Any seriously bad issues if I run a mild cam with a 110 LSA?

 

Some info on the motor would be . But if it is a stock TPI motor especially a non-roller motor, the computer more than likely wont like it very much, there is a good amount of cams out there with a 112 LSA which is where you would want to stay for street-ability.

 

IIRC running that lsa would be better off run in open loop and tuned with a wideband. if you decide to go that route i have a good cam for you. its the comp cams xe268 which is 110 lsa for flat tappet depending the year of your motor.

 

The smaller the motor and the more the duration, the bigger the LSA influence becomes (less LSA, think more overlap).

On a 305 with a 270 plus duration a 110 LSA will be harder to tune, then say a 383 and a 260 minus duration.

You have to look at it all, the duration, overlap, LSA, and the rpm operating range. A stick can idle higher then an auto so that can be a deciding factor. Also the total gear/tire combo, if your not in the lower rpm range (lugging along at <1500 rpm) things are not going to be as big of an issue.

 

Here's some info on what I've got.The motor is a 8.5 cr 350, 76cc heads, 1.94/1.5 valvesTPI with 22lb injectors, dual exhaust with stock manifolds700r4 stock converter, with 3.42 rearThe 2 cams I have to choose from are 1. 262/272, 204/214@.050, 420/442 lift, 112 lsa 2. 266/272, 210/216@.050, 440/454 lift, 110 lsaI'm planning to run 1.6 rockers on either cam

 

The 420/442 lift cam is the one I just put in my 305, a little on the small side for a 350.

 

i have experience with the 420/442 in a flat tappet 305. It ran into the 14s. Had alot of gusto for being a small cam. I got all of 5800 out of her. For a street cam it would be nice, but the next stick up you have would be my choice.

 

I'm wanting to run the bigger cam also but I'm concerned about the 110 lsa.Do you think the 1.6 rockers would help the smaller cam in a 350?

 

If I remember correctly with the 1.6 rockers its increased .020" to 440/462, can anybody verify this?

EDIT: By the way the 420/442 cam has a shorter duration but since your a running TPI you wont get much more out of it then the 5500-5800 this cam will give you. My

 

I think I'll scrap the 1.6 rocker idea (anybody want some?) and try the bigger cam with the 110 lsa. The duration between the 2 is very close.

I plan some spirited driving and a few bracket nights but mostly 40 mile highway commutes to work and back. Idle is an issue as I have a auto 700r4.

As a side note this setup is for a fairly light car as in '72 Vega.

Thanks for all the input.

 

ive got the comp xe-286 110 lsa in my speed density 355.15" hg runs great good TQ good street ability. but with the stock runners you run out of hp before the cam gives up. but thats after 5300.

 

110 will work fine with that duration if its MAF sensor car. idle may start to do funny things since the o2 sensor may start picking up extra air in the exhaust and think its lean when its not.

but that cam is small regardless so i dont think you will have problems. A tune would be nice to go along with it as all cars can pick up from a nice tune

speed density systems may require some tweaking with a cam like that

 

the difference with the rocker ratio swap is .031-.033 so your cam spec of
420/442 would be closer to .453/.475which will be fine,i used the old SLP 495/510 with stock springs for a few years..

 

umm lets see 420 in. turns to 448 with 1.6. and the ex. 442 turns to 471. its just simple math.

 

Went with the 110 cam and stock rockers. All seems to be good. Idles fine and drives good. Haven't gotten "into it" yet but so far so good. I do have a SD setup with stock tune.

I discovered the rockers I have are self aligning and the 1.6 roller tips I bought are not. Moral; Check before you buy.