Well here is the situation, I have the heads off and I am thinking about getting them ported (almost definately). Now the real question is, the cam, I want to put one in, but I dont want to pull the engine. It was rebuilt about 30K miles ago. Do I really have to replace the cam bearings. The cars not gonna be used for racing I just want it to pretty quick. This is, with a 69, riviera G.S. thanks, will
That is exactly what I wanted to here!!! All right there is another question alright this may seem silly, but is it a must for me to replace the lifters and springs even if there is no apparent wear. thanks again , will
Will, You MUST use new lifters with a new cam. They have to break in together. The valve springs should be matched to the cam. Your current springs may be useable depending on the cam you choose. Best advice is to ask the manufacturer you get the cam from. If you buy from TA Performance, they can tell you if your current valve springs will do the job.
I had a fealing that I should get new lifters. How hard is the cam to swap out I already have the engine pretty disassmbled. Do I have to do special measurements for clearances or do I just put it in and button it up. Also what assembly lube should I use? Thanks very much, will
Assembly lube will come with any new cam. You can get it from anyone that sells cams, or any speed shop. You coat the cam lobes and bottom of each lifter. A pint of GM Engine Oil supplement (GM part # 1052367) added to the oil is a good idea. Any cam should be degreed in to be sure it was ground right, and that it is installed the right way. That requires a degree kit commonly available in Jegs or Summit catalogs. Yardley has the cam degree procedure on his website. The only other thing you need to be concerned with is oil pump prime. Anytime you disassemble the timing cover, you should disassemble the oil pump and pack it full of vaseline. If you do not, the pump may not prime, and pump any oil. Cam break in is extremely important. 2000 RPM for 20 minutes when you first start it.
If you're going that far into the engine why not change them? Unless you already have them, and depending on milage (30K is high to me), I would change them out with TA's dual back grove ones. And if you're going with a stronger cam why take the chance of cam bearing whipe out? This can be done with the engine in the car. I have done it twice.
Varying the rpm is preferred to just keeping it at a steady rpm, the changing rpm changes the spray pattern on the cam form the rods and just helps for better oiling. If you are going to a larger cam,which you are, from a stock cam, you could run into cam bearing issues after the change. The bigger cam with stronger springs will put more load on the bearings, this may cause you a proble,. Jim Burek
Sorry for butting in here, but it is relevant to the conversation... Assuming I have stock stage1 valves and springs, would I have to change springs if I were to go to a mild cam such as the 236/238 Scott Brown cam or the TA 288-94H? Also, the motor will be in the car. So I may not be able to install new bearings. It's got 72000 miles on it. Thoughts?
Jim Vary the RPM on cam break-in, within what range? Also Adam did you enjoy the game? I liked the Eagle game also. Dave Berry:beer
I have used the 226/238 with stg-1 springs on several occasions, no problem. If your original stg-1 springs are old, you will want to change them. Jim Burek P.A.E. ENTERPRISES
It's not reallthat critical, I usually fire up the engine and take it to 2000 to 2200 for the first few minutes, then vary the rpm between about 1700 and 2800, no real particular variation here, the most important part is to not let it idle. Jim Burek
How long before you can let the engine idle? Also Once I get the cam out is there any other prep work other than changing the bearings if needed? also do new cams come with pretty detailed instructions on how to install them or is there a universal method? thanks, will
Will, I have never seen any instructions other than the cam card w/ spec's when you buy a cam. Make SURE you are 100% certain of what needs to be replaced, springs, cam bearings, etc. It is a recipe for disaster if you go in and don't have everything done that is required to make the engine live with a new cam. Buicks eat cam bearings VERY easy so make sure you are 100% sure of what you are doing before digging in there. Ask as many questions as you need before starting. There is an unbelievable wealth of knowledge on this site! Brian :Smarty:
