3.1 to a 3.4 topend swap

[pontiacmaniac94]

okay, so what all would i be able to take from a 3.4 that would bolt directly to my 3.1? also, what car could i pull it off of? is there anything i should be worried about when doin it? any common problems? also, what would i gain from this? anything noticable?

 

if you all dont already know, i have a 94 grand prix with the 3.1, and wanting to know what all i can do that is cheap and easy.

[Crazy K]

1st step... clarify.

 

are you taking about a 3400 topend swap onto a 3100?

 

not a dohc swap, correct?

 

 

 

I have done this on a 95 3100, and am contemplating doing it to a 94...

 

[Venom]

I believe everything from the heads up can be swapped. The biggest gain is the 3400 intake and heads flow better. Plus while you have them off you can port them for even better flow.

[3.1cutlass]

You will also need things such as custom length pushrods. IIRC the A/c and alternator brackets are different.

[Crazy K]

for a 3100 sfi to 3400 swap, pushrods are the same.

 

for a 3.1 mpfi to 3400 topend swap, custom pushrods and tuning is needed.

[White93z34]

the change to roller rockers will be a pain since you have a 94', they didn't start provisioning the heads for the roller rockers till mid 95'

 

you could either swap 95.5'+ heads on, also you *may* be able to make the necessary modifications to your current heads to allow they roller rockers to fit.

 

also, I think I have heard of people grinding away part of the LIM to make their old style stamped rockers clear.

[pontiacmaniac94]

1st step... clarify.

 

are you taking about a 3400 topend swap onto a 3100?

 

not a dohc swap, correct?

 

 

 

 

 

I have done this on a 95 3100, and am contemplating doing it to a 94...

 

 

correct. i dont want the wizbang 3.4 dohc, just the 3400....

 

 

top end, i was mainly just thinkin about doing the plebum, and the throttlebody....not much more, i dont want to change to rockers, that is more work than its worth.

 

 

so i guess i am asking if this we be any better? also, my car does not have a MAF sensor, so what motor could cannibalize off of with a 3400 that is the same as me?

[Crazy K]

If you can successfully clearance the rockers (what i would do too) ANY large port 3100 or 3400 upper and lower intake will work... as long as they have the throttle body on the D/S.

 

next question. OBDII swap as well? or you will have to buy or make an EGR adapter.

[GP1138]

I had a '95 and my heads were notched for roller rockers, so all I had to do was swap the rocker arms from newer heads. I do not think you can notch the pedestals on the heads, but some choose to grind the lower intake for clearance for the roller rockers.

 

It's debatable whether it's useful, I gained some top end grunt, and lost some low end, at least the ass dyno told me I did. It definitely pulled longer up high though.

[19Cutlass94]

wow... way to make it complicated guys

 

 

Get a 3400 top end. Thats heads, intakes, TB, MAP bracket, and alternator brace. Thats really all you need. You just need to make sure of the coolant tube going into the LIM. The 3400 will more than likely be pressed in, so youll need that tube as well as yours is threaded.

 

A motor is a motor, it doesnt care what OBD system it has or what sensors run it, since the 3100 and 3400 are the same motor, but just different bores and port sizes. If all your wanting to do is a plenum swap, then just grab the plenum, MAP bracket, and TB. thats is. That shouldnt take you more than an hour to change.

 

 

Its very simple, to do and theres really not much to it.

 

[GP1138]

Its very simple, to do and theres really not much to it.

 

Agreed. Aside from the '94-'95 differences, it's pretty plug-n-play as far as difficulty. You have to swap throttle linkage as well, from the 3100 to the 3400 throttle body.

 

Some people don't like to mess with the heads. I know I hate removing heads, it's a pain in the ass to remove exhaust pieces, and in my case, I didn't even need to remove the heads, but I thought I did, and it created a headache.

