Racers Using Hydraulic Cams Chime in

[67Satty]

I'm thinking of doing a cam and head swap. Right now my car launches decent and seems to have good low-end power but runs out of steam at 5,000 rpm. Best time in the 1/8 so far is 7.86 which would be like running a 12.30 or so in the 1/4.

I called Jim at Racer Brown and had an eye-opening conversation with him. The gist was, yeah that's what I'd expect your car to do (running out of steam at 5,000 rpm) with low-compression, low duration, wide LSA, and stock 452 heads.

I'll be swapping the heads for Stealths or Edelbrock RPM-type heads (looking at the Sidewinders or ProMaxx heads too) so that will get my compression up to over 10:1 and my flow up at least 50-60 cfm.

He suggested and made a very good case for going with a cam that is .520 lift, 254 @ .050 duration and a tight 106 LSA, for sure no more than 108 LSA. My current hydraulic Engle cam is .534 duration, 238 @ .050 duration, and 110 LSA. He said the wide LSA was hurting my low end while the small duration was hurting the top end. He made a pretty good case for going against the trend of higher lift, lower duration hydraulic cams.

I'd like to hear from people who are racing with hydraulics and able to rev them to near 6,000 rpm. Is it possible or is the hydraulic lifter a limiting factor with lifter pump up? I could also go with a solid from him with the same specs but that would mean having to buy new pushrods. Thanks for any feedback!

 

[lewtot184]

ask jim about an st21.

 

[67Satty]

We talked about that one. First, he recommended ST-H-42, the hydraulic that is .520 lift, 254 @ .050 duration. When I said I was interested in a solid to eliminate the variable of hydraulic lifters pumping up at high RPM, he mentioned the ST-21 which has the same specs, only solid lifters.

I was just wondering if there was any disadvantage of going with the hydraulic lifter version in terms of wanting to spin it up to close to 6,000 rpm.

 

[1967coronet440]

We talked about that one. First, he recommended SS-H-42, the hydraulic that is .520 lift, 254 @ .050 duration. When I said I was interested in a solid to eliminate the variable of hydraulic lifters pumping up at high RPM, he mentioned the ST-21 which has the same specs, only solid lifters.

I was just wondering if there was any disadvantage of going with the hydraulic lifter version in terms of wanting to spin it up to close to 6,000 rpm.

I could be wrong but isn't that about where hydraulic cams tend to become a problem, 6000+ rpm?

 

[PurpleBeeper]

I could be wrong but isn't that about where hydraulic cams tend to become a problem, 6000+ rpm?

That's the word on the street. "Back in the day" Rhodes lifters were supposed to take you up to 6500 rpm if I recall correctly. So, I believe you can rev a hydraulic to 6-grand (I have), but 7-grand, no & 6500-"maybe".

 

[67Satty]

If I could rev it to 6,000 without problems, I think that would be plenty. Just wondering if there are any racers on here that could tell me their shift points using hydraulic cams.

 

[bobtile]

I had a hydraulic roller in my GTX.
.535/.550
.231/.239
110 lsa.
1.6 rockers.
Shifted at 5800 and through the stripe at 6000.
Car ran 11.20's

 

[Zeppelin264]

Running the Lunati 60304 cam. Car pulls hard to 6k which is my red line. This is a Nitrous cam too i guess.

So that's why I need nitrous now. Because my car has a nitrous cam. haha

 

[lewtot184]

a solid will make more power thru out the rpm range. the st21 is an over achiever. hydraulics have their place but i've never understood the love affair for them in a true performance engine.

 

[bobtile]

I built mine as a street car and then decided to race it later.
I just figured hydraulic would be easier on parts for street use.

 

[68Charger440HP]

I race a very mild Mopar Performance cam. It's the purple shaft 280 cam. My car likes 6000 rpm shifts and runs 11.6's @ 117 mph. I do have Trick Flow heads though which seemed to extent my power band several hundred RPM. Prior to the Trick Flows I was running stock iron heads and shifting at 5700 rpm. If the cam you currently run is in your sig., I would think it would like more RPM. You mentioned being low compression. What compression are you at?

 

[Dodge 330]

I had a hydraulic roller in my GTX.
.535/.550
.231/.239
110 lsa.
1.6 rockers.
Shifted at 5800 and through the stripe at 6000.
Car ran 11.20's

Pretty much exactly the same scenario and cam specs here. Howards hydraulic roller. They recommend limiting the lifter I bought to 6500. Rev limiter is set to 6400 on the MSD and it revs freely to that rpm.

 

[POMONAMISSEL]

i've run my 440 comp cams hyd cam pass 6500 , on a missed shift 8k , still together . corrillo rods 6pck , keep it that way . its been sitting for awhile , i keep my license that way , lol .

 

[67Satty]

I race a very mild Mopar Performance cam. It's the purple shaft 280 cam. My car likes 6000 rpm shifts and runs 11.6's @ 117 mph. I do have Trick Flow heads though which seemed to extent my power band several hundred RPM. Prior to the Trick Flows I was running stock iron heads and shifting at 5700 rpm. If the cam you currently run is in your sig., I would think it would like more RPM. You mentioned being low compression. What compression are you at?

I'm at about 9.5:1 but I also have to contend with racing at a track that averages 3,000' density altitude. So a little more cylinder pressure from running more static compression and a tighter LSA could help me.

 

[LemonWedge]

Certainly it's possible to rev a juice cam to 6k and above. But A solid of the same profile will always Make more power and offer better valvetrain control. After running a solid for 7 years now, I'll never go back to a juice cam. Maintenance is simple and I dig the sound. Mine is a very street friendly Engle custom grind. Similar to their K-8, but with a little less duration and slightly wider LSA.

 

[cdr]

I run a solid FT cam in my street car, to many problems with mopars & hydro lifters.

 

[POMONAMISSEL]

been seeing that hyd lifter issues in resent builds .

 

[lewtot184]

i believe the major problem with the hydraulic tappet is that folks want mechanical tappet performance from something that was never designed to be competitive with a solid tappet. cam designers/grinders keep pushing the envelope to satisfy the consumers desires. this all stems from the fact the hydraulic lovers don't understand the limits of the hydraulic tappets and don't want to understand the benefits of the mechanical tappets and lobe profiles. it's a recipe for problems.

i remember back in the day a friend, die hard hemi guy, used to say when the 1970 street hemi came out with hydraulic tappets that "it was a machine gun with no bullets".

 

[Tex013]

I ran the mopar 509 hydraulic fir several years . I think 11.12 or 11.18 was best et . Shifted at 6000 trapped 6200ish . This was in a 440ci .
Plus i used this as a daily driver

Tex

 

[383man]

The only hyd cam I raced with was the MP .484 cam in my old 383 Dart. I pushed it to 5600 and it pulled up to that. It ran a best of 12.31 @ 110 in my 3600 lb Dart with me in it. Ron