Is anyone running a cam LSA that small on this board, what would be the smallest that can be considered? The car will never have a power adder, have a 3500 Yank ST converter and a 4.11 gear. Heads will flow 315/220@.600 with a lt4 intake, 58MM TB, 36 lb injectors and 11.5/12 to 1 compression 383, will have factory PCM and opti.

I was recommended by a cam manufacturer this solid roller cam

260/270@.050
610/620 lift
108 LSA
installed on a 104

Can I run 12 to 1 with this cam? Will it bleed enough cylinder pressure to run pump gas? I want max power on pump gas N/A

David

 

I would not go with something that tight (108)....mabye if you were running open headers all day long Exhaust becomes alot more critical as you tighten up the LSA. The other thing: I see you keep asking about 12:1 compression. Do some DCR calculations. 12:1 on pump gas (93+) is not going to be a problem if your motor is tuned well. I run over 12:1 on 93 octane and have a considerably smaller cam.

One other suggestion....you may want to back down the duration some on that cam. That is pretty radical. You could make basically the same power with a shorter duration/bigger lift camshaft, along with having better driveability (since you want pump gas, I assume this is a street car), and more torque where it matters. Not sure on how high you plan on reving this motor, that would be useful info as well. 260/270 starts to really move the powerband kinda high for a street car.

Jason

 

If you can make the computer on an LT1 run on the street with that much cam, you are a better man than me.
I would not even attempt that cam with a full Gen 7 DFI, let alone a stock PCM.
I'm guessing you talked to someone at a cam company that is used to dealing with carbed engines. A carbed motor responds a lot differently to camshaft duration than an F/I motor - namely most fuel injection systems do not like a lot of overlap. I reccomend keeping lobe seperation over 113deg; and keeping duration well under 240deg @050 (probably more like under 235) in a street car.

 

Thats not to far off from what my current cam is, my last 2 cam's I've run on 108 and had good luck with them. The higher I spin this cam the fastest it goes, last time out I was shifting at 7600 and going thur the lights at 7900. My heads don't flow anything near yours, I would think if it was put together right it should go easy 9's. As far as driveability I'v only had very little time on the street and my conv is stalling at 6500 right now, was spoz to be 6000. I would also say your going to need a bigger TB, bigger injectors, a lower gear and more stall to make it really work. I guess I just think hardcore anymore

 

Looking at your post Steve, and a huge 260/270, I dont see how that thing is going to run with a 7k rev limit and be making peak power. As for the LSA you can run it in open loop, otherwise the overlap will cause a problem.

 

Thats one other thing you would not what to run this cam with a stock PCM, as I run a FAST ECM.

 

David -- I'm running a 108.9 LSA solid roller in my 383, A4, 3.73's, 3200 stall, Stage IV LT1 heads, 36# injectors, 11.23:1 CR, etc. and have not noticed any problems yet. I was able to get @700 miles on it before the winter weather set in. I bought the heads, intake, cam and solid roller accessories from INTMD8. When he had this combo in his car it dyno'd 453rwhp and 416tq if I remember correctly (m6 car). He would be a good one to get the specifics of this combo from since he had it matched up and does dyno tunes. Hopefully he will read this and chime in.

Pete.

 

. . . . oh yeah. It's a 242/252 .606/.606 cam motion custom grind.

 

Thanks for the suggestions guys, keep em coming. The cam manufacturer stated that this cam will use new steep or fast ramp technology it will peek power at 6800 according to him. reason for the smallish converter is I want it to hook on a 325/50 Drag Radial. The same cam people ground me a very small cam for my previous combination 224.228@.050 and a 112 LSA that was almost as queit as a stocker but ran 89.3 MPH in the 1/8 mile in a 3775 lb six speed z through shorty headers and full exhaust 355 inch engine on a radial tire. I think I will back off some duration, leave it at a 108* LSA. It will be a streeter with A/C and a 4.10 gear in a 9 inch.

David

 

What engine managment are you planning on using? We need to know that. Street car right? Need the info. You may not want to hear this, but I think a 112lsa would be alot better for your planned setup. If you are using the stock PCM setup, you are limited to 7000rpms. Even with a 6800rpm peak, that is still too high for you limit. If you are limited to 7000, i would look at cams peaking ~6500rpms.

Jason

 

It will factory PCM, theyre are guys on this board running 110LSA hydraulic cams with good success. I will call the Manufacturer on Monday and confer further.

David

 

me neither thast wayy big. Leave that or a carb motor You knwo they make carb intakes for LT1s

 

In the past I had ran a hyd roller 242/251 584/592 on a 108 with the stock pcm, best the car went on the stock pcm was 11.7's. Went to a fAST ecm, as at the time there was no user softwear out for tuning. With other changes to the car I had netted a best of 10.54@127, this was at 3250 lbs

 

If you had ED Wright tune the car back then what would it have run? What was the rest of your combination?

 

Fastfatboy
I think you're custom-cam money is better spent on a F.A.S.T or Gen VII DFI system for the car. If you really want to go this fast you are going to need more control over the engine.
think of it this way - how are you gonna run those proposed 36# injectors? The stock PCM is setup for 24# injectors, it is gonna see the engine running super rich with 36# and freak out.
I know that a computer control doesn't sound as exciting as a big cam, but it is gonna net you more in the long run.
Look at squinn - he picked up more than a second from custom programming, no cam can provide you with that kind of gain in power, I don't care what the specs are. Another point here, he picked up a full second from the tuneability of the FAST system, that tells you somthing about how badly the car was running with the stock PCM and that great-big (but smaller than the one you are talking about) cam of his.