Dark Energy

I called in a cam that I had in mind and was sent the spec's for purchase. I understand I could call or text back to have him do it but Time is money and I'm about a month away from purchase.
So Here's what I got when I called it in BUT......decided I didn't want to rev that high(stall would be to crazy also unwanted RPM) and was thinking of taking the LSA down to reel in the RPM.

RPM max 8800 with 4 inch arm or Crank

282/292 @.050"
.436"/.436" Lobe Lift
.763"/.763" Net Valve Lift (after Lash)
116 LSA

Would a 108 lsa bring me to around 7900 to 8k even. I don't want to come back down on Duration it get's me near where I would like, I just want it to make peak making HP at around 8k.

Old Geezer

iTrader: (3)

Advanced engineering???

KCS

iTrader: (20)

I don't know about a 108 LSA; that's pretty tight for that much duration. Closing the intake valve earlier is heading in the right direction to get it to peak earlier, but too much overlap could hurt. Maybe split the difference? Scale back the intake duration a little bit and settle on an LSA between 108 and 116.

Dark Energy

Advanced engineering??? That's why I posted over here I didn't need the BS. Trying to keep things simple.

KCS I'm with you but Mike spec'ed it for around 8800 to 9k. I based it off of old Dwill's cam just more Duration as I'm thinking with the Holley High Ram with x2 TB's would really be a eye opener. Sounded good to rev that far but not for me in the real world.
Guy's over @ pipe max said it would peak at what Mike said with a Hp/Tq number I was happy with on there simulator. Got to thinking if I could just keep the same spec's and just have it die at around 8100 thinking it max around 7800 to 8000 and I'd be happy. The base line for the peak Tq would I think come in around 6100 to 6300 would like it to be around 56 to 5900. I just want it to peak @ 8k with the same spec's.

Darth_V8r

iTrader: (4)

KCS probably right. Try something like 112 LSA and also advance the cam four degrees further. Intake valve close is usually the biggest contribution to what rpm you peak at

Dark Energy

112 + 4 built in looked good on my own Sim. I'll ask Mike about it before purchase. I like using different guy's. Mr Smallwood did my last custom cam. Thanks!

pantera_efi

iTrader: (1)

Hi Energy, the Piston Speed@9000 RPM is 6000 ft/minute.
That's about the limit for engine life.

What I offer (no cost) is an EAP engine Model report.
I would need to know engine specification including port size/flow ?

This could be a great topic for the Advanced Section, engine "models".

Lance

Dark Energy

Just a simple little 408 with all the Good stuff: Morel bushed lifters, Total Seal Gap-less rings, GZ vacuum pump,3 Quart Accusump, etc.... The Engine was and is set up to Run Either Pump or 108 Race unleaded. As I have to different sets of heads one being FRH stage1 heads and a solid and the other being my Very own set of 1 off Custom Ls7 small bore heads done by D Morgan @ Reher.

The engine looks like this:
4.030 x 4.0 Bore x Stroke
Deck @ Zero with 54cc Ls7 heads= *14.2 Compression and *12.1 with 66'cc Ls3 heads
Induction will use a Holley Ram with Dual Accufab 4500 T/b's. Have one 4500 T/B now with Super Vic for the other combo.

Around 253 cc intake runner. Heads are getting CC'ed for volume. Way smaller than Stage1 267cc Ls3 heads. The bottom of the Runner to the deck is 1'1/4 for Ls3 & 1' 3/4 for the Ls7 . CSA for my Ls7 heads is: 2' 3/8 x 1' 3/8 Ls3 FRH stg1 heads has a CSA of : 2' 5/8 x 1' 3/8. They could be opened up more for more CFM but this is what Darin thought was Best.

2.200 Titanium stock LS7 intake
1.550 Ferrea 24° exhaust
Flowed on 4.060 bore 28” TP
CFM
Lift No. 1 No. 2
-------- ------- -------
0.2000 111.2 165.2
0.3000 167.2 238.7
0.4000 191.3 300.6
0.5000 213.8 336.2
0.6000 219.9 360.1
0.7000 222.8 379.7
0.8000 225.0 370.0
Darin Morgan
Induction Research and Development
EFI Calibration


This is just a engine I've always had in my head just buy parts and keep pushing. I'm on Ls7 heads now and there's not too much left on the Table as far as the engine goes. Have a little with the truck itself. LOL!!!!! Could have had the truck done with 3k in these heads without parts. I do love cylinder heads so the truck can Wait it's turn,as it Doesn't need much besides wiring.

Martin Smallwood

iTrader: (2)

You need to be looking at events, not LSA and duration.

What head and intake? Compression? NVM saw the last post. I don't think 108 is going to work at 14.1:1. I would be using at least C12 or C14.

For a 7500RPM peak and 8000RPM shift here is what I would do with 14:1:

272/288 .440/.430 113+4

This would want IMO around a 6000-6200RPM stall for optimum performance.

Are you wanting it to peak at 8k or shift at 8k? Your wording on your post confused me a little as to what you desire.

Dark Energy

Damn Ford wins Daytona.


I just want the peak Hp to be made at 8k to 8200 not 8800 to 9k with the same duration and lobe.

Martin Smallwood

iTrader: (2)

Again, you need to be looking more at the events themselves instead of duration. IMO you can't say I want peak HP to be made at 8000-8200 instead of 8800-9000rpm using the same intake duration and lobe as you would for the 9000rpm combo. It just doesn't work that way in my mind and from my experiences.

If you want peak HP at 8000, to fully utilize that HP being made at 8000rpm you're going to have to turn it past 8000. A good engine that makes peak at 8000 will most likely want to be shifted around 8600-8800RPM. I say a "good engine" because some don't carry power well past peak due to intake port turbulence, oiling, intake manifold restrictions or camshaft restrictions.

If you want 8000RPM to be your max engine speed then you need to bring the power peak down so that you can fully utilize the engine's entire power band.

If you wanted peak HP at 8000RPM, you would want something more like this:

276/292 .455/.445 113+4

Dark Energy

You Know that I no that your correct with what your saying. Dwill had pretty much the same cam 278/290 *112 except with .818 lift or BES Nova old 416 and both were within the same Camming range low 270 to mid to upper 270's. And I know what they made and did. Thinking that if anything I can tighten the Lsa from 116 to 112 + 4 & I'll have to deal with it. From what I've read if you have a cam like the one I listed or any other cam. Having a higher 116-118 Lsa makes a Flat long Continuous hp/tq engine that peaks late. Bringing it down to say 112+4 would make peak Hp/Tq earlier. I Maybe asking for to much in the pulling it back with the Lsa.

I like the cam that's for sure.

Martin Smallwood

iTrader: (2)

Again, you're thinking in LSA and duration.

If you have two camshafts that are the same duration (say for instance 280/290@.050) one has a 112+4 and one has a 116+4.

280/290@.050
112+4
Events:
81 BBDC
29 ATDC
32 BTDC
68 ABDC

280/290@.050
116+4
Events:
85 BBDC
25 ATDC
28 BTDC
72 ABDC

The cam with the 112+4 due to it's earlier IVC and later EVO will peak earlier because of this. It having more overlap, and the earlier IVC and EVO would probably boost torque output some (5-15 ft. lbs.) from 6000-7000RPM due to increased scavenging while the engine is in tune, but sacrifice it from 7000-8000RPM due to the earlier IVC and later EVO.

The cam with the 116+4 due to it's later IVC and earlier EVO will peak later because of this and sacrifice some torque output from 6000-7000. Having less overlap will decrease torque output from 6000-7000rpm along with the later IVC and earlier EVO, but increase torque production from 7000-8000rpm.

It's NOT the LSA that changes this, it's the events themselves.

Now, I still wouldn't pick either of these cams for your application though. The main thing that needs to be determined is the highest RPM you want to spin the engine. Then you can choose better where peak HP needs to be made.

pdxmotorhead

Just a random thought, if I wanted to turn that many RPM's it would get a dry sump.. At least on the sprint cars I've worked on, 7500 is kinda the ceiling for a wet sump motor, of course we are running them a lot longer on a oval than on a drag strip,,, but for longevity the wet sump sprints last about 1/2 as long before needing rings.. The methanol fuel saturates the engine sump MUCH faster than than the dry sump so we don't thin the oil out through the evening on a dry sump engine.. Plus then we have 12 quarts of oil to carry the heat out.. We only use -12 hose for the radiator(No thermostat).

Darth_V8r

iTrader: (4)

Good to see you posting again Martin!!

Martin Smallwood

iTrader: (2)

Thanks Darth, I try to swing through when I can.

Dark Energy

Pdxmotorhead: I know and understand that my engine can't live there without going drysump. Eric of HKE broke me down on simple short burst with enough oil in the event of Low oil pressure.*Accusump.


Mars I just want as close to 870-900 as possible. Something 1 off again I know if I had a bigger bore engine this would be without question easy. This set up is Only for testing and bragging rights. And the occasional street race when I do get a stall (no track as I will never cage my truck that makes you a racer and **** Tends to break at the track). The cam listed put's me in the ball game. I still have the 260 duration cam which would work with these heads just as good as the other set. I can live with the cam as is but would like for it to peak a little earlier. 112+4 sounds good to me. As of now for the Ls3 combo: 4.56 rear end with a 4l80e+ 4k single disc stall. It's a S10 with alot of things removed. Should weigh in around 2700-2800. Had to take it down to the frame and replace the cab and most of the front/core support. Rust!

Dark Energy

I just may have to deal with it and except it. It's not a everyday setup. Neither should the other 1 LOL!

Martin Smallwood

iTrader: (2)

To get as close to 900 as possible you need one thing, RPM. To make 900 you're going to need power to peak in the 8600-8800 range with the cubic inches you have.

I don't think you're going to be able to make 900 only turning it 8000rpm with a 408" engine. If it were a 440"+ engine you could possibly make close to 900 only turning 8000rpm at 14:1 compression. Hell, BES made 1140HP with a 457" engine at 8400RPM and turns it right at 9000RPM. They had more compression and a better head though.

If you want to make big power at a lower engine speed you need more cubes.

Dark Energy

I've got the *RPM quoted @ that. # 870 fwhp. This is just for me and what I consider a Street truck. Not looking for a certain # but ball park and 850 is not it. I'm not willing too Look or do what's been Done. The cam listed is good for 850-870 on a Tight dyno. I'm not tripping this IS just what I do. I can Build the car around a engine and stall & call it street. Not to be Dis respectful Eric is King to me and I've been told and SEE, Non is better. Non! Tech and YB....etc!

What I have now will run a 9. And theirs No Doubt. I think like Daddy Dave. (Non Better is how I think) on what I do and I don't drag. Just Only for $. 8 seconds Martin without NOS or a Cage with a 305 tire). Anything other than that is Void. Better heads and more rpm. What we Did last time & everyone has a Solid. More Rpm and better heads 700 was the base line before everyone wanted a Number. Remember? I'm @ 750 now.