Compression - Toyota Nation Forum : Toyota Car and Truck Forums

SupraTuned · 09-05-2009, 02:41 PM

I don't know guys, I have checked my measurements many times already from having the block and head done, and I am right at stock tolerances with my head gasket. It just seems that she doesn't have as much as I was used to. I did only drive it for about 2 months before I ripped it apart though. I can mash the gas in 3rd at 20 25 mph to the floor and it really doesn't move much until it gets to about 2500 rpm or more, or when the turbo spools. I also only shift at about 1500 rpm when driving, so that could be it as well. Maybe its just me, but she feels kind of sluggy. I checked the tps calibration, checked for boost leaks, and the compression test checked out perfect. Maybe I am just not used to it yet. I have been driving non turbo cars for about 7-8 months since I tore it apart, maybe I am just not used to the low compression until boost? Don't know if it matters, but I have 3" all the way back from a titan downpipe to a magnaflow muffler. I am not sure if there isn't enough back pressure. I thought these cars liked open exhaust though. I don't know. Any other suggestions? Maybe something I forgot to adjust? Or do I need to adjust my brain?

I also forgot to mention that I did a 15 second valve grind with medium grit (wet mix) and had the camshafts polished. It kind of sounds like I have a bit of a click in my valve train now. Would this change my duration enough to crap on my powerband? I am also getting slight cam noise, it isn't very loud, it fades in and out. I think maybe I should have measured for shims. You can hear it here. When I put the camera in the middle of the valve covers, you can hear it below the clicking of the injectors.

You Tube

Jeeves · 09-08-2009, 06:35 PM

Well, when any head work is done it's pretty standard (at least in my book to measure for those shims. It's a great time for them to get out of spec and need a little up/down adjustment and it's a pain in the ass at most any other time. It's not too hard to pull a valve cover and slip a gauge under there and check. I hear minor noise but as always cameras being cameras, headphones being headphones and so on and so forth it's difficult trying to deduce one noise from another.

For me, a lot of it is the compression in the 7M. The low end torque just isn't to be had like it is in many other (often newer) vehicles. Toyota seems to like it that way where as other brands seem to like to leverage more gearing to their advantage to give the impression of torque.

SupraTuned · 09-08-2009, 09:42 PM

Thanks Jeeves, I appreciate the response. I think it is just me as far as the sluglieness goes, because I vaguly remeber driving it home and wondering if something was wrong with it. One of the casual aquatices I knew at the time had one new and said that was just how they were. She does scoot good when you hit the right powerband though. And as for the shims, your right, I am at my retourque point right now so there couldn't be a better time to just meausre and get some. Thanks for the input! I always like a strong opinion. It helps.

Jeeves · 09-09-2009, 12:42 PM

The last thing you'd want it to do is be too loose and toss a shim then destroy a bucket.

SupraTuned · 09-10-2009, 04:48 PM

Nope, you are exactly right. I really don't need that right now, especially after all the money I just sunk into her. Other then the light noise, she runs like a top. The sound goes completely away after it fully warms up too. But I don't like it either way. I don't want to have to do a full head job or buy a new head right now, so as soon as I get to doing the re tourque, I am going to do shims as well. Not to hijack, but does anybody know how to reach the front head bolts without removing the cams? None of my craftsman sockets are thin enough to fit between the cam and the head. I have arp studs, if that is any needed info. I know there was something a while back I saw about a slim socket? I can't find one though.

Jeeves · 09-11-2009, 09:41 AM

I use a craftsman 12pt, deepwell socket and I can hit all my arp's. The biggest trick on some of them is rotating the cams so that they line up with notches for the socket. I also find that a pair of pliers to pull the socket out may be needed.

Especially THIS guy:
[img]http://xd.**********s.com/uploads/a176fdd76e.jpg[/img]

SupraTuned · 09-11-2009, 03:06 PM

So it can be done with a normal deep well. Thats good to know, I was having trouble finding a low profile one. I have many of those floating around. I appreciate the input. I will make sure to rotate to fit. Better then taking the cams out again! Thats almost to the point I was at becasue I really didn't study it too much when I had the engine apart. Thanks!

Jeeves · 09-14-2009, 10:54 AM

Nah, they're tight but they can all be had. Craftsman has been the most consistent for me. All the others I've seen are hit and miss. And naturally due to the shape of the nuts it has to be a 12pt.

SupraTuned · 10-04-2009, 10:47 AM

Sorry, I had to resurrect an old post. Anybody do the Yammaha/honda shim thing? How do you think they hold up. My dealer wants $13 a piece for them. I need 16. That translates to over 200 bucks. I don't think so.