Hey, so i got an HO manifold from a guy here in BC, with the tb and phenolic adapter and such, and i wa just lookin at the part the other day contemplating the date of the install, and i noticed that when i line the adapter up to the mani, the ports on the adapter are qutie a bit larger than the ports on the flange. Just wondering if thats normal, it got me thinking lol
to match them, get some bolts and nuts and tighten the adapter to the mani, putting two 2.3 intake gaskets between them. one will be used between the head and adapter and the other between adapter and manifold. get a dremel and grind the ho mani to match the 2.4 flange. also you'll have to figure how you will run the pcv. if the adapter flange you have covers the pcv hole drill and tap the mani, but if not you'll have to drill and tap the head and put a fitting. its really a pain in the ass. you'll need longer bolts and if you have an egr thats gotta go. best bet is not to mess with it and use the stock intake mani and bore the throttle body.
ive heard the stock intake mani is garbage tho :s any other options? that sounds like a major PITA like u said
what is your plan with your motor? i would put some cams in and a header with a full exhaust before changing intake mani. when i did my minor build i did everything i have at once.
but there is a venom intake mani that is the stock shape but is metal. i'd rather have the HO or LO before that one, but thats me.
i would post step by step pic's for you for the ho mani but my computer with the pic's has crashed.
ya its all in the works, but i got this HO for practically free so i figured why not
just take a dremel and grind out the manifold a little to match the ports. its pretty easy and can be done in less than an hour including slotting the bolt holes
Eat my shift
Couple of things....
you are going to need to create PCV vacuum channels in the adapter... so you do not starve your system.. see picture below
Also.... make sure the porting is matched. The flanges were not CNC correctly on some of the older flanges, where the porting on the manifold vs the block bolts do not line everything up correctly. See the picture below of the step you DO NOT want to have... you may have to slot the flange bolt holes to help align the manifold correctly. And like said above.. you will need to slot the Manifold holes to allow better fitment..
Anyway.. hope this helps and answers your question.. and good luck.
oh.. and I forgot to add....
Get a FELPRO gasket blank.. and create your own gasket for both inbetween the adapter flange/manifold and the block.
This way you can prevent vacuum leaks in your PCV system.
Also when you get to the air/oil separator vacuum line part.. make sure the one goes to the crank case... and PRE-Throttle body... not to the manifold.... some people make this mistake and over pressurize the crank case... creating oil leaks in the heads.... or they put a mini-filter on... which does not allow any sort of vacuum flow with-in the separator
glad someone could help you. i totally forgot about how he did it if the adapter covered the pcv hole. many ways to do the pcv setup.
zdoubledozen [ Matt wrote:]
damn just noticed in the pic how bad of a jump from the adapter to the head. mine is NOT like that. my adapter matches the 2.4 head perfect. i dremeled the adapter to match the manifold with a SMOOTH transaction. NO jump like that what so ever.
maxZ24 wrote:zdoubledozen [ Matt wrote:]
damn just noticed in the pic how bad of a jump from the adapter to the head. mine is NOT like that. my adapter matches the 2.4 head perfect. i dremeled the adapter to match the manifold with a SMOOTH transaction. NO jump like that what so ever.
Yeah its too bad this part was over looked when these adapters were made.
it's a damn shame ! lol
Sadly... people no not notice this step, because some will install the adaptor onto the manifold prior to installation onto the block. (I'm will raise my hand and say I missed this.. the first time I attempted the install) lol
i would of not done the swap if it had a jump like that. i got my adapter from vulcan turbo. i think they are using the adapter i got for the eco supercharger on the ld9 to reduce heat soak. you see what i used it for. one day i'll be turbo'd. i remember the post when the guy dyno'd it and lost 10hp from the swap. i bet it had that HUGE jump like that.
maxZ24 wrote:i would of not done the swap if it had a jump like that. i got my adapter from vulcan turbo. i think they are using the adapter i got for the eco supercharger on the ld9 to reduce heat soak. you see what i used it for. one day i'll be turbo'd. i remember the post when the guy dyno'd it and lost 10hp from the swap. i bet it had that HUGE jump like that.
It might be possible...
rest assured..... I slotted my flange holes so the ports match.
K so i just noticed maxz24 basically ground away the adapter where the pvc is... does that work? or do i gotta do that stupid slotting stuff, i never got around to doing this, and im gunna do it this weekend, i got no work and no plans
^^^ it works great how i did it.
the steps:
take head off
drill and tap pcv hole for a 1/8 npt fitting
screw in fitting
put head back on
dont forget all the other bull@!#$
why is it that some of these swaps use that phoelonic spacer and some dont?
^^^ because people are different
lol but is a spacer needed?
many questions... here are some answers
the 10 hp loss came from a guy who took a 2.4 flange and welded it to the HO manifold. no spacer was used whatsoever. The spacer acts as a heat barrier and resists most of the heat going to the manifold allowing it to stay cooler, such as a the stock plastic manifold. --- the guy that lost 10 hp ran with his HO mani hot to begin with and the 2.4 mani cold. So the test needs to be done again with a spacer and both manifolds cold.
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my spacer has a jump like that... i personally talked to Chris Fontana about it a few months ago and he said that most people either ported their head to match the spacer, or just lived with jump... he didnt mention anything about notching the holes to slide it up... i dont have the adaptor and my head in front of me but i dont think you could slide it up because then it would jump at the top. im kinda afraid to port the head out to match the adaptor because that may be to much if i ever want to go back to stock. (please please correct me if i am wrong)
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as for the venom mani, its too expensive to see no gains over the HO mani...
so what years are these manis from, i pulled one of a 93 grand am #24370433, just wondering if this is the one im looking for, weird part was all the badging on the car was v6 lol, and what parts associated with the intake do i need for the swap?
