when I bought them) I can't confirm it but if your interested let me know. They look almost new.

Also It would be a safe bet to just check the PTV unless someone around here was running that same combo.... I'm not sure that there is.

[jayh]

imho you would be better off running the stock HO cam on the cheap, get 1.7's instead of 1.6's, get some standard headers used, then with the money you just saved from cam and headers, get a better cylinder head

[zoomie]

alright i've got a nice low km's lopo motor that I would like to keep in thier if possible, but I want to swap on GT40P heads and hopefully a xe258 cam.
I will be converting to mass air, all the supporting mods... basically everything up from the long block, and getting a professional tune to bring it all together.

It is my daily driver which is why I don't want to be getting into getting another motor to build up and have to make fit and the pop-up problems that always show up... and money is somewhat of an object, I can and will buy everything the swap will need, and of good quality...I just can't afford to be buying different cam's and heads and rockers and all that, through trial and error with clearences, not to mention i'm hoping to make this a 1-2week job tops so if i can get a surefire list of parts together for the swap to go as smooth as possible i would be a happy guy.


All that being said, so ya's know my plan, lets get into the tech and after lots of reading these are my questions at the moment and any other points you guys can add on the subject would be appreciated allot...

-with stock lopo pistons and GT40P heads, will the comp xe258 cam work without piston/valve contact? ...it's high lift but short duration so i'm not sure...and i will be using 1.6 rockers of course.

-will I still be able to pass sniffer emissions testing (assuming engine is in ideal running order) with the different EGR setup on the GT40P heads, and using the xe258 cam?

-.510" springs won't do the job with that cam will they?

Thanks guys, If I can snag this summer job I'm going to be needing lots of help with motor/tranny info as I can not think of a better way to finally make and spend some cash, than on the old girls motor.

The XE258 will require new springs cam has .533 and .544 lift here is the springs i woudl reccomend(actually th eones im getting when i get this cam)#26986-16 they are beehives. and matched for this cam i would also reccomend 1.6RR and possiably new lifters as well here is a link for cam and spec stuff it needs.
notsure how gt40p heads will work with that combo ,but as an educated guess you should be able to pass emissions with it. you may have to have the pistons notched, but as i said before not to sure about it i have to do some more reading. good luck mang and hope the info was helpful.

[merc91]

The XE258 will require new springs cam has .533 and .544 lift here is the springs i woudl reccomend(actually th eones im getting when i get this cam)#26986-16 they are beehives. and matched for this cam i would also reccomend 1.6RR and possiably new lifters as well here is a link for cam and spec stuff it needs.

this all makes allot of sense with such fast ramp rates an high lift, to have a smooth, high capacity valvetrain to keep it all from getting slopy.

as of right now i think i'm sticking with the "P" heads since they are designed for daily drivers to pass emissions, and thier about the best ford head power wise that will still not cause me to many headaches...plus it is a daily driver for now and i know better heads would be beneficial to me if i took it to the track or had no e-test every 2 years but as of right now i'm liking the idea of "P". In a few years I will be doing up a nice 351 top to bottom brand new aftermarket heads and the works...so for now making 275-300hp at the flywheel or so would be awsome until then.

I guess what I would really like to see is someone sucessfully running a similar cam or this one. If its not gunna fit then the xe258 cam, springs, 1.6RR's and other stuff would be a fair bit of dumped cash if i have to throw in a HO or explorer cam and new 1.7's.

thanks for the info...it all helps allot and keep er comming!

[jayh]

alot of heads will pass emissions with the stock HO cam. changing the cam would start to gamble on clean exhaust for passing e-test, that cam is probably mild enough, but the HO is guaranteed to pass. changing the cam is more of a gamble then changing the heads as far as e-testing goes

[gadget73]

EGR will work fine on P heads. They don't have air injection ports, but thats useless anyway. The EGR passage is in the center of the intake runners, and it will work as expected. You will get codes for an inop air injection system, but it will not set the check engine light and nobody will know unless they code scan your car. If visual is a problem, you shoul;d be able to bolt the stock air injection manifold up and just have it there to look pretty.

If you already have the P heads, keep them. They need special headers but if you were doing headers anyway its not that much more expensive to get P headers. You will need exhaust to let the motor breathe. The stock crap is not really gonna cut the mustard. If you're flat broke you can do it but its not going to do you any favors and you'll have problems fitting the headers up. 90TC manifolds will help things mate up, but they aren't exactly high performance parts.

