Is anyone knowledgeable about the 3.5 liter upgrade? I'm having issues with an oil leak. Just want to know, will an MDX short block swap right over to the 3.2 TL/CL-S heaads, sensors, etc? Or do I need to just get another 3.2 block for compatibilites sake?

 

You'll need custom pistons. The longer stroke of the J35 plus the Type-S head will increase compression ratio too much. I wonder if you could just double up on your head gaskets and lower the compression ratio though.

I have been told that the J32 block cools better than the J35 though. And the J35 crank and rods will fit in the J32 block, but again you'll need new custom pistons to keep your compression ratio in check, especially considering how much boost you are running. Last time I checked pistons were around $800 for the set and Speed Distributors may still have a set on the shelves. I know they did back in Dec of '04.

 

well im not sure it'd be that much a problem, the jun,toda and spoon stroker kits all bump compression to 12:1

 

I thought there was a couple of people that had the 3.5 liter block with the cl-s heads on the forums.

 

maybe 1 or 2

 

Yes, but he's running 9psi of boost.

 

Yes there are but the pistons used are not an off the shelf Acura/Honda part.

 

not true...theyre just not the pistons that came with the car...so why wouldnt he just use the ,mdx/oddessey rods and pistons to achieve the 10:1 compression those cars have

 

the 01-02 mdx block, (basic block) is the same as the j32. as steve said, the crank and rods make up the extra displacement. the pistons are different in that the compression ratio is 10.0:1 on the 3.5 and you know what it is for the cls. the heads will bolt right onto the mdx block. I Beleive the cls cams have slightly more lift than the mdx which may create a piston to valve clearance issue, but the only way to tell is to clay it up or use other creative methods to check the clearance.
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so if you went with a basic 3.5l shortblock, it would have slightly less compression ratio, which may be enough to miss the valve on TDC. All the sensors, holes for brackets, and heads will bolt right up. I would say that if you used the mdx shortblock you would have no problem with the valve to piston clearance, but to be sure, it should be checked. I'm not sure just how much typeR's conversion was massaged in that respect.
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if you check the oem part numbers for a basic block (not shortblock), you will find the j32 and j35 are the same part number, except for certain model years.

 

ThinJim - I understood the Type-S heads to have smaller chambers than the MDX heads (I think Velocity cc'ed both). The calc I heard was 10.85:1 when putting the Type-S heads on the standard MDX block. OK for allmotor and 92 octane but bad for boost.

 

It may have, but i've never been able to see the mdx head.

 

10.85:1 is what my car has not sure every 3.5 is gonna have this same ratio

 

10.85:1 is still fine for boost. The RSX guys push 11.0:1 and run 9psi. The S2K guys have 11.5:1 and run 6-8psi.

 

Yep, it's common misconseption that you can't run the boost on high CR. You can with good tuning and less amount of boost than low CR.

 

With 3.5L block, visual inspection of the pistons is necessary to make sure the Type S valves (intake) will have enough clearance. And J32A2 heads will fit right in on J35A* block.

 

Search

 

No pun intended as I too say use the search and I do use it. But for this particaular conversion there is hardly enough info, from my searches I ran a few days ago. I may have typed wrong keywords so if you could post link very much appreciated.

 

I seem to remember someone in FL. posted a complete parts list and some instructions about the 3.5L conversion. There were also several rather extensive posts with lots of good info.