Originally Posted by Honda News

VTEC(R) (VARIABLE VALVE TIMING & LIFT ELECTRONIC CONTROL)

Acura's VTEC(R) (Variable Valve Timing and Lift Electronic Control) gives the TL and TL Type-S engines strong low speed torque and throttle response while enhancing high-rpm power.

At low speeds, the intake valves have lower lift and are open a comparatively short period of time during cylinder filling. At high rpm where breathing is critical, the valves switch to high-lift, long duration mode to deliver the best volumetric efficiency possible.

Both engines continue to use the 3-rocker VTEC system, which allows each of a given cylinder's intake valves to be controlled by its own low-speed cam lobe. (By comparison, with 2-rocker VTEC, both intake valves in a given cylinder are controlled by a single low-speed cam lobe). With different low-speed cam profiles for each intake valve, 3-rocker VTEC allows for staggered valve opening and lift, which promotes swirl in the combustion chambers, thereby improving efficiency. With better mixing in the cylinders, burn speed and combustion stability are improved.

When engine rpm reaches 4700 rpm (4950 rpm in the TL Type-S), the powertrain control module (PCM) triggers the opening of an electric spool valve that routes pressurized oil to small pistons in the intake valve rocker arms. These pistons slide into position to lock together the three intake rockers in each cylinder, which then follow a single high-lift, long-duration cam lobes. With the engine's intake valve lift and opening duration continuously adjusted to suit the operating engine speed, the TL benefits with a broad torque curve and superior peak power. The two engines feature different cam profiles, with the Type-S sharing the same higher lift and longer duration.

Originally Posted by SouthernBoy

Ford was using hollow cams 8 model years ago in the 2000 SVT Contour, and perhaps even as early as '98 for the same machine. So this is not new technology by a long shot. And the SVT Contour had beehive valve springs as well. Only thing it didn't have was a form of VTEC.. which would have been nice.

Originally Posted by Accord_V6_400m

Alright...

Didn't ask for a history lesson nor did I say we were the first or second ones to do this just that it could be a good idea.

Originally Posted by bigman

I would think that the cam would be longer since the block is based off the rl's block. My question is how much power could the cam upgrade give without anyt tuning. Or can the engine compensate for such a small bump in duration and lift.

Originally Posted by I Go To Costco

Was that necessary? If you didn't find SouthernBoy's response necessary, then just don't say anything. I'm sure you'll garner a lot of positive responses if you act like this in the future.

Anyway, if the RL cams are too long, wouldn't the TL-S cams be too long also? IIRC they're the same engine, save for the different exhaust system.

Originally Posted by sbuswell

i am intrigued by the cam swapping idea but i doubt there would be enough benefit without swapping the whole crankshaft.

Originally Posted by SouthernBoy

Ford was using hollow cams 8 model years ago in the 2000 SVT Contour, and perhaps even as early as '98 for the same machine. So this is not new technology by a long shot. And the SVT Contour had beehive valve springs as well. Only thing it didn't have was a form of VTEC.. which would have been nice.

Originally Posted by SatinSilverTypS

ford was also using the hollow cams in their late model taurus SHO {3rd gen SHO, from 1995 or 1996 (can't remember which it was now) to 1999 when they finally killed it}. they had NOTORIOUS problems with the cams snapping and spliiting in the SHO V8. i wonder if they ever fixed it. regardless, i'm sure the acura cams will be much better.

Accord_V6_400m - as you mentioned, using the RL cams had been tried and much more was involved than just swapping the cams. to see if these are just a dead swap you will probably need to find out if any of the other part numbers in the valvetrain match the tl part numbers. if not then they are most likely all RL parts and it wouldn't be a direct swap. this is just an initial guess though.

SSTS

Originally Posted by Accord_V6_400m

Just checked out the part numbers for all the TL's and all of the other parts are the same! Only the cams are different

Sadly this is only a dead swap for the 04+ TL everything else uses wider pulleys and belts. The only other car that matches the part numbers are the 7th gen. Honda Accords.

Originally Posted by SatinSilverTypS

well, i guess that it's a start. anyone who does the 3.5L upgrade for their 2nd gen has something to look forward to

SSTS

Originally Posted by Accord_V6_400m

Alright...

Didn't ask for a history lesson nor did I say we were the first or second ones to do this just that it could be a good idea.

Originally Posted by SatinSilverTypS

ford was also using the hollow cams in their late model taurus SHO {3rd gen SHO, from 1995 or 1996 (can't remember which it was now) to 1999 when they finally killed it}. they had NOTORIOUS problems with the cams snapping and spliiting in the SHO V8. i wonder if they ever fixed it. regardless, i'm sure the acura cams will be much better.

Accord_V6_400m - as you mentioned, using the RL cams had been tried and much more was involved than just swapping the cams. to see if these are just a dead swap you will probably need to find out if any of the other part numbers in the valvetrain match the tl part numbers. if not then they are most likely all RL parts and it wouldn't be a direct swap. this is just an initial guess though.

SSTS

Originally Posted by SouthernBoy

Question. Does anyone know if the '07 TL-S heads will bolt on to the TL engine block? Also, do the heads on the '07 TL-S preclude the use of headers like the '04-'07 TL engine does?

Originally Posted by SouthernBoy

Not a history lesson, friend.. just a point of interest. All manufacturers at one time or another come out with some great ideas that make there way into production machines. These ideas most frequently come from racing technology.

The 2000 SVT Contour was a peice of work with some outstanding components. I think Ford tends to be one of the better innovators when it comes to putting magic into street machines.

This in no way takes away from the Acura TL. The only real fault I see with the engine is the fact that Honda can't seem to pull itself away from belt-driven cams and interference engines. This is not rocket science and is not the best way to go.

Originally Posted by bigman

The difference between the type s torque and the regular is mostly due to the displacement being bumped up on the type s. The cams will probably help with off line feel and throttle response, but i think the work involved with putting them in is not worth the minimal gain.

Originally Posted by fsttyms1

Only if they change blocks and dont reuse the Stock 2nd gen motor.

Originally Posted by Accord_V6_400m

Natuarally, however don't forget that for some the appeal of hollow cams and reducing valvetrain mass is very inticing.

Anyway we'll see how they work in a 3.0V6 within a few weeks.

Originally Posted by bigman

I think some head work, and larger valves would benefit the 3.2 more then the hollow cams.

Originally Posted by bigman

I had an SVT Contour before i got the TL in 99. I loved the SVT more than the TL. It was cheaply made, but the little touches that made the SVT stand out and the rarity made me love it. Not to mention it was stick and oh so fun to drive. With full bolt ons and a 100 shot, i was running mid 12's and could out handle many a rear driver in the twisties.

Originally Posted by SatinSilverTypS

yeah true. i forgot that little fact.


SouthernBoy - yeah ford was using their own v8 in the SHO for the 3rd gen models for 96 through 99. (circa the "bubble design" taurus). that's why they sucked. the 89 through 95 SHOs had the yamaha v6s in them. fantastic engines those were. tell your friend to check out shoforum.com if he hasn't allready. there are alot of smart people over there. god knows he'll need them if he has as many problems with his SHO as i had.

Originally Posted by SouthernBoy

I think the only problems he's had have been clutch (he doesn't operate one like I do) and his A/C compressor. He has an after-market exhaust.