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#1
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Intake camshaft removal
Now, I know that some of you have had to remove the EG33 camshafts at one time or another. Tomssvx, you had to do this once, didn't you?
What I'd like to know is the best way to remove the intake camshafts. And by best, I mean easiest. Ideally, I would like to be able to remove them by only removing the valve covers. I could see that it might also be necessary to remove the timing belt and camshaft pulleys as well. So, basically, is there any way to do this without pulling the engine? Thanks all. |
#2
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Do-able, yes
but it requires more than just removing the valve cover. Accessory belts, front timing covers (plastic) and cam drive belts, then valve covers (which also entail coil packs), and cam supports.
Not an easy job with the engine in the car. Why do you want to do this job? Todd (multiple cam and engine removal guy)
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#3
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I Just did my exhaust cam shaft on the pass. side. You will need to remove the timing belt to get the marks lined up correctly. The valve cover and the front half cap, see pic, that hold the front of the cams in place.
Important Make sure to install the maintance bolt onto the intake cam sub gear before removal. Remove the cam bearring caps and out it should come. Not that hard to do. this is a great time to replace the lower cam seal too. The timing gear does not have to be removed from the exhaust cam. Steve
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#4
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- Remove the accessory belts, crank pulley, timing belt cover, and timing belt. - Remove the spark plug boots, valve covers, and gaskets. - Remove the front cap for the intake camshafts (this is the little black looking "cylinder" right? It's also a cam seal, correct?). - What is the maintenance bolt that has to be installed? Is this a dealer-available service part? I haven't heard of it before, but apparently it gets installed in this step. - The timing should be marked on both the camshafts, right? Or do they have existing marks (similar to the pulleys, block, and timing belt)? - Remove the bearing caps. - Remove the intake camshaft. (And the following are just for my sanity) - Reinstall the camshaft. - Install new valve cover gaskets. - Replace spark plugs. - Reinstall valve covers and spark plug boots. - Reinstall intake cam seals, timing belt, t-belt cover, crank pulley, and accessory belts. Thanks again! |
#5
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There's no guarantee that this will result in loss of the non-interference setup, as I have never seen precise piston-to-valve clearance numbers. Either way, I could care less. So Todd, if you have any cam removal advice, please let me know. I think we could all stand to see a 255 - 260 hp N/A SVX, eh? |
#6
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#7
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1 mm more on the inlet will bring the both to 8mm. Of course the other reasion is, its cheaper to do one than two. Harvey.
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One Arm Bloke. Tell it like it is! 95 Lsi. Bordeaux Pearl, Aust. RHD.149,000Kls Subaru BBS wheels. 97 Liberty GX Auto sedan. 320,000Kls. 04 Liberty 30R Auto Premium. 92.000kls. |
#8
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And since the exhaust valves are open when the piston is rising, I do not wish to risk the life of the poor little guys. The intake valves are open when the piston is dropping, giving that diaphragm effect. The one thing that I did want to ask, especially towards the technically minded (like Harvey ), is if there are any other risks. For example, will the other internals have the appropriate threshold to allow another 1mm without breaking, binding, or stacking? Do I need to worry about replacing other parts with the camshafts? You know, the typical run-of-the-mill worries that come with any new performance parts. Oh, yes, I also wanted to see if anyone knew the stock duration on the cams. Is it possible to measure it using the cam lobes? Per this thread, it appears as though the intake duration is 236 degrees, and the exhaust is 244 degrees. Just curious, really... because the service manual gives a value for the valve lift that doesn't appear to be true (per this thread), so who knows if the duration values are to be trusted either. |
#9
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In increasing the lift, there are two ways to do it. First is to grind the cam lobe base circle to a smaller dia. This will increase the lift, but will also increase the follower clearance. For a small amount <1mm, the hydraulic lifter can take up the extra clearance. If more lift is required , a shim can be fitted under the lifter to take up the clearance. To go to a larger lift the nose of the cam has to be built up with weld to increase its height and reground to the same duration profile. This then may have the nose of the cam hitting the sides of the lifter well, as it turns. This area can be ground away to clear the nose ok. I have not looked at this engine to do this, and it would be best to let the cam grinder look at the head, to see how much clearance there is between the cam nose and the lifter well. Slightly stronger springs would be needed, but there is no point in using super strong springs, as they just stress the valve gear more than necessary. As I have allways said if you are going to run an auto, you need to maintain the same duration figures. If you are running a manual and low gearing, and don't use low rpms, you could add more duration to pick up the power over 4000 rpms, you will lose a lot of the torque below 3500, but if you use the gears in the box to keep the revs up, the duration could be increased to about 256 degs. Harvey.
