Has anybody gotten all you can get out of a stock cam?

[HowlerMonkey]

In that I mean......."has anybody done everything possible to maximize horsepower using the stock cam".

 

I know most people go to a bumpier cam when they want more power but I'll bet you can get a lot more power from a stock cam than most would think by optimizing the shape of the valves and ports to maximize flow at stock valve lift.

 

A lot of the newer cars sure are making big power with relatively low valve lift.

 

Is there a "record" for power on the stock cam?

Edited September 5, 2013 by HowlerMonkey

[JMortensen]

Why waste time and effort to see what you can do with a stock cam? Those newer cars have 4 valves per cylinder. The two valve engines use HUGE lift numbers compared to the L engine. LS1 has about .500". That's a pretty big cam on an L.

 

There was a guy some years back who made 400whp on a stock head turbo L28 who was claiming the most hp on unported head with stock cam. Great, but he could have been doing a lot better, if doing better was the goal.

[madkaw]

We might be surprised if someone took a late zx and MS'd it and spent some serious dyno time. I think that would give the biggest gains compared to grinding any part of the head.

[HowlerMonkey]

I guess I posted this because of the huge amount of camshaft fail stories I keep seeing.

 

I think you can get more power than most people think and have an engine that will easily pass emissions.

Edited September 6, 2013 by HowlerMonkey

[beermanpete]

Talk to people who race, or have raced, in classes requiring stock cams. They are likley the people who have work the hardest to get power from a relatively stock engine.

[johnc]

Sunbelt got 208hp at the crank on an ITS spec L24. That's a stock E88 head (no porting, stock size valves, stock can, stock springs), stock bottom end, SU carbs, headers, ignition. The customer paid close to $10k forvthatcengine and all the R&D and parts swap blue printing. He went on to with ITS at the ARRC two yeasts in a row.

 

Without the rules limitations you can get 250 or more horsepower with the same budget. That's why sane people don't artificially limit their builds with some odd parameter.

[Kirkster]

I am one of those not so sane people that will be trying to eek everything I can out of a stock head with an .040 bored block. Those silly SCCA rules. I am going to try and campaign a 73 240z in BSP over the next few years...

 

I am stuck with the stock cams and dished pistons... Build will be commencing in mid September....

 

Still searching for someone to do the bottom end work on a 77 280z motor that will be going in my car.

 

Still trying to figure out the intakes and throttle... Will be going fuel injected with a complete Megasquirt managing the engine and E85 for fuel...

Edited September 6, 2013 by Kirkster

[Tony D]

Steve "Stealth" Webb took a junkyard hydraulic cammed L28ET with 160,000+ miles on it, bolted his EMS/Turbo and ran the dyno to 460...

It's the "Maximum Boost" mentality...

You don't "need" to do anything other than fuelling and boost and you can make big HP.

 

But JeffP made almost 40HP more with half the boost by changing to a ported cylinder head and cam.

 

Why did Steve do it? Because his "built" engine blew during tuning and he wanted to drive the car to Albuquerque ZCON.

Why did JeffP do it? Because his "built" engine blew a second time and he didn't feel like another $3,000 refresh just quite yet.

 

See a common thread here?

[johnc]

Racing rules make otherwise sane people do insane things. Been there, done that.

[HowlerMonkey]

I'd just like to see what can be done with investing in labor (porting, combustion chamber shaping, and valve reshaping) as opposed to investing money (parts such as camshafts).

 

I don't think an Improved Touring engine would be a good reference to my question since they are limited by SCCA in far more areas than simply the camshaft and I've built ITS 240z engines off and on since about 1986.

 

It would be cool to see how far a stock cam profile that will pass emissions and last 300,000 miles can be taken if you optimize everything except for the cam.

 

This means my question covers any permutation of stock cams, heads, and blocks but with unlimited amount of optimizing everything else.

 

I understand the changes to motor oil have not favored engines that have high psi loads between lobe and cam follower but I'm not seeing undue wear to factory parts in super high mileage engines even with the newer oil formulations in comparison to the many threads showing aftermarket cam or follower failure.

