Pros and Cons for using a Hydrlic cam Options

[jims914]

Anyone running a hydraulic cam ?
What cam used, lifters, pushrods, cam gear ?
Looking at a 74 2.0 fuel injected engine to use it in ?

[mepstein]

Don’t do it.

[Chris H.]

(IMG:style_emoticons/default/agree.gif) For the convenience of not having to adjust valves (pro), you will lose a LOT of performance (huge con).

[rjames]

(IMG:style_emoticons/default/agree.gif) For the convenience of not having to adjust valves (pro), you will lose a LOT of performance (huge con).

What does “a LOT” mean?

[Superhawk996]

(IMG:style_emoticons/default/agree.gif) For the convenience of not having to adjust valves (pro), you will lose a LOT of performance (huge con).

What does “a LOT” mean?

5-7% less HP on dyno isn’t uncommon for V8 SBC.

Not sure I’ve ever seen a back to back dyno comparison on a VW T4 motor of hydraulic vs solid lifters. Probably because you have to completely tear down the T4 to change the cam and lifters. Much easier swap on a SBC that can be done without even removing the engine from the dyno

Well known limitation of hydraulic lifters is that they begin to lose control of valve train as RPM’s go up. T4 not exactly a high revving engine but why give up anything HP wise just because it takes some effort to adjust the valves? Another disadvantage with hydraulics is that they love clean oil. Tight operating clearances of hydraulics are prone to failure if dirty and long oil change intervals aren’t addressed. Think the T4 vavle train makes a lot of noise? Trust me it’s nothing compared to a failed lifter that won’t pump up.

Valve adjustment on a T4 isn’t hard. If anyone thinks it is, they have never done adjustment on shim and bucket lifters, or God forbid, a Ducati desmo engine!

[Root_Werks]

Wow you guys, hydro lifters aren't bad at all.

@Kelty360 - Maybe Marc can chime in.

Running Hydros on my Bug and 914-6 and LOVE them. Easier to adjust (and only once I might add!) than solid lifters, nice and quiet.

I guess if you're building a race car or engine you want to push RPM's a lot, solids are better. For Driver cars, love, love, love hydro lifters.

[rjames]

I asked what the definition of 'a lot' meant, because I have them in my car (rebuild by PO) and the only issue I have with them is how noisy they are waiting to pump up with oil if the car sits for an extended period of time. I've never seen anything showing how much HP is left on the table compared to solid lifters. My car still pulls to 5k rpm. My guess is that any loss in performance would be pretty minimal on an otherwise stock engine and was probably more than made up for on my car when I backdated the exhaust.

If I were doing a rebuild I'd likely ditch them, but mostly because I've been swayed by all of the naysayers over the years. The older I get, the happier I am not to have to crawl under the car to do regular valve adjustments.

[KELTY360]

I can only comment from a seat of the pants perspective. I've had my '74 2.0 since 2006. The PO rebuilt the engine with euro pistons and hydraulic cam and lifters. The engine revs freely through the power band and I've matched acceleration with other 914 2.0's.

I've had occasions where the car sat for a month or two and the lifters had to pump up. The clatter can last as long as 10 minutes and I usually just let it idle in the driveway. They have always pumped up fully. I'm running a Triad dual exhaust and like the sound of the engine.

In all, I didn't choose the hydros but I've been pleased with the performance and convenience over the years.

[jims914]

Thanks for all the input.

[r_towle]

Convenience is key

[richb45]

I can only comment from a seat of the pants perspective. I've had my '74 2.0 since 2006. The PO rebuilt the engine with euro pistons and hydraulic cam and lifters. The engine revs freely through the power band and I've matched acceleration with other 914 2.0's.

I've had occasions where the car sat for a month or two and the lifters had to pump up. The clatter can last as long as 10 minutes and I usually just let it idle in the driveway. They have always pumped up fully. I'm running a Triad dual exhaust and like the sound of the engine.

In all, I didn't choose the hydros but I've been pleased with the performance and convenience over the years.

I have pretty much the same experience. I've owned my 72 with a 75 2.0 since 2013. The PO rebuild included the hydraulic lifters. Not sure about the cam though. I assume it was also changed. The Engine was built by Boston Bob a few years earlier. The hydro's ran fairly quiet unless the car sat for a month like your experience. Recently though they've become more noticeably loud. I tried Liquid Moli Hydraulic tappet additive which seemed to work for a short time, but the noise recently started to come back. The additive thins out the oil so it can flow easily through the lifters but I'm thinking that they may be beginning to fail. I've been told that switching back to solid ones is the way to go. But if I have to change a cam? No way. I had good performance and reliability up till now, why not just change to a new set of hydraulic lifters?

[Root_Werks]

I can only comment from a seat of the pants perspective. I've had my '74 2.0 since 2006. The PO rebuilt the engine with euro pistons and hydraulic cam and lifters. The engine revs freely through the power band and I've matched acceleration with other 914 2.0's.

I've had occasions where the car sat for a month or two and the lifters had to pump up. The clatter can last as long as 10 minutes and I usually just let it idle in the driveway. They have always pumped up fully. I'm running a Triad dual exhaust and like the sound of the engine.

