can cam be changed when engine is in it's place?
Or should engine be removed?

Somebody sais, that rear cam seal is impossible to get seated correctly when engine in place. Is that correct?

What is correct procedure to change cam?

 

I changed the cam with the engine in the car ... but had to jack the engine a few cm. 1991 L98, btw.

 

What is this stuff between cam and block?

 

Looks like moly lube and CC cam lube on the lobes.
Why would you need to change rear cam plug in the block?

 

I've done that before too, but with a roller cam you need to check the cam end play. Too little and it will push the timing chain against the plate and put shavings in the oil. too much and it will bump around, and put shavings into the oil.

Usually, I install the cam on the stand, then check endplay, and adjust the rear plug until propper cam end play is achieved.

I have had luck numerous times with the aftermarket cam being "dead on" with the came that came out of the block, but I also had 1 that was too tight.

-- Joe

 

Its not a bad job, just take your time.
My trans was out at that time, so tilting the motor to get the cam past the cross member was not a problem.
Here is a pic of the cam hitting the cross member on my 86, some years the cross member is different.

 

Not me, i just checked Richard Newtons book "101 Projects for your Corvette" and there he says, that cam is almost impossible to get back when motor is in place. Because rear cam seal does not seat correctly and will leak. I assume he was wrong?

 

He's partially true. Like I said endplay is a big part of it. Theres a difference between a backyard mechanic, and people who actually blueprint the engines they build. checking, measuring, and making sure everything is in spec is part of propper assembly. Sometimes it "just works" and sometimes it just "blows up".

Over the years i've seen pictures posted by disgruntled members @ thirdgen.org of "bad defective parts that failed" when it was clearly the idiot who installed them who was at fault.

-- Joe

 

Joe, thank you for getting that point across.

This is exactly why I jump on someone here, when they unwittingly tell another member (who may only have some experience), and just simply claim -- yeah build up the engine DIY, you can do it!

That's really bad, thoughtless, downright irresponsible, and quite franky dangerous advice. In fact I'll go so far as to say that guy telling the other guy DIY is a flat-out azzhat.

And every time I tell them that, and say "Hey, will you be there to pick up the pieces after his engine goes, after you told him he could do it".....every single time that goes unanswered because they know damn well what I'm talking about. Of course they won't be there to answer for the $$ in damages.

Building an engine is NOT for the backyard novice on his daily driver. I challenge anyone to tell me different.

Thanks again for making it clear

 

I tell people all the time. Either learn and buy the tools to do it right, or don't do it. Especially on a daily driver. And just because some guy did something some way and it didnt blow up (yet), doesn't mean it's the right way.

Oddly enough, I got into an arguement with a friend last night over cam swaps. has over 100k on this motor in an fbody, wants to do a cam swap engine in car. I told him "Dan, first of all, even if the endplay works out, those cam bearings have had 100k on another cam. You might lose oil pressure in the first 10 minutes of running with the new cam. Not to mention, any metal shavings posibly in the babbit are gonna ruin your new cam. Do it right, or don't do it"..

-- Joe

 

I wouldn't say he is wrong. You need to know what you have to begin with!
When you install a cam the first thing is to have all the proper tools. One of the first steps in installing a cam is to check everything out first . Upon actually installing you will need to check end-play with a mag base indicator. I believe spec. was .012. This will tell you were that rear plug is located. This important for a few reasons, one is obviously location which then can play a role on timing chain, lifters etc.
IF it isn't leaking to begin with you should be able to put it together w/out changing it. HOWEVER, if the trans, and motor is not out it is that would be anyone's guess.
The cam is NOT impossible to get in or out. The condenser, radiator, fans, water pump, AIR, etc. etc. all needs to be out of the way for starters. Then, remove motor mount bolts lifting the motor up(if in the car) almost as high as it can go so the cam can clear the cross beam. .
This is a very condensed version without other issues such as installing rockers, push-rod and rocker geometry/length etc. IMO, The hardest part of this job is the dis-assembly and re-assembly of all parts needed to get it there.
From some of the questions etc. doen't sound like you have installed many camshafts/heads etc. Before leaping out there, you may want to have a closer look at all of this first.

 

You are right. i haven't change cam to small block never.
I have a "plan" to tune engine during next winter: Cam, Superram, headers. And yes, i haven't took a closer look to things yet. But i will. Just this question was the most important, because all other things i know, can be done with engine in its place.

Sure, i will familiarize myself before doing anything.

What hp:s are expected with those mods? I hope i could get 350 out of it. Now it is stock L98 -87

 

Doing the homework certainly will pay off in the end and will allow you to dodge the pitfalls.
Well first things first, what cam? Will there be any head work done?
HP at the crank or rear tire?
If all things are matched up good, heads (ported or preferably aftermarket) the 219LPE, 1.6 rockers, etc. I would suspect around 330-350ish RWHP. While there are other camshafts that would make more power, that is a proven reliable set-up that would be very drivable. This is a guess as each would be a little different.
Another point of interest would be how many miles on the current set-up?
IMO, if the motor exceeds around 60k or so I would at least consider re-ringing and bearings. Preferably freshening the entire bottom half, again this would depend on what you see once you get in there. While doing this may not be quick gratification, it is better to put together a good reliable motor.

 

I'm not sure yet what cam. And i think i will not make any head work for now. I want it very driveable, this is more important than maximum power. I don't want to lose low-rpm torque, so i think superram and some mild cam is ok solution? Any suggestions?

Engine has 90tmiles on it. I know, i should take it off and redone it. But i have another block waiting, and maybe i get it redone and sometimes, put it on, if this fails. Just do some practise with this old one, and maybe find a good combination?