I am just curious how much I should expect to pay for a cam regrind of 95' Quad I/E cams to HO specs (or maybe even a little more aggressive). Also, if anyone knows of a shop around here or even online that will do this, it would be much appreciated. Thanks.
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"Youth in Asia"...I don't see anything wrong with that.
Crane will regrind them, I paid like $170 I believe for my single OHV cam.
fortune cookie say:
better a delay than a disaster.
hmmm...Sounds like I should have them regrind the intake cam and then just find a HO exhaust cam...Thanks Josh.
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"Youth in Asia"...I don't see anything wrong with that.
Just keep in mind that high lift cams will not fit inside the 2.4 cam housing without modification.
- 93 mph in the 1/8 mile
Member of J-Body Of Michigan.
If its a reground cam it should work with the 2.4l cam towers correct.
Skilz10179 wrote:Just keep in mind that high lift cams will not fit inside the 2.4 cam housing without modification.
I know... I recently picked up another 086 head that cam with 95' cams and 95' towers for a manual. All I will have to do is just drill and tap for the CPS since the casting of the top half of the tower already has the provision for one.
Paul Tjepkes wrote:If its a reground cam it should work with the 2.4l cam towers correct.
No they won't. The 2.4L towers don't have lifters wide enough to support .410" of lift. 2.4L lifters are 33mm opposed to the 2.3L lifters which are 35mm.
You might be thinking of a stock regrind, which would make your statement valid...but I'm changing the profile of the camshaft, so larger lifters are necessary.
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"Youth in Asia"...I don't see anything wrong with that.
so your using the 2.3l ho cam to regrind or your grinding your stock 2.4 cam to ho specs?
if you grind a 2.4L cam to different specs it will indeed fit in the 2.4L towers, no mods needed.
_______________________
** Flat Broke Racing Inc.**
^ Correct.
-Although most thrwo codes from what I have seen @ idle.
My Cav
I give up...
i'm buying a VW those people love trees, so they should love eachother too... "Andy"
TwistedMotorsports wrote:if you grind a 2.4L cam to different specs it will indeed fit in the 2.4L towers, no mods needed.
A couple things
1. I would be using the 95' Quad 4 cam as I first stated (Doesn't matter)
2. I really don't care if it will fit (even though with .410" lift and 212° duration, I am 99% sure it won't)...The ld9 lifters barely fit over the 086 springs as it is. So I have multiple reasons for using the 95' towers/lifters anyways.
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"Youth in Asia"...I don't see anything wrong with that.
Well...forget the whole 95' cam tower deal. I just measured the lifters, and they too are 33mm...oh well.
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"Youth in Asia"...I don't see anything wrong with that.
TwistedMotorsports wrote:if you grind a 2.4L cam to different specs it will indeed fit in the 2.4L towers, no mods needed.
To have a 2.4 cam ground to the specs he wants they would first have to add matierial to the cam (welding onto it) and the grind it to spec, .41" of lift it too tall to spin in a stock 2.4 cam housing.
- 93 mph in the 1/8 mile
Member of J-Body Of Michigan.
^ He is right.
Also, why not just run the biger lifters? there better, and made to run the higher RPM.
and with HPT you can ditch the cam angle sensor, besides above somthing like 2800 RPM the computer goes to batch fire anyway. (like a old LG0\LD2)
to in theory, to run HO/W41 cams all you would have to do is get a HO exhasut tower for the cam, and a 95 and up intake tower and have the lifter holes punched out for the larger lifters.
just an idea.
Chris
'02 Z-24 Supercharged
13.7 @102.45 MPH Third Place, 2007 GMSC Bash SOLD AS OF 01MAR08
Many inaccuracies here....
Material does not necessarily need to be added to get .410 lift out a 2.4 cam, The base circle cam be ground undersize to get there also, but lifter would need to be shimmed for proper preload.
Ditching the cam sensor with HP tuners would stick the car in batch fire all the time and you would really never notice the difference, which makes the first half of that idea correct. But the car does not switch over to batch fire at 2800rpm with the stock PCM. Only cheap aftermarket controllers with weak processors do that because they are not fast enough to run any other way.