Edited September 6, 2013 by HowlerMonkey

[JMortensen]

While you're at it, why not fuse your ankle and then see how fast you can run a 440?  

[HowlerMonkey]

Funny you mention fused ankle.

 

I will gladly race you with my fused ankle as long as it's on a sandy beach.....which is where I do my interval sprint training.

[JMortensen]

Ha! You'd probably win too.

[Xnke]

Which stock cam?

 

Best I was able to strangle out of an L28ET with the "K" cam was 220HP, at 14lbs on a T04E-50 turbo. It's one of the smallest, if not the smallest, cams offered factory installed in an L-6.

 

0.390" lift, 219* duration, duration @ 0.050" is only 188*...

[Tony D]

That's why I mentioned "Hydraulic"! That's supposed to be "The Bad One"!

[Xnke]

The hydro cam is 0.390" lift, but has more duration...240* seat to seat. Lobe separation angle are 110* on the turbo cams, both the solid lifter and hydrualic. Different opening and closing ramps, but still not a "Big Cam".

 

Bigger than the Maxima L24e "K" grind...0.390" lift, 219* duration, 106 lobe separation.

 

My Isky regrind is a 0.480" lift, 280* duration, on a 113 lobe separation.

 

"A" grind is 0.420" lift, 248* duration, on a 108* lobe separation.

 

"C" grind is 0.400" lift, 256* duration, on a 108* lobe separation.

 

If you have the spec on the L20A cam grinds, Tony, that'd be great, those are the ones I am missing from my list!

[z-ya]

Sunbelt got 208hp at the crank on an ITS spec L24. That's a stock E88 head (no porting, stock size valves, stock can, stock springs), stock bottom end, SU carbs, headers, ignition. The customer paid close to $10k forvthatcengine and all the R&D and parts swap blue printing. He went on to with ITS at the ARRC two yeasts in a row.

 

Without the rules limitations you can get 250 or more horsepower with the same budget. That's why sane people don't artificially limit their builds with some odd parameter.

 

John,

 

So you mean all they did was balance an blueprint it? So if everything is stock, then how did they get over 50HP more than stock?

 

Pete

[HowlerMonkey]

A "blueprinted" IT motor is far more than what the term "blueprinted" means in this case but also far less than what you can put together for a street motor while still using the stock camshaft.

 

In Improved Touring you can go .025 beyond the service limit of cylinder head thickness as long as you don't increase compression ratio more than half a point.

 

You can port match but not further than 1 inch from where manifold meets the head.

 

You can't assemble an engine from multiple years meaning the engine specs. are for the entire package for the year you are representing as your car.

 

.040 is the maximum overbore from stock.

 

You can't lighten rotating parts beyond what you need to remove to balance the assembly.

 

For pistons, they specify that dome/dish/valve relief configuration, ring groove width and spacing, and pin height relationship be the same as stock and weigh the same as factory pistons if you had to go with non-factory pistons.

 

Valve guides might be open.

 

Compression 70 to 73 are allowed 9.0 while 1974 260z is allowed 8.9 and 1975 on engines are allowed 8.3

 

I don't remember valve job angles and camshaft timing or specs but it is pretty well policed........if you finish in the top 3.

 

Within the rules, there is a lot you can do to optimize an engine but on the street, the limitations above don't apply.

 

I'm sure a F54 block with the MN47 head using flattops could make some big HP but you have to either run better fuel than california 91 octane, reduce timing below optimal, or find a way to reduce overall mechanical compression ratio.

[roger280zx]

IIRC Garret did 460 atw with stock head/A grind cam.  Bored to 89mm with custom intake mani, 70mm tb, big ole mismatched turbo and lots of boost.  I would say that is probably as close to a record you're going to get.  After all we have Datsun's, not evo's.

[roger280zx]

We might be surprised if someone took a late zx and MS'd it and spent some serious dyno time. I think that would give the biggest gains compared to grinding any part of the head.

Serious dyno time.. what like $2500 to extract what?  30-35hp more.  I'd rather put 2500 in head and cam, then with typical $350-400 dyno time make 200hp more.  But that is if it were my money.