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One Arm Bloke. Tell it like it is! 95 Lsi. Bordeaux Pearl, Aust. RHD.149,000Kls Subaru BBS wheels. 97 Liberty GX Auto sedan. 320,000Kls. 04 Liberty 30R Auto Premium. 92.000kls. |
#10
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Essentially, I would like to increase the lift as much as possible without having to change any other internals. If something like installing a shim (which sounds pretty damn easy) is required, I could go for that. Quote:
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#11
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To use the Auto box, you will need the low torque, as the gear box will allways use those low rpms. With a manual you can use the gears to stay in the higher rpms, so the bottom end torque is not so important. Harvey.
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One Arm Bloke. Tell it like it is! 95 Lsi. Bordeaux Pearl, Aust. RHD.149,000Kls Subaru BBS wheels. 97 Liberty GX Auto sedan. 320,000Kls. 04 Liberty 30R Auto Premium. 92.000kls. |
#12
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So Harv, what do you think would be a safe bet for an increase in lift? 1mm, or less maybe? Should the base circle be reground, or should the nose size be increased?
This post from NASIOC states that a lift size of more than 0.365" (9.27mm) on the 2.2 liter requires new valve springs. This is likely the same for us, since the EG33 is essentially the same but with 2 more cylinders. This thread on NASIOC talks a lot about how the valve lash needed to be adjusted multiple times (2.2 liter again, I believe). Once I do this, am I going to have to adjust the valves over and over? Can the valves even be adjusted on the EG33? If having custom cams is going to turn my SVX into a very high-maintenance machine that I must baby all the time, that will be my breaking point. I want to get better cams so that I can play with my car, not work on it all the damn time. Thanks again, Harv. |
#13
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I don't think the valve springs would coil bind, at the lift that we are looking at. They are using big lifts, 9.27mm is 2.27mm more that it has now. We are looking at 1mm. The EG33 has hydraulic lifters, so you don't need to adjust them, Harvey.
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One Arm Bloke. Tell it like it is! 95 Lsi. Bordeaux Pearl, Aust. RHD.149,000Kls Subaru BBS wheels. 97 Liberty GX Auto sedan. 320,000Kls. 04 Liberty 30R Auto Premium. 92.000kls. |
#14
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Grinding the cam for more lift.
There are two ways that the cam grinder can provide more lift. The first is to grind a new profile on the old lobe. The second is to build up the cam with weld, and then grind the new profile on that.
The first, is the one preferred by the grinder, as it is easier for them. They just chuck up the cam in the grinder, select the profile, ring the bell when finished. When the cam is done this way, the cam profile is smaller, so there is more tappet clearance. So you just have to adjust the tappets to take the clearance up. But we have hydraulic lifters, that can only adjust a small amount of extra clearance, probably less than 1mm. Larger lifts give larger clearance, so shims have to be fitted under the lifters. Not easy. The second way is to build up the cam with weld and grind the new profile, on it. This way the base circle is the same diameter, so the clearance remains the same. The lifters stay at the same position, and no shims are required. The pointed end of the cam, (the nose,) is now taller, so we have to make sure that it will rotate, without hitting the head casting around the lifter well, if so , the metal has to be removed to clear. As the exhaust cam has 8mm lift, it stands to reason that the inlet can use the same lift, with out having any problems, of hitting the casting, or binding the springs. 9mm may be possibly. This is the most likely way for us to do it. The 2.2 lt engines heads are completely different to our heads. Our heads are more like the WRX, twin cams over bucket hydraulic lifters, working directly on the valves. So it follows that what has been done, with camshafts on the Rex can probably be done on the SVX. I am not suggesting that we follow the same timing, as they have different objectives, but the lift problem would be the same. It would be good to research what they have had to do, to get the lifts. Harvey.
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One Arm Bloke. Tell it like it is! 95 Lsi. Bordeaux Pearl, Aust. RHD.149,000Kls Subaru BBS wheels. 97 Liberty GX Auto sedan. 320,000Kls. 04 Liberty 30R Auto Premium. 92.000kls. |
#15
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Thank you Harvey. All very good information to have. I will be performing a lot of maintenance on the SVX quite soon, and replacing the valve cover gaskets is one of them. I will be sure to let everyone know when I get the measurements for the lobe clearance, and also of course when I have the new camshafts done up.
I am also considering purchasing a spare engine, that I can build more easily from outside of the car. If this ends up being the case, I will be performing a lot more work than just camshafts. Decisions, decisions... AWD 5MT, or built N/A engine? |
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