In all, I didn't choose the hydros but I've been pleased with the performance and convenience over the years.

I have pretty much the same experience. I've owned my 72 with a 75 2.0 since 2013. The PO rebuild included the hydraulic lifters. Not sure about the cam though. I assume it was also changed. The Engine was built by Boston Bob a few years earlier. The hydro's ran fairly quiet unless the car sat for a month like your experience. Recently though they've become more noticeably loud. I tried Liquid Moli Hydraulic tappet additive which seemed to work for a short time, but the noise recently started to come back. The additive thins out the oil so it can flow easily through the lifters but I'm thinking that they may be beginning to fail. I've been told that switching back to solid ones is the way to go. But if I have to change a cam? No way. I had good performance and reliability up till now, why not just change to a new set of hydraulic lifters?

Search The Samba for sticky lifters, the Type 2 folks have lots of great tips. You're just getting varnish or residue built up on the lifters. What's working best for me is not letting the cars sit for more than a month (usually try to drive weekly) and switched to 5-40 Castrol Euro spec oil. Seems to work very well.

[brant]

and I do not really know if you can just change to new hydraulic lifters or not.

with solid lifters the cam and lifter hardness has to be matched, or bought at the same time from the same manufacturer... and then the lifter wears "in" to the cam and matches for life.

not really sure if that is true of hydraulics or not... but if it is... you may not be able to "just put in new lifters" without also putting in a new cam anyways...

cleaning your sticky lifters would absolutely be the way to go if you don't want to change cam.. easier... cheaper... more likely to be successful.

[JamesM]

Anyone running a hydraulic cam ?
What cam used, lifters, pushrods, cam gear ?
Looking at a 74 2.0 fuel injected engine to use it in ?

When i had a 2.0 built for me ~20 years ago when i used my 914 as my only daily driver i thought it would be a good idea not to adjust valves.

At the time not having to adjust valves was nice.

BUT

I dont think i would use one again, especially now.

When i started to autocross my 914 the performance issue became apparent. It wasn't so much the loss of power as the loss of the ability to reach high revs. Below 4500rom was fine but really falls on its face after that.

also

I dont get to drive my 914s enough anymore so valve adjustments are very infrequent.

Adjusting valves isnt that hard.

lifters going flat/sticking isnt the end of the world but does become a regular annoyance if the car sits for any length of time.

Near the end I was trying to blow the motor up just so i could have an excuse upgrade, I never managed to, still ran great when i pulled it. REALLY happy with the built 2056 that replaced it though.

[brant]

all the fun of these power plants is at the top end.
not revving up past 4500 really would take the fun out of it.
makes it into a non sports car... in a way...

I have 9K valve train in my race car... I don't redline past 8K... but all of the "fun" in that motor is at the top end....

[technicalninja]

Lifters are worn into the cam lobes on EVERYTHING!

In 40 years of active wrenching employment, I've never seen an unmatched set function for more than 1 month.
Even changing position on the original cam leads to failure.

The lifter is matched to a single cam lobe.

I am stupid careful to keep them in proper order if I remove them from the engine.

A mix up is fatal.

The ONLY exception to this rule is shims in a shim over bucket application. Those seem to work fine.

There may be exceptions to this but I've never seen swapping stuff around work for very long...

[mb911]

Wow you guys, hydro lifters aren't bad at all.

@Kelty360 - Maybe Marc can chime in.

Running Hydros on my Bug and 914-6 and LOVE them. Easier to adjust (and only once I might add!) than solid lifters, nice and quiet.

I guess if you're building a race car or engine you want to push RPM's a lot, solids are better. For Driver cars, love, love, love hydro lifters.

Can I ask how your running hydraulic lifters on a 914-6? 993 valve train?

[Root_Werks]

Wow you guys, hydro lifters aren't bad at all.

@Kelty360 - Maybe Marc can chime in.

Running Hydros on my Bug and 914-6 and LOVE them. Easier to adjust (and only once I might add!) than solid lifters, nice and quiet.

I guess if you're building a race car or engine you want to push RPM's a lot, solids are better. For Driver cars, love, love, love hydro lifters.

Can I ask how your running hydraulic lifters on a 914-6? 993 valve train?

Ben,

Don't remember anymore, you'd have to search through my 914-6 "refresh" thread. I didn't build the engine. But sort of recall yes, 993 stuff:

http://www.914world.com/bbs2/index.php?showtopic=344276

I don't spin past 6500RPM (limit control).

-Dan

[mb911]

Wow you guys, hydro lifters aren't bad at all.

@Kelty360 - Maybe Marc can chime in.

Running Hydros on my Bug and 914-6 and LOVE them. Easier to adjust (and only once I might add!) than solid lifters, nice and quiet.

I guess if you're building a race car or engine you want to push RPM's a lot, solids are better. For Driver cars, love, love, love hydro lifters.

Can I ask how your running hydraulic lifters on a 914-6? 993 valve train?

Ben,

Don't remember anymore, you'd have to search through my 914-6 "refresh" thread. I didn't build the engine. But sort of recall yes, 993 stuff:

http://www.914world.com/bbs2/index.php?showtopic=344276

I don't spin past 6500RPM (limit control).

-Dan

Yup I see that now. Very cool