3300->3800 interchangeability...

[xscotty308]

does anyone know if the heads from a 3800 will directly bolt onto a 3300 block? i scored an ENTIRE series1 3800 SC upperend, head, intake, SC, injectors, you name it! price...FREE so, my plan is to boost her GA with the aforementioned parts. i may be ableto get the tranny too, but i gotta ask the boss on that.

so..any clues?

[Shad0wguy]

FREE...how?!?!

[xscotty308]

i work at a local garage. one of the "resident" jobs, is a motor swap on a 95 Park Ave Ultra... we have another donor car from the customer, so we have a blown motor and good tranny in the owned car, and the donor... swap away and the customer is happy! from what i can make out, the lower end is junk, but the top end... well ya know... :)

[DSMMAN]

Sounds like you made a nice little lick .

[urweak]

I would try to compare the two heads as much as i could side by side (maybe go find a 3300 head out of a junk yard) Do some calculations to see what C/R you might get with the 3800 head on the 3300 block. then see if you can bolt everything up ontop

Or just see if you can get the intake mani and S/C to bolt up.

You also might want to get some info on the pinouts of the ecu in your car, and the one in the donor, if they match up i would try to run the donor car ecu so it can read boost.

But whatever it comes down to, you will have to do alot of home work, since your pretty much charting on uncharted water.

[PontiacGA]

I believe the series I 3800 is very close if not identical to the 3300. I was wondering if the series I S/C and upper intake would fit on the 3300, or at least the 72mm TB would. :D

[xscotty308]

DSMMAN - no licking, its was either throw away perfectly good parts or use them... what would you do?

urweak - i know im going in uncharted water here, but hey someone has to do it. winter is here, and i need a project or 2. i was planning on visually inspecting the 2 diff. heads and seeing "what differences" there are. i have a feeling there wont be many that'll make it difficult. the biggest thing im afraid of is comp.ratio, i'm sure the SC motor has a lower comp. ratio then the 3300 so i gots to somehow tackle that. the other thing that'll suck is the tranny... wish someone here posted ALL the info after the swap was done so that others like myself can do the swap in a weekend...

PontiacGA - im gonna try just bolting on the intake/SC setup on the motor while on a stand, then see if the stock front motor mount plate thing still bolts on, i know im gonna be moving accesories around, A/C will be leaving shortly...LOL

[pokesmot]

Was wondering if you had a chance to compare cylinder heads yet?

I have the heads off of my old 3.3 sitting in the garage as spares for now. If you need some pictures for comparing bolt up patterns I can help you out there, as I would also be very interested in putting 3800 heads / intake manifold / supercharger on a 3300 block if possible.


I love the 3300 series engine, only problem I have with it is that there aren't enough performance mods availible for it :( (that and the oil filter is in a very STUPID location.)

[DSMMAN]

DSMMAN - no licking, its was either throw away perfectly good parts or use them... what would you do?


It was a figure of speach meaning a lick like you came off .... I would have done the same shit you did. Any progress on the situation ? Im curious to see your findings.

Keep us posted

[RocketFast321]

Originally posted by PontiacGA
I believe the series I 3800 is very close if not identical to the 3300. I was wondering if the series I S/C and upper intake would fit on the 3300, or at least the 72mm TB would. :D

Just like the 3100/3400/3500

[GrandAmMN]

An interesting point: When I replaced the intake manifold gasket for my 3300, I got the replacement at NAPA. The package was labeled as '3300 / 3800'. What was strange was that. although the gaskets were the same, the end seals were not correct. When I took them back, they had an alternate '3300 / 3800' intake manifold gasket set with slightly different seals that fit. It makes me wonder if there is a slight difference between the two? Who knows...

[93grandamv6]

i would really like to know if the supercharger from a series 1, or 2 grand prix gtp, would fit on the 3.3l. if so, what mods would have to be done?....please if anyone knows, give me an answer, i was thinking of doin this to mine, but i dont know what i might need to do in order to get it done.. also, do you think a 3.8 would fit into a 93 grand am?

[ViperDVMan]

I heard that the 3300, though being close to if not identical to the 3800, had a slightly smaller bore as well as the shorter stroke than the 3800. So that would make using 3800 heads rather impossible since their bores don't match (unless you bored out the block).

But I too wonder if its intake and exhaust ports and bolt patterns are identical. If the bolt patterns on those manifolds are identical, then you shouldn't need to use the 3800 heads....just the accessories that bolt onto them. However, it does make me wonder just how much off a pre-Series I or Series I 3800 you can use on a 3300.

As for dropping a 3800 into a Grand Am.....the bell housing patterns should be identical since they are on the same base engine. The only thing that might prevent it from fitting in a Grand Am is the front motor mount locations compared to the 3300, since no N-body used the 3800. If the front mounts are the same, then you just need a different wiring harness and ECM for the 3800.

[xscotty308]

the 3.3L and the 3.8L are the essentially the smae motor with the exception of bore and stroke. bore size has little to do with which heads will work. on some engines it does matter due to valve arrangement, however im sure that wont matter. much like the 305/350 heads. the only difference between them is the combustion chamber size in the head. im sure the 3.8L heads will have a bigger comb. chamber thus dropping static compression ratio and hopefully making a boost friendly motor. i just finished the motor swaps and now am waiting for the OK from the customer to take all i want from the junk motor. from what i can see everything from the block forward is SC'd specific. im 99% sure all of the bolt holes will line up and bolt on. the problems i now see are mainly 5 things.
1.) the P/S pump gets moved down towards the halfshafts which means custom P/S lines.
2.) heater core lines will have to be even more custom as the in/outs are over by alternator, not over by the TB side like the 3.3L
3.) fuel lines, gotta go custom there too..
4.) creating a spacer bracket that'll connect that aluminum bracket to the 3.8 SC front(water pump side) motor mount. though this looks easy...
5.) to find another 3.3L GA and do this work, melissa left me of 6yrs and no longer have her GA to tinker with....

Originally posted by ViperDVMan
I heard that the 3300, though being close to if not identical to the 3800, had a slightly smaller bore as well as the shorter stroke than the 3800. So that would make using 3800 heads rather impossible since their bores don't match (unless you bored out the block).

But I too wonder if its intake and exhaust ports and bolt patterns are identical. If the bolt patterns on those manifolds are identical, then you shouldn't need to use the 3800 heads....just the accessories that bolt onto them. However, it does make me wonder just how much off a pre-Series I or Series I 3800 you can use on a 3300.

As for dropping a 3800 into a Grand Am.....the bell housing patterns should be identical since they are on the same base engine. The only thing that might prevent it from fitting in a Grand Am is the front motor mount locations compared to the 3300, since no N-body used the 3800. If the front mounts are the same, then you just need a different wiring harness and ECM for the 3800.