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Old 11-16-2020, 10:49 PM   #1
rallybrick
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Default VX cam or K cam? (245/LH2.2/M46)

Been a while. A few months ago, I got back my old 86 245DL (which I had purchased in 1995).

This is a bit of a project car I'm doing with my two young sons (neither are driving age yet -- 8 and 11) who are turning out to be car nerds. Over the past few weekends, we pulled the M46, tore it down to install new synchros, and put it back together with great success. Now that the bad 2nd gear synchro is gone, it's fun to drive again and we're picking away at other projects. I have a bit of a parts hoard due to having project 240s and a race car way back when. There are a bunch of bits we could put on together.

The car's drivetrain is an unmodified 86 B230 running lh 2.2 with 375k miles on it and an M46. Never been torn down (or the head pulled). It's always been a solid runner. I have the following laying around -- what do you think we ought to use? We're mostly running stoplight to stoplight in the city and hooning over the hills to the post office.

VX Cam (NIB)
K Cam (used)

MVP aluminum adjustable timing gear (NIB)
Avalanche/Dale steel adjustable timing gear

Would like a little more umph around 2500-3000 RPM (or higher). I used to have all the bench racing specs and timing info in my head, but they've long since vanished. I'm leaning toward the K. Either needs to be able to pass smog in CA.

Thanks!
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Old 11-17-2020, 01:49 AM   #2
redblockpowered
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If I had both laying around, I'd try both just to see. I think I'd start with the K cam, though it may be tough to pass emissions like that.
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Old 11-17-2020, 07:18 AM   #3
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Not sure how 2.2 responds to cam changes as we do not have it here
I would start with the K on the factory timing gear and see how you like it. If not so keen on it give the VX a bash.

Hold onto the original cam incase you need to drop it back in for smog
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Old 11-17-2020, 07:27 AM   #4
Jussi Alanko
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I would use a mild aftermarket kam, with about 250degrees at 0.050 and something about 12mm lift.

Then when yours emissions is checked, just change the original cam.
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Old 11-17-2020, 11:37 AM   #5
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A K-cam likely won't pass CA emissions but is more fun.

I would recommend advancing the ignition and cam timing some with the K cam as it will get you that 2500-3000rpm bump you seek. Advancing both helps you with the rough idle and lack of off idle power you get when running it straight up in a lower compression motor like the B230F. Advance the cam 2-4 degrees depending on what feels right to you and the ignition as far as you can get without ping on your desired grade of pump gas. You won't make as much on the low end but the motor should just pull itself gently into the power band. At which point the fun starts. When my '89 had a K cam it pulled nicely from 2k to redline after some experimentation.

The VX will pass CA emissions. Just put the timing cover on to hide the adjustable gear during the visual inspection. It won't be as fun as the K when you wring it out but it would be better for a daily driver once you dial in the cam timing.

Really the easy way is just to swap the M cam back in and drive the car a bit so the ECU knows what is going on before the test.

I wish CA would just let you modify OBD 1 cars to your heart's content so long as it passes the dyno test. If anything we should also be dyno testing OBD II cars as it isn't hard to cheat with all electronic tests (VW taught us that).
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Old 11-17-2020, 05:52 PM   #6
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With stock compression ratio, this is a no-brainer for the milder VX.
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Old 11-18-2020, 03:23 AM   #7
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If you don't mind POTENTIALLY doing a camshaft swap more than once, I would definitely slap in the K cam first because it'll be faster and more fun, even if the low rpm torque off idle takes a large hit. As mentioned, more compression would be ideal, but that might be best for another time when your boys want to help pitch in with costs, hah.

When installing the K cam, set the valve clearances on the looser side of things, .018-.020" to make the camshaft "smaller" and have slightly less duration. This will improve idle quality, emissions and low rpm torque at the expense of some high rpm power that you don't really care about. I also would advance the camshaft timing 2-4 degrees and advance the ignition timing to somewhere around 16 degrees at idle with the vacuum disconnected. It might even like more than that, but it may not. Listen for detonation, but with the K cam it might even be ok at that point on regular octane.

Give it a whirl and see what you think! Also do a seafoam or similar soak on the pistons overnight when you do the next oil change to clean any carbon build up from the piston rings that is likely reducing your compression. Get some good fuel system cleaner in the tank to try and clean up the injectors and intake valves as well.

While you're at it, remove the pre-heat flapper and route the pre-heat hose to cold air at the front of the car somewhere for slightly more top end pull and power on the highway.

