[Big Mouse]

I'm thinking about putting a Lunati 60112 Hyd Roller (cut on the small base circle) in my 383. This is a "rowdy" street car that will get occasional track time.

The cam specs are (Intake/Exhaust):
231/239° @ 0.050"
282/290° Adv.
0.535/0.550 lift
110 LSA / 106 ICL

The engine is a 10.4:1 stroker 383 sbc ('69 4-bolt 010 block and 5.7" rods). Flat top pistons w/ reliefs. Edelbrock RPM heads and intake. Holley 650HP carb, Headers + Exhaust. Tremec TKO600 (0.64 OD) with 3.73's and 29" tires, MSD Ignition. Rev Limiter probably around 6250 - in case I miss a shift...

Is this cam about right for my combo? Will I be OK cruising at 60 mph in OD at 2k RPM's? 110 vs. 112 LSA?

[Clint Cummins]

hey,

My first concern would be the edges of the rod bolts touching or striking the cam lobes because of the larger stroke 383 crank.

Hopefully one of these guys have done a similar build to iron the details out.

[Big Mouse]

Originally Posted by Clint Cummins

My first concern would be the edges of the rod bolts touching or striking the cam lobes because of the larger stroke 383 crank.

I'm currently running a small base circle hydraulic flat tappet - which seems to give me plenty of clearance. So, hopefully, all will be well with the new cam.

I'm having my machinist double check everything - just to be safe (including clearances, valve-train geometry and piston-to-valve clearance). FWIW, the engine is coming out to investigate low compression on one cylinder - so it's a good time to make the change. There are about 1k miles on the setup right now.

I just want to make sure this cam will pull pretty well down low. I also want to cruise at 1800 to 2000 RPM's - and I want the OD to work for this... Lunati assures me it will. I'm looking for some street experience to confirm.

[Clint Cummins]

Originally Posted by Big Mouse

I just want to make sure this cam will pull pretty well down low. I also want to cruise at 1800 to 2000 RPM's - and I want the OD to work for this... Lunati assures me it will. I'm looking for some street experience to confirm.

That cam with 231/239° @ 0.050" will be somewhat over-cammed for an engine cruising at 1800 to 2000 RPM's...

The reference for that cam = 3,000-7,000 rpms power range...

Reference link:

http://www.crankshaftcoalition.com/w..._compatibility

I am not for sure the 3.73's and 29" tires is going to help enough.

Does this help any?

[Clint Cummins]

hey,

Does Lunati have a similar cam in the 221/229° @ 0.050" 2,000-6,300 range?

[68NovaSS]

Originally Posted by Clint Cummins

hey,

My first concern would be the edges of the rod bolts touching or striking the cam lobes because of the larger stroke 383 crank.

Hopefully one of these guys have done a similar build to iron the details out.

You said you're using a small base circle cam, you're good there. If you want good throttle response from cruise, rethink the cam.

[Big Mouse]

Yes, it helps. Thanks so far guys.

Originally Posted by Clint Cummins

Does Lunati have a similar cam in the 221/229° @ 0.050" 2,000-6,300 range?

Well, of the manufacturer's suggestions, Howards and Crower come the closest to that range. The recommendations I've received thus far have clumped into two groupings:

• 224 to 225 @ 0.05" INTAKE 230 to 232 EXHAUST (which includes Crower and Howards)
• 230 to 232 @ 0.05" INTAKE 236 to 239 EXHAUST (which includes Lunati and Comp)

Howards seems to be in the middle with lower lift and longer durations on their cams --- and Howards INSISTS that I use the 112 LSA. Comp, Lunati, and Crower all said 110 LSA.

Howards suggest their 110245-12 cam:
224/230° @ 0.05"
280/292 Adv
0.501"/0.509" with 1.5 ratio
112/106

I currently have a 230/236 @.05" 274/286 adv .49/.49 hydraulic flat tappet. It does just fine cruising in OD at 1800 RPM's. It will accelerate mildly from there (no downshift for hills).

I want a roller equivalent that is one step up from my current cam (XE274h). Suggestions?

[eric32]

I am running that exact lunati cam in my 86 s10 but mine is a 350ci and I have no issues with mine but I don't have overdrive like you do so cruising down the highway at 55mph I am around 2500 rpm.

I am running 3:73 gears with a 3000/3500 stall and if I am in drive in town and I am under 2000 rpm the engine does not do very well so I just down shift to 2nd gear when I need to but highway wise that cam is killer with a good setup.

I have very crisp instant throttle response and the torque is way awesome and with yours being a 383 it would be even more. As stated if your wanting to use the overdrive for highway you might want to go smaller on the cam. Mine does not like it under 2000 rpm very well and it will drive decent but not good.

Hope that might help out in your decision you could go with the next smaller voodoo cam the 60111 it would be a really good cam as well. Guarantee there would not be a big drastic difference in horse power between the 60111 and 60112 cams but there would be a mild difference in how it would run in your combo. The other options you have look good as others have stated as well.
Eric

[Big Mouse]

That is great feedback - thank you. I'm hoping the extra cubic inches will help