Bigger cams - checking clearance on existing motors

[audifreakjim]

I have an Iroz in my ear about doing cams on my car 90 so I started talking to 034 about getting a set of CAT cams. Javad brought up a good point that the CC should be clayed when installing aftermarket cams.

I am not cracking apart this motor so wanted to get feedback on what people have done here. I am running Wiseco 8.5:1 pistons with intake valve reliefs, but nothing on the exhaust side. Head was surfaced on install, block was not.



I am thinking any of the hydro lifter cams should be fine, I would obviously turn the motor over by hand to check for interference while cranking, although that doesn't reflect what is going on at 8500 rpms bouncing off the rev limiter.

Thoughts?

[SEStone]

Pulling the head is relatively easy and not insanely invasive--especially with your V-band turbo stuff. All of the Cat Cams I have ever played with (admittedly for 1.8T applications) all really needed to be degree'd in anyways, so you're really out some coolant, a head gasket, a bunch of paper towels, and a couple more hours to do it right.

Edit: The way I figure, if you don't check and order some cams and throw it together, you're out $1k for some cams that will either not work/bend valves, or a bunch of work and screwing around degreeing the cams in to avoid the pistons, which is not ideal for performance and a pain in the balls to do after the fact. Do it right or don't do it at all.

[chaloux]

Why not just put the 1k into an 07k fund?

[audifreakjim]

You both are correct! I am at the limit of my fuel lines and pump anyways so it's just a can of worms. I only have patience for one more can of worms project on this car and I am saving it for an 07K

[chaloux]

You both are correct! I am at the limit of my fuel lines and pump anyways so it's just a can of worms. I only have patience for one more can of worms project on this car and I am saving it for an 07K

I hear you. The next major thing I do well be 07k. No big turbo sexy aan for this car...

[Hank]

Those Relief's look plenty big for any hydro cam IMO. The exhausts will never hit. I don't think there is even 13mm worth of distance from the top of hte valve to the head surface.

[audifreakjim]

That was my gut feeling too. I bet it would be fine, and I could degree the cams on another spare head in theory. Probably still not going to happen. I should just sell my extra set of 7A cams for the fund.

[Hank]

Cams are a pretty hot commodity really. I think you could sell them in 6 months or whatever and not take a bath.

[chaloux]

Gross. You should probably try to take a bath or maybe a shower in 6 months.

[Mcstiff]

Hank got lost

Those are from Nick's 200, and he is running basically the most aggressive hydro cam Cat sells. No dish on exhaust, and equal looking dish on the intakes. Do you have the spec sheet? we can compare with the JE's Nick has

Hank

[my2000apb]

ya wrong jim hhaha

[pilihp2]

I'm loling. Really hard.

[EDIGREG]

Hank loves baths

[audifreakjim]

Hank, the master instigator.

[mushasho]

Take 7A's and regrind...

Sent from my HTC One using Tapatalk

[Hank]

Hank loves baths

LOL. Damn shower head.

[GTJeff]

Obviously claying is ideal but I had good luck with the following procedure on a two valve motor with a centrally located spark plug. I'm sure it would be somewhat trickier on your 20V head.

For checking piston to valve clearance you could try using a zip tie like a feeler gauge. You need one long enough and the right thickness for your minimum valve clearance (50 thou intake, 60 thou exhaust or whatever.). You will probably need to bend the end of the zip tie some to get it to go the right direction for whichever valve you are checking. What you do is stick it down the spark plug hole and work it back and forth between the valve and the piston as you slowly and carefully rotate the engine by hand. I say slowly and carefully because there is the possibility that you could bend a valve doing this. You need to understand the geometry of where the minimum clearance would occur and aim for that point with the zip tie. As you approach TDC you will feel some resistance to pushing/pulling on the zip tie. If it sticks then you don't have enough clearance but if you can get it over TDC without it sticking then you are good to go.