knox839

Hello Ted B, I changed my cams to kelford 272 with bc springs. Now my turbo setup is gtx3076r gen2 with atp .82 ar evo flanged turbo housing with oem turbo manifold. Car is really fast on straights but spool is not good. Full boost is around 5200rpm which 22psi. Can you advise me cam gear setting to have better spool and mid range torque. I accept to loose some hp at top end.

Ted B

iTrader: (6)

For the standard Kelford 272 cam set, you can try retarding the exhaust cam by 2 degrees. That should help spool and midrange response, but I suspect that turbo setup will always have slow spool.

knox839

thank you for fast reply and help. approximately how much rpm do you think I can gain on spool to full boost?

sumopower87

This seems like the thread to ask all the cam questions. Definitely glad I stumbled upon this one. ​​Thank you for the guru that is keeping this one alive. You are much appreciated Sir.

So I have a freshly built 2.2 4g63 motor. And we are running into a bit of a conundrum.

The important details:
I'm using the Evo 9 head gasket (yes modded ports).
English Racing Oil Pump Gear (retards timing 2 degrees).
Kelford 272 cams.
Kelford adjustable cam gears

My buddy and I have been trying to catch the timing for about 2 weekends now.

It would be greatly appreciated if someone could assist with providing details as to how we going about setting the timing with the English Racing Gear + Kelford 272's + Kelford adjustable cam gears.

Greatly appreciated in any feed back.
Sumo
​

Ted B

iTrader: (6)

The English Racing website states the gear retards the cam timing 2 degrees, which means both gears need to be advanced by 2 degrees cam timing to compensate. Feel free to contact English Racing via email to confirm this as cam timing and not crankshaft timing. As far as any other cam timing adjustments, we need to know the turbo size and the application.

sumopower87

Very much appreciated Sir!

Currently I have a Turbonetics GTK-550 Turbo bolted up to a ETS T3 Manifold, gated with a VTA Tial 44mm.
The exhaust makeup will be a custom 2.5" O2 housing off the turbo, tapering to a 3" JMF downpipe with 3.5" straight to the rear.
Application would be for mainly road racing/auto x with the occasional drag race.

Ted B

iTrader: (6)

The standard Kelford 272 is a bit limited in effective duration for best power with this displacement and turbo, but it is a good street cam with good spool characteristics. For this combination, -1/-2 might help a little upstairs without sacrificing spool.After advancing both 2 degrees to compensate for the oil pump gear retard, the net cam timing would be +1/0.

RS200

iTrader: (1)

Since Ted B is on a constant roll, what would you do for settings here for a mid-range monster?

-2.0L Evo123/DSM block with 8.6:1 compression
-Well-ported cylinder head, stock valve size
-EFR7670, twin-scroll IWG .92 housing, Morrison T4 TS manifold, full 3" from the turbo
-Jun 264 cams w/ adjustable cam gears
-Stock/ported IM

I'm guessing 0/0 but wouldn't mind some additional top-end.

Ted B

iTrader: (6)

I've been on a roll here for 18 years.

The JUN 264s are too small for your application. The effective duration is very short, and the valve lift is insufficient to make use of a "well ported" head. It will be civil and run fine, but this cam set is really intended as an upgrade for an OE head, turbo, etc. I suggest swapping for a GSC S2 and a retune. Meanwhile, you can try +1/-1 to fatten the midrange.

RS200

iTrader: (1)

Oh gosh, I just realized. The 264 is the only 4G63 cam I know of that an actual duration figure has never been released or measured. Even the cam card is extremely vague. I ballparked it around 228/228 @ 1mm a while back; they absolutely require aftermarket valve springs and lope pretty good. Based on what I saw, it was very close to the Kelford 272 in duration, but at 10.5/10.5 on lift compared to 11.0/11.0. The Jun 272 is right around GSC S3 territory at 235/235, and their comparative powerbands match up very well despite the lower lift on the Jun 272, relative. Both the Jun 264 and Jun 272 centerline at 110/115.

Ted B

iTrader: (6)

The OE ports cannot take advantage of anything greater than around 10.5mm lift, but a ported head can, and will make more power with more area under the curve. The JUN 272 gives 235 deg @ 1mm, but still with 10.8mm lift, which makes it a good fit for an OE head. The JUN 264 likely gives 226-228, with an intake LC of 110 and LSA of 112.5, which puts it roughly on par with a Kelford 272, but not as well timed (IMO). The ramp rates are aggressive (which I like), hence the necessity for aftermarket springs. It's just that advancing that intake cam to bolster the midrange closes the intake valve too early for best performance with a larger turbo. Just my $0.02.

RS200

iTrader: (1)

I came across flow numbers for a stock port cylinder head, it's actually incredible how the 4G63 ports just die around 9.0 to 10.0 mm of lift. A well-ported head carries into the 11.50 mm range pretty well, though: http://users.erols.com/srweiss/tablehdc.htm#MITSUBISHI
I had my choice on a great deal between the Jun 264s and Jun 272s and despite the age of the grinds, I trusted their machining more than any cam maker. Jun cams were the hottest cam in the world in 2005 (heck, the current FP Black record holder ran it with Jun 272s). The 272s are just huge and weren't the right choice, and I was fine with the 264's lower lift to get the velocity going at lower RPM to help the threshold boost response. I guess 0/0 and a kick-*** 4,000-6,000 range is the best I can hope for, but it should be a lot of fun while I'm losing those races.

VictorGarage

Ted, i am changing to solid SME head with this spec



what is your recomend setting

knox839

Quote:
Originally Posted by Ted B
For the standard Kelford 272 cam set, you can try retarding the exhaust cam by 2 degrees. That should help spool and midrange response, but I suspect that turbo setup will always have slow spool.

I asked again, sorry if I bother you.
thank you for fast reply and help. approximately how much rpm do you think I can gain on spool to full boost?

sumopower87

Intresting, thank you for the advice. Would a fully port and polished head with upgraded stock sized valves yield any additional advantages? I have a Curt Brown spec'd head.

If you have any recommendations in mind, would there be a specific cam you would recommend? I'm only really familiar with the GSC R2 cams and the S3's, but wasn't sure if the S3's would be overkill.