[d.b. cooper]

Is this a monte carlo?

 

[d.b. cooper]

Here's the flat tappet cam GM used in smog era L69 "H.O." 305 Camaros: 202/206, .403/.415, 114.5

The heads were also somewhat performance oriented, and compression ratio may have been more.

Good info here: L69 cam specs ? - Third Generation F-Body Message Boards

Only 202/206 @.050 ?
That seems pretty tame even for a 305.....?

 

[d.b. cooper]

Anyways, another way to get choppy/lopey is to switch to manual choke; When you want chop, close the choke up. Back to normal, open it up......

Not saying anyone SHOULD do this, i'm just saying this is a way to get choppy / lopey without messing with the cam.....

 

[d.b. cooper]

Turn the idle mixture screws in a bit to lean it out. Make it sound like It's got a hot cam. And when you get tired of it or the exhaust burns your eyes turn them back out. Easy and inexpensie.

Yeah, this too.

i /we suggest this if you want to "make noise" at the traffic light without having make any major modifications to the engine which could adversely affect performance/driveability.

(i've just realized how immature this is.......)

 

[d.b. cooper]

Using a flat tappet cam and lifters today is a crap shoot at best. With All the stories about junk lifters and cams going flat. Sounds like your trying to go thru a lot of work on a possible engine that needs more than just a cam swap. You may be dis appointed in the out come. Just saying.

^^^^^^^^THIS^^^^^^^^^ is how i'm feeling as well lately.
i think the trend is going towards roller cams and thus the cam companies aren't putting much effort into flat lifter cams?

How much would it cost, and what is involved, to switch to a roller cam in this application?

 

[d.b. cooper]

i've got my own car problems crop up, which i'll likely describe in another thread. So i don't have time to really get whole-hog into your own interesting situation.

Until then, can you zoom out with a picture of the engine? i get a sense that the engine and car is cobbled together. i am not putting you down, just saying what my gut feeling is.

If we can get a better assessment of the engine and car, then we can give better recommendations.

Thanks.

 

[d.b. cooper]

Doesn't make much sense in an old worn out 305. https://www.jegs.com/i/COMP-Cams/249/K12-407-8/10002/-1?year=1984&make=CHEVROLET&model=MONTE+CARLO

Need to have the different springs with a roller cam to handle the additional weight of the heavy roller lifter.

I have a theory that a lot of the flat tappet cam failures stem from using flat tappet cams with roller-cam springs. A lot of the modern aluminum heads come with roller cam springs and require an alternate spring option to get the correct ones for a flat tappet cam. Don't think a lot of people worry about this, about breaking things in correctly, or about using high-ZDDP oil.

Yeah, my gut feeling is if you've got stock-ish valve springs, you'll be ok with a flat lifter cam.

My last two engines were flat lifter ---a crate 350 and a 305 out of a 78 malibu. Never any cam problems. i did use Redline 10w-30 just to be safe because it has the certified ZDDP amount.

My last car with flat lifters is a cavalier with the 2.0 4cyl. 340,000 miles, original cam still good. i did start using royal purple around 15 yrs ago. But again, my hunch is the key is the valve spring pressures: Stock is ok. Anything beyond that you have to be careful.

Everything else i have now is roller lifter. i doubt i will ever build or buy something with flat lifters from now on.