[pontiacmaniac94]

wow... way to make it complicated guys

 

 

A motor is a motor, it doesnt care what OBD system it has or what sensors run it, since the 3100 and 3400 are the same motor, but just different bores and port sizes. If all your wanting to do is a plenum swap, then just grab the plenum, MAP bracket, and TB. thats is. That shouldnt take you more than an hour to change.

 

 

Its very simple, to do and theres really not much to it.

 

 

okay, i like what i see here, so would i get anything out of this? and also, one of the other guys on another forum was telling me to get a TB outta of 3400 montana because it was 56mm instead of the plain jane 52mm...... and the MAP Bracket, do i need the MAP too? or is that just a stupid question?

 

 

[19Cutlass94]

Your 3100 TB is a 52 ALL 3400's got a 56mm TB. You friend needs to learn more. Youll need the map sensor bracket, but not the sensor. You can use ALL YOUR 3100 SENSORS.

[pontiacmaniac94]

Your 3100 TB is a 52 ALL 3400's got a 56mm TB. You friend needs to learn more. Youll need the map sensor bracket, but not the sensor. You can use ALL YOUR 3100 SENSORS.

 

what about the EGR valve? will that still work? or do i need an adapter?

[19Cutlass94]

Your 3100 TB is a 52 ALL 3400's got a 56mm TB. You friend needs to learn more. Youll need the map sensor bracket, but not the sensor. You can use ALL YOUR 3100 SENSORS.

 

what about the EGR valve? will that still work? or do i need an adapter?

 

depends on what yr plenum you get and from what car, but yeah you will more than likely need one. 60*v6 sells them, and they give you a list of the 3 gaskets you need.

[89SupremeCutty]

is there a noticable gain with just the upper and lower intake and the tb? do the heads have to swapped to put both lower and upper intake on?

[Crazy K]

is there a noticable gain with just the upper and lower intake and the tb? do the heads have to swapped to put both lower and upper intake on?

Having done this swap ans done it right, so my EGR worked and having no exhaust leak... i think it is an improvement.

 

do you have to swap the heads? no. you would get better performance if you did, but it;s alot of work and $$$ if your engine is running fine anyhow. I did the 3400 upper intakes and was able to convert to roller rockers in my 95, sticking with the 95 heads... granted, the motor was a low mileage crate motor.

[89SupremeCutty]

sorry about hijacking the thread i've been thinking of doing this swap for sometime and since someone else brought it up, why not ask questions instead of starting a new topic.

 

anyways....

 

if i were to do just the intake swap would i need both upper and lower intakes or could i just use the upper? to me it dosn't seem like it would take much just to swap the heads.

[Crazy K]

sorry about hijacking the thread i've been thinking of doing this swap for sometime and since someone else brought it up, why not ask questions instead of starting a new topic.

 

anyways....

 

if i were to do just the intake swap would i need both upper and lower intakes or could i just use the upper? to me it dosn't seem like it would take much just to swap the heads.

you need the upper and lower, as trying to mix and match you would see that they don't line up.

 

the major difference in the heads... is that the exhaust ports have been ported. again, doing heads costs $$$$, so if your heads are ok, I'd leave em be, unless you really think $$$$$$$ is worth spending to get merely a few horses if that. I believe some people have ported the exhaust ports on the older heads instead...

 

actual differences on heads:

94-95 have a tapped hole for the temp sensor of rear corner, 96+ don't

94 has no roller rocker provisions, 95 has provisions but no roller rockers, 96+ has roller rockers

center intake guide pin was changed when the move to a larger intake was performed.

ported exhaust ports mentioned above when the move to a larger intake was performed.

 

 

[89SupremeCutty]

thanks for the info. i was thinking that you HAD to do both lower and upper but wasn't sure. so if i got an intake from a 96+ vehicle it should interchange no problem? i have a 98 which is why i ask.

[pontiacmaniac94]

hhmmm....so i am thinkin about starting, so if i take the part directly underneath the plebum, i need to grind down the rods? and also, i need the lines too?