Should i replace cam? 172K

[87we410877]

I pulled the motor apart with 172K miles on it. Diesel oil was used from day on in 1987 so it had all the zink and other additives. Everything in the motor lookes absoulutey awesome. The cam along with the lifters and the rocker arms were all in exellent shape. Perfect circles on all the lifters but nothing actually purtruding deeper than the surface. Cam also looks very good. Heres my question. Im doing a stock rebuild/freshen up. Shoud i replace the cam and lifters or will i be running into problems since it ran fine as it was and had no issues? I will be replacing the timing chain and tensioner no matter what. Any thoughts would be great and also where to get stock replacement parts if needed. Thanks again!!!!

 

[broke1]

Id put a baby roller in it.I think there is one out there thats like 194*.Id definetely go roller and forget about it.

 

[bison]

If it aint broke dont fix it, unless you want to go roller. Even then plan on shorter valve spring life. Personally id keep it the way it is and itll probably last much longer.

 

[87we410877]

If it aint broke dont fix it, unless you want to go roller. Even then plan on shorter valve spring life. Personally id keep it the way it is and itll probably last much longer.

Thats what i was thinking. Im keeping it stock down to the 2 clips holding the alternator wire in place on the bottom front timing case Whats the stock spring pressure supposed to be and at what height? Ide like to at least check that. Thanks.

 

[cabech984]

what oil were using throughout the engine's life, rotella t? If it worked for you, I may have to give it a shot!

 

[87we410877]

I'll have to find out. I think it may have been rotella. I bought the car from the original owner about a month ago. I'll let ya know.

 

[Underboost]

Stock replacement parts.

nos4gn Buick Grand National Parts Home Page

 

[87we410877]

Thankyou!!

 

[bsdlinux]

Go roller cam and use Royal Purple and be done with it

 

[87we410877]

Roller cams are not stock even tho it would be 100 x better, its going back to stock. I have a roller in the other car.

 

[bison]

Thats what i was thinking. Im keeping it stock down to the 2 clips holding the alternator wire in place on the bottom front timing case Whats the stock spring pressure supposed to be and at what height? Ide like to at least check that. Thanks.

Stock springs are around 70lbs @1.75inches. Yours are probably less than that at this point. Someone correct me if im wrong. Id replace those with a matched set that is 90-100lbs at 1.75in. A valve job will be needed. Make sure they back cut the stock valves to remove the heavy lip on them.

 

[87we410877]

Thanks alot!! Hey why replace with 90lb springs if 70 was stock? Just curious. And if the valves look good as well as the seats should i still get a valve job done?

 

[bsdlinux]

Thanks alot!! Hey why replace with 90lb springs if 70 was stock? Just curious. And if the valves look good as well as the seats should i still get a valve job done?

Look its your money, but it would be foolish at this point not get the heads done and ported. It the same work to put either the old ones or the re-worked ones on.

 

[bison]

Thanks alot!! Hey why replace with 90lb springs if 70 was stock? Just curious. And if the valves look good as well as the seats should i still get a valve job done?

The factory springs were barely adequate for the stock application when new and the springs will relax after a little running. Id rather have a set on there that wont allow valve float and rev to 5000 rpm with no problems. If you ordered springs from GM they would cost a lot more than the 90lb springs from a vendor like Kirban and they wont rev past 4800 too well like the stockers. I never did a dyno test before and after springs but there is a noticeable difference when changing even with the stock cam. No worry about lobe failure since you cam is already well broken in. Ive never seen a TR engine with a decent exhaust valve seat with over 30k miles on it. Id bet yours are really pitted up and leaking. The valves should look ok but the valve job and back cut will really make them nice. If your freshening go for the plate hone and file fit rings.

 

[87we410877]

Look its your money, but it would be foolish at this point not get the heads done and ported. It the same work to put either the old ones or the re-worked ones on.

Or i can take the champion aluminums off the other motor and not even worry about the porting. But, as i said, its going back to stock as possible. 210 at the wheels and a 14.2 in the 1/4 would be fine.

 

[87we410877]

The factory springs were barely adequate for the stock application when new and the springs will relax after a little running. Id rather have a set on there that wont allow valve float and rev to 5000 rpm with no problems. If you ordered springs from GM they would cost a lot more than the 90lb springs from a vendor like Kirban and they wont rev past 4800 too well like the stockers. I never did a dyno test before and after springs but there is a noticeable difference when changing even with the stock cam. No worry about lobe failure since you cam is already well broken in. Ive never seen a TR engine with a decent exhaust valve seat with over 30k miles on it. Id bet yours are really pitted up and leaking. The valves should look ok but the valve job and back cut will really make them nice. If your freshening go for the plate hone and file fit rings.

Thanks so much. I'll get the heads and valves checked out. The block was already honed and am in need of stock bore rings. Thanks for all the info, its been really helpfull!!

 

[bsdlinux]

But, as i said, its going back to stock as possible..

Use your stock head, vlave job and little porting..done!! Save the Champions for a real build up

 

[87we410877]

Use your stock head, vlave job and little porting..done!! Save the Champions for a real build up

Have you read my SIG? hahah. I need both ends of the spectrum and this is the slow end. Stock heads are in the shop now getting valves cut and seats cut possibly a mill. Thanks.

 

[bsdlinux]

Have you read my SIG? hahah. I need both ends of the spectrum and this is the slow end. Stock heads are in the shop now getting valves cut and seats cut possibly a mill. Thanks.

Yeah I saw that, I'm just a smartass. Never mind me

 

[87we410877]

what oil were using throughout the engine's life, rotella t? If it worked for you, I may have to give it a shot!

The oil used was Bull Dog or Bully Dog diesel oil for high compression diesel motors.