The only time a stock PCM goes into batch mode is extremely low rpms (because it quits opening the injectors in sync with the intake valves opening or even in rhythm with the pistons at all) or cam sensor failure.
HO2.3 cams can hit the inside of the cam housings in a few small places, but this is because of the width of the lobes. 2.4 lobes aren't as wide and therefore may not hit. Although some 2.4 housings differ inside and some crash majorly in many places, while others hardly hit at all.
With high lifts (i.e. .410") the distance from the center of the cam to tip of the lobe is = or greater than the distance to the edge of the 33mm lifter when that lobe is touching it at the high point. With the wider than most lobes of the 2.3/2.4s, compared to most engines, this means that most if not all the lobe actually runs over the edge of the lifter.
This situation happens on stock 2.4 cams w/33mm lifters too, but its only a small percentage of the lobe so it makes no difference. Once over 50% of the lobe goes over the edge, rapid cam wear will begin. This is because the lifter is a sharpened edge of hardened steel that basically cuts the lobe off a little at a time.
35mm lifters should be used with more than .375 lift.
sig not found
Quote:
The only time a stock PCM goes into batch mode is extremely low rpms
How low? Many of the OBDI ecm's use a "stall saver" mode which will be activated below an adjustable threshold, usually between 400 and 500 rpm.
Quote:
Ditching the cam sensor with HP tuners would stick the car in batch fire all the time and you would really never notice the difference,
I wonder if some of the guys using what I consider very large injectors would be able to do it if the injectors weren't fired sequentially.
-->Slow
slowolej wrote:How low? Many of the OBDI ecm's use a "stall saver" mode which will be activated below an adjustable threshold, usually between 400 and 500 rpm.
That is exactly what I was referring to.
Injector pulses are not indexed to rpm in this mode.
quote=slowolej] I wonder if some of the guys using what I consider very large injectors would be able to do it if the injectors weren't fired sequentially.
That situation would be worse since in batch fire mode each pulse would be half the time of sequential and I am guessing you are saying this in relation to injectors that are too large for a clean idle at the bare minimum pulsewidth. If minimum is too long half minimum is still not attainable so no help.
Worse yet, in batch fire with huge injectors, high rpm fueling get erratic because of the huge volume and pressure spikes in the rail when multiple injectors open and close at exactly the same time.
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protomec wrote:
Material does not necessarily need to be added to get .410 lift out a 2.4 cam, The base circle cam be ground undersize to get there also, but lifter would need to be shimmed for proper preload.
Of course that is true, but in order to do that, you would have to grind down at least .031" to retain the same profile as a HO cam. If you go too far, you risk the chance of the lifter shaking in the barrel because it has to travel farther out of the barrel, since the 2.4/2.3 lifters aren't very long, in contrast to many of the v6/v8's and I think the 2.2L OHV as well. Definately not a great choice for high reving.
I would personally go with the tried and true method of using the 2.3L lifters
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"Youth in Asia"...I don't see anything wrong with that.
We're on the same page, protomec.
So the warning is, if switching to batch fire mode pay closer attention to your injector sizing. Close to ok minimums with sequential firing are not going to fare well with batch fire.
Next Q, regarding the cam. 2200 roller cam lobes are retained on the cam core tube with an interference fit. The cam is not a single piece of chilled iron or steel. With GM moving to this technology in other engine families, are the 2.4 cams manufactured the same way? I'm betting no, but if they are it can be important not to make the ramp too aggressive or to remove too much material from the base circle. You don't want to jeopardize the interference fit at the lobe.
One more reason to use the 2.3 lifters?
-->Slow
i need to dig out my GM books, i was pretty shure that it was SFI at low rpm and went to MPFI at high RPM......
Chris
'02 Z-24 Supercharged
13.7 @102.45 MPH Third Place, 2007 GMSC Bash SOLD AS OF 01MAR08