The VX is definitely an upgrade from the factory M camshaft, but the one experience I have with it did not leave me impressed(1986 244 AT). I only compared it to the T cam that was, relatively speaking, a torque monster. I think I liked the T cam better, even though it didn't pull as much at high rpm(I had set the valves around .012" with the T cam and retarded it 4 degrees). The VX in comparison just felt flat and meh. I never made it to the drag strip with the VX in it, but the T set up like I mentioned was good enough for a 17.3s 1/4 mile compared to the M cam's 17.6s when set up the same way.

Try them all if time and patience permits! You may or may not pass emissions testing with the K cam set up loose and advanced a bit. We don't have as strict of emissions testing up here, but I have heard that advancing the ignition timing isn't ideal for that, so you'll want to retard the timing to help heat up the cat as opposed to running it more advanced.

Quote:
Originally Posted by Jussi Alanko View Post
I would use a mild aftermarket kam, with about 250degrees at 0.050 and something about 12mm lift.

Then when yours emissions is checked, just change the original cam.
He has the VX and K to choose from. With a stock, unopened engine, a 250 degree duration camshaft at .050" of lift is too large. You need more compression to make such a camshaft be a good choice. For reference, according to Shoestring's MUCH APPRECIATED handiwork, the K's intake lobe has around 240 degrees at .050" and the VX's has around 232 degrees. A stock M cam has 196 and the T cam 212.

Quote:
Originally Posted by spock345 View Post
A K-cam likely won't pass CA emissions but is more fun.

I would recommend advancing the ignition and cam timing some with the K cam as it will get you that 2500-3000rpm bump you seek. Advancing both helps you with the rough idle and lack of off idle power you get when running it straight up in a lower compression motor like the B230F. Advance the cam 2-4 degrees depending on what feels right to you and the ignition as far as you can get without ping on your desired grade of pump gas. You won't make as much on the low end but the motor should just pull itself gently into the power band. At which point the fun starts. When my '89 had a K cam it pulled nicely from 2k to redline after some experimentation.

The VX will pass CA emissions. Just put the timing cover on to hide the adjustable gear during the visual inspection. It won't be as fun as the K when you wring it out but it would be better for a daily driver once you dial in the cam timing.


Quote:
Originally Posted by shoestring View Post
With stock compression ratio, this is a no-brainer for the milder VX.
Well, it depends on your goals. The K will be faster on a drag strip. Haha. The VX will likely have a better powerband for a 3.31 rear end car with stock compression and stock engine management than the K, I agree. I would still try a K cam out over a VX though as the VX felt so darned bland to me when I tried it and the joy of a powerband that keeps climbing as the rpms rise makes me smile.

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Old 11-18-2020, 09:42 PM   #8
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When i had the 1988 245, i tried A, B, and V.
I liked the A cam best.
In the 1983 with B23 (10:1) and ms1, K cam.
In newer cars, VX.
It all depends. Try a cam. Mess with it. You won’t see a big difference, but getting a somewhat normal cam in there is a good start.
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Old 11-22-2020, 11:59 AM   #9
rallybrick
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Thanks all, esp. Kyle and Shoestring -- appreciate all the info you've put up over the years.

I'm thinking I'll try the K-cam with the settings Kyle recommended first. I have the valve tools, but no shims laying around, so I may throw it in there and then order a shim kit from IPD and adjust it properly once it arrives. Maybe having the boys do cam swaps and document the actual performance changes will be the fun thing to do at Christmas break. Is there a Scout merit badge for that?

I might use the MVP gear (see below) for ease of cam timing change for the time being until we really nail it down, as I recall that long term the similar IPD version suffered due to the steel bolts eating the aluminum. Thoughts on this long term?

Good reminder on the Seafoam trick. I did that years ago, but can't really get away with it in my current neighborhood.

I hate having to swap things when testing comes around. I have 5 cars at the moment and tend to forget what needs what before these bi-annual events, then I get caught off guard. The good thing is that this 245 is not a DD, so if it sits while needing work, not the end of the world.

Quote:
Originally Posted by spock345
I wish CA would just let you modify OBD 1 cars to your heart's content so long as it passes the dyno test. If anything we should also be dyno testing OBD II cars as it isn't hard to cheat with all electronic tests (VW taught us that).
I have a 2.5l B21FT stroker, ported and polished 531 with T5 cam (SAM), ported matching exhaust manifold and big turbos sitting in pieces in boxes while my 82 242T still has a stock 398 with a Mitsu 12c on it because I'm shy of messing with emissions these days. And yet I had an '04 Subaru Forester 2.5XT that was a factory demo car that had been tuned by ESX and was like no other turbo Forester I ever drove (it was known as The Beast), but never had any issues with ODB II.
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