Greaseymec

iTrader: (9)

Starting to get back into the game after almost 3 years of battling the effects of a mild stroke, job changes, etc. Would like to get the car to the track more often but would like to improve power just a bit. Still running my A4 tranny but I have a TH400 on the bench and will finish that build off with a trans brake. I will be running a nitrous shot somewhere between 150-200 shot (single nozzle) The heads are LE2 (will be coming off to be touched up a bit with a spring change) 383 cid. Splayed caps, forged crank and H beams. The math works out to be 12.6 static CR. (“0” deck + .039 gasket + JE 181920 pistons) Stock ported intake. Doing the 24x conversion also.
The rest of the car is up to snuff.
My question is about cam selection. Have not been keeping up on the latest and greatest or whats actually been working. I,ve been running a Comp 292 xfi Duration @ .050'' 242° Intake / 248° Exhaust Valve Lift w/1.6 Rockers:.584'' Intake / .579'' Exhaust Lobe Separation Angle:113°
Best time is a mid 11.4 @120 with a 1.54 60’ shifting at 6400. Lots of room for improvement. Heavy hitters please chime in.

Mec

joelster

I had the same cam but the very first batch right after they came out. Mine was on a 114. I ran it on my stock shortblock and shifted at 6900. I got a best of 11.11 at 121.65 with mine. I would run something bigger with a 383 and tighten it up a bit. 246/252 on a 108. Check LE and AI to see if they have something similar.

bowtienut

iTrader: (1)

Glad you're back after that rough journey!

I'm with Joelster.
Mid 240's intake duration with a 108 LSA with about 3 deg advance (105 ICL).
That's just based on the good running setups similar to yours where AI or LE have spec'd the cam. Call either, they'll get it right.
Mid 10's for you for sure

Wicked94Z

iTrader: (26)

Same mid 240s intake, 10 degree split and 106-108 LSA.

Ultradyne has a nice 245* intake lobe, .612 lift and would pair well with bullet's HR310/377 (254* .602 lift) on the exhaust side. 108 LSA installed on a 104.

Greaseymec

iTrader: (9)

How would those grinds work in regards to the juice I intend to spray? Not gonna be a full time nitrous motor by any means. Will be running motor passes for the most part. Just wanna cross over to the dark side every once in a while!

Mec

bowtienut

iTrader: (1)

Those grinds will be fine for moderately sized shots of nitrous, up to 150 shot for sure.
Remember, your engine will still be making 2/3 of its power by NA means, so optimize it for that, and the shot on top of that is just icing on the cake.

Greaseymec

iTrader: (9)

Extreme Golds good enough for these grinds?

Mec

Tony Shepherd

iTrader: (4)

Glad to see you back in the game! Good luck with the new build!

Greaseymec

iTrader: (9)

Thanks Tony! It feels good even to start thinking about working on the car again. I was very tempted when you had your entire induction system for sale a few years back. Should have bought it and sat on it till I needed it! It would have gone great with what I'm working toward. Congrats on you record! Maybe I'll see ya at SAR sometime.

Mec

flyinZ

iTrader: (15)

Congrats on your back in the game! You'll get it right, no doubt. Nice sounding setup too.

BADHAWK51

iTrader: (1)

The cam I'm running. 249/257 .612 107LSA

Greaseymec

iTrader: (9)

Alot of impressive cars and sound advice. Thank you all! Seems like everyone is in the same neighborhood with the grinds. My xfi seems to a bit on the small side in comparison. I would have spun it up a bit higher than 6400 but my data log (AFGS) started leveling out and then dropping back around 6500 showing me a bit of valve float. Those bee hives could not control the cam. Hence the spring change. Probably gonna be giving Lloyd a call soon when I get closer with that part of the build. Most likely will be doing a gear swap (presently 3.89) also along with a bit more stall (presently 3600). Ohhh wait....my mouth is watering! lol

Mec

96capricemgr

iTrader: (1)

Look at Comp's rpm range for the cam, the LT1 pulls past that rpm range, hence the recommended springs don't cut it. Been documented before.
Not a beehive problem it is a Comp's rpm range problem.

Flip through the PSI catalog and give it a good spring and see what it does. If still not happy you will have a better spring for whatever cam comes next.

Greaseymec

iTrader: (9)

Yep. Have visited the issue but took a 3 year long ponder. Will not be using the xfi 292. Extreme Golds are on the to do list. Remeasure pushrod length and change em out if I need to. Definitely a rocker arm change. I,ve been running SA GMP 1.6. NSA rockers on the list. Have guides and studs. Was also considering E85 but...one thing at a time.

Mec

BackInBlack02

iTrader: (4)

Hey John!, long time, hope you're doing better after the stroke, did not know about that. How's it going?

Great to see you back behind the wheel, I still have my LT1 money pit. Btw, I found your cam card, it was not in the cam box, found it loose on one of my tool boxes. Do you still need it?

will send you pm with my # to catch up.

jc

joelster

I wouldn't expect that cam to pull strong to 7k with 383 cubes to feed. I shifted my 350 at 6800-6900. It pulled real hard from 5k-6500 and then tapers off a bit. I still have the motor just sitting here waiting for a new home, with 918 beehives on it. You say you experienced valve float issues. What lifters? What pushrods? What size valves? How did you have the lash set up? I set mine up with zero lash plus 1/16th of a turn. That gives the lifter nearly zero chance of extending the valve open. With a preload of 3/4's of a turn past zero lash you'd see all sorts of problems at higher rpms. I see that sort of lash adjustment recommended by a lot of old school guys.

Greaseymec

iTrader: (9)

Joelster...I resemble the old school remark! lol But none the less, stock LT1 lifters, cant remember pushrod pn, Ferrea valves 2.02/1.60s. Lash is "0" + 1/8th. Planning on using Caddy or ls7 lifters. The last time I checked them the 918s I have installed were down just a bit (by about 10 lbs from the advertised pressures) at max lift. (.600).

Mec

flyinZ

iTrader: (15)

Dumb question, but say, you set your lash at 0 + 1/4 turn..How can you tell, if you would be able to get away with less, like 1/8 turn? Or whether you need a little more, like a 1/2 turn?

Wicked94Z

iTrader: (26)

you set preload to the amount you want the lifter to hang the valve when you start to lose control of the valvetrain. the less the better in my experience.

gregrob

iTrader: (8)

It completely depends on the lifter. I prefer .060-.080 preload unless its a short travel lifter. Then the mfg recommended preload should be followed.