You can run either a 1.6 or 1.7 rocker. You'd get more lift total with a 1.7, but if you have 1.6's already, run them.

I'd definitely clay the motor just to be double sure nothing hits, but you're probably safe. Never assume though, fuckups with PTV clearance are not pretty and not cheap. I have a set of P heads that I had to replace all the exhaust valves in because some idiot didn't check that.

Stock mass air will probably behave OK with this. Tuning will get you more, but I'd wager it will be very drivable if you have the right (stock) MAF. No need for fancy aftermarket meters, one from a 94-95 Mustang will work fine. I actually have one from a 4.6 panther that has the same electronics as the coveted sn95 MAF and it works fine.

What do you have in mind for an intake? At a bare minimum, I'd say Explorer, but a ported Explorer lower or something aftermarket will be a much happier match. Ported stock lower will also do the job, those breathe a smidge better than a stock Explorer lower if properly ported but you're gonna spend at least as much to have the stocker ported vs finding an Explorer intake. If appearance is an issue for emissions, the stock Ford castings are probably the way to go.

[zoomie]

there is a crane equivalnt to the XE258 it is the crane 2020 cam, forgot to add that in as well. from what i gather the XE258 should be ok with no p/v issues it has almost the same specs as the stock HO except for lift,which has alot so 1.6 RR will the ones for that ill do some more research on the crane 2020 an dpost info when i get it.

[jayh]

the thing is you can find regular headers cheap used

lol my rep meter took a beating for saying "you will need exhaust to let the motor breathe"

I agree with everything said, but look at my perspective also

[zoomie]

headers are a good thing no matter what head they are on mustang guys are probably the easyest way to find cheap parts i got my BBK headers and most of the exhuast for 100 bucks. but the p headers arnt so easy to find though.

[merc91]

I actually did all the exhaust already with stock but stainless shorties, BBK 2.5" H -pipe, highflow cats, and 2.5" pipes with flowmasters dumped at the axle...I will be getting some nice new headers so might as well go with the "P" since i'm getting new performance headers anyways. And I have done a trac-lock 3.73 rear end, and will be getting a good transmission kit put in prior to the motor buildup. I wanted to get the supporting parts looked after before I went rushing into motor mods until I was ready to do it right.

Actually lucky for me visual inspection is no problem, the only thing i need to do is pass a sniffer test and i'm good to go. But anyways the emissions info you gave for his setup is much appreciated.

I have explorer upper, lower, and TB in mind with a matched 65mm EGR plate which I can machine out at school like my one for the HO stuff on their now... For the EGR spacer, I can do damn near anything in the shop so other than a lightening unit, what is it that can be bored out and just add in the studs for the throttle cable bracket. Is it the plain HO EGR spacer?
I will take your advice and get some prices on some mild porting jobs for the explorer setup also.

Gadget and zoomie, I appreciate your help allot and I'd love to hear anything else ya's have to add.
Jayh...If passing a sniffer test wasn't such a pain for me I would be going with aftermarket heads and cam, and intake... like your recomending but I feel better about going with just an aftermarket cam so worst case I have to throw in a HO cam to pass an e-test vs throwing out a mint pair of aftermarket heads which would kill me.

[merc91]

-and if converting to mass air, should I go with a HO engine computer (i don't care about losing cruise)
-should I still stick with 19Lb injectors to swap in
-what would ya's do in terms of pushrods...just basically get the heads on and cam and the put in a stock pushrod and measure the difference and order new rods? It's probly better than playing the guessing game to pick the right length ahead of time.
-Should I get the spark plug for the explorer GT40P and gap it to explorer spec?
-and should i run this fuel pump until i see problems with it keeping up or swap it out with a larger capacity?

[gadget73]

P headers are not as easy to find used, nor are they as cheap. Very true.
On the other hand, non-P heads are harder to find, and not as cheap.
Combine those two facts, and its almost a wash.


You need the Lightning EGR spacer on an Explorer upper, or you'll need to use a Mustang part and make a bracket to bolt up your throttle cables to it. The stock spacer doesn't have enough material to machine out to match a 65mm throttle body.

If you're going mass air, you have to use the HO ECM. There is no way to use a MAF without a mass air ECM, and the only one thats really compatible without a bunch of BS is the A9* Mustang brains. Expect to pay about 75 bucks for one.

19# injector should be fine, but if it turns out to be lean, a 24# and a tune will fix it nicely.

Modify a stock pushrod to be adjustable, or buy an adjustable to determine what length you need. No point trying to guess at it.