Plan - I'm replacing my cams with Crower 404's, Crane valve springs and retainers, installing AEM adjustable cam gears, and a VAFC to tune it afterwards (at a dyno shop). FPR already installed.

I understand the process, quite a few DIY's online, the disassembly part, assembly part, I have a valve spring compressor, setting the valve clearance, etc.

First off, I've heard that to keep your valves from dropping you should compress each cylinder as your working. Getting the hoses and adapters is no problem, and I bought a little air compressor. It produces 150psi and has no regulator. Since none of the DIY's note how at what PSI to compress your cylinders, or how much PSI is too much, I'm a little hesitant, although I think this should be fine, as 4 cylinder engines usually have a compression range 150-200psi.

Second question, I'm going to put these big cams in, put in adjustable cam gears, set the valve clearance, and then, assume its going to run well enough until I get to the dyno shop. My research has indicated that it will run like a Harley, unless I increase the idle to 1000-1100.

Please comment on these questions, and feel free to comment on my plan or any other small details you might think I've missed or might miss. I haven't really done any work on the inside of an engine before, although this isn't very technical.

Thanks in advance, this site always produces the best information, feedback, and advice.

Here's a good link to a DIY, although its on a SOHC. - http://www.sicracing.com/diy/d16-cam-and-spring.html

 

As a follow-up, since this thread is getting SOOOO much action , I'm trying to determine if there is any good reason NOT to install NEW intake and exhaust valve seals when doing a cam/spring install? They will be accessible, and seem easy to remove and install.........thoughts? $33 on Ebay for OEM complete set........

 

I would do it just for ha ha's. I mean, your right there and you won;t have to worry about it later.

 

I would also recommend to also move the piston to TDC in the cylinder that you are working on just in case the air doesn't hold the valve in place. 150 psi is fine for the cylinders. The force of compression is a lot greater than the pressure from a mini air compressor.

Yeah, it will run like shit. The idle will be nasty. I don't know if you will be able to get it to the dyno without at least a basemap.

And yes, replace the valve seals since the springs will be off.

 

Well, not being able to drive the car after doing this work IS a problem, I had not heard a basemap would be necessary from all my previous inquiries into this matter. I do have a PR4 ECU from Erick's Racing, but that's just their program + a 9,000 RPM limit, optimized fuel and timing, etc. I wasn't really expecting to get benefit from it before the cam install, and I was never planning on going over 7,000 rpm w/o new stronger internals (and if I'm in my engine that deep I'd do a lot more than just replace the rod bolts!). I know almost nothing about ECU programming, basemaps, etc.

 

bump for more help

 

a basemap will make the car run better until you can get it tuned

 

thanks, this I understood. What I don't know is really what that means (I assume its an ecu reprogram for larger cams) or how to go about doing it.

 

It is a chip with a 32k binary file containing all the engine parameters that are set to a certain value. A basemap is just a conservative guess on fueling and ignition timing to get the car to a dyno to have it tuned properly.

Is your ECU chipped? If so, pherable.net can burn you a program based on your mods that would get the car running and to a dyno.