A different "what cam" thread

[dart_68]

There are often posts about what camshaft to get. It will entirely depend on the desire as to what you want to get from the engine with the ensuing discussion of the combination.
This post is not about X lift vs Y duration vs Z lobe separation. This is about what type of camshaft you might want to consider, or in other words what type lifter. Here is my humble take on what I’ve learned.

Hydraulic flat tappet -

Advantages -

1) Lower overall cost.
2) Possible to use some stock components (rocker arms, push rods, springs but depends on cam).
3) Less maintenance.

Disadvantages -

1) Engine must have working tune on initial startup to break in the cam. If the tune is too far off and engine won’t start or run to breaking RPM you could wipe the cam.
2) Lifter quality has been very iffy as of late.

Solid flat tappet -

Advantages -

1) Lower overall cost.
2) Possible to use a more radical cam.

Disadvantages -

1) Engine must have working tune on initial startup to break in the cam. If the tune is too far off and engine won’t start or run to breaking RPM you could wipe the cam.
2) Lifter quality has been very iffy as of late.
3) Requires adjustable rocker arms.
4) May need different push rods, possibly custom made.
5) May need new valve springs to match camshaft.
6) Valve Clearance must be set and maintained regularly.

Hydraulic roller tappet -

Advantages -

1) No real break in procedure.
2) Possible to use a more radical cam.

Disadvantages -

1) More expensive – will most likely to need to buy complete valve train...cam and lifters are more expensive than either flat tappet type.
3) May require adjustable rocker arms.
4) May need different push rods, possibly custom made.
5) Will need new valve springs to match camshaft.
6) Valve Clearance may have to be set and maintained regularly if using adjustable rocker arms.
7) Block may require special machining to accommodate roller lifter.
8) Will most likely require the use of a bronze intermediate shaft gear or a specially treated iron gear. There are some hydraulic roller cams that have an iron gear pressed on instead of billet. If so, stock type iron gear on intermediate shaft will work.

Solid roller tappet -

Advantages -

1) No real break in procedure.
2) Possible to use a much more radical cam.

Disadvantages -

1) More expensive – will most likely to need to buy complete valve train...cam and lifters are more expensive than either flat tappet type.
3) Will require adjustable rocker arms.
4) May need different push rods, possibly custom made.
5) Will need new valve springs to match camshaft.
6) Valve Clearance will have to be set and maintained regularly.
7) Will require the use of a bronze gear on intermediate shaft.
8) Block may require special machining to accommodate roller lifter.

All of the above will depend on what you are starting with. My engine came from the factory with a hydraulic roller cam and I chose to go with the same when upgrading. However, if I had to do over again I would have gone with a solid roller cam. Too many potential problems with the current stock of flat tappets. I had to buy a complete valve train anyway...should just have gone solid.

What say you?

 

[RustyRatRod]

With the good quality parts available now, you can scratch regular and frequent valve adjustments off the list.

 

[AJ/FormS]

"what say you?"
IMO, I say;
1) On the street, with modest cams, FTcams and the .904 lifters can offer more lift, a lil sooner off the base circle, and thus, size for size, a bit more performance overall, than rollers.. I mean, for me, Ima thinking, for a streeter, a FTH is the bees knees.
2) I like Hydros cuz I can set mine with only a little preload, lots of spring pressure, and run them many hundreds of rpm past the PowerPeak, without them pumping up; and, they don't seem to mind running a few thousands loose, which would likely kill a roller. and
3) they're always quiet. and
4) For me, setting the break-in tune is a none-issue; and
I've never lost a cam at start up. ...........
which ain't saying much, cuz that's like a half a dozen, lol. and
5) Setting the valves a few times during the early life of the hydro, to me, is not a big deal.
_______________________________________________________________________
BTW,
And the following,
is to anybody reading this in the future, and not to anyone in specific;
My cam is a long discontinued Hughes HE3038AL; 230/237/110 and .549/.571 [email protected]. which has stood the test of time, having been installed in 2004, and, if I had to guess, it would be pushing 100,000 miles.
I'm guessing but, IMO, this size of cam is pushing the upper limit for a manual trans car with 3.55s. Yur gonna need a starter gear of 11/1 or more to parade with it, which points to a 5-speed..
The start up tune is easy; yur only on the transfers. Just rev it up to say 2200, pull in as much timing as it likes (whatever it is, is unimportant), then lower the rpm to 2500, twiddle the mixture screws up to half a turn from their midpoint,
and so; in about a minute, yur all set.
Then sit back for twenty minutes, and watch for leaks and overheating, which, if you've done your prep work, you won't have any of.
If that scares a you
well then yeah, I suppose you better
get a roller, an automatic, a high stall, and some gears .
Or just start with a bigger engine in the first place....... to enable the use of a smaller cam.
Which I think, in the big picture, is the better idea..... especially as the price of gas rises ever higher.
These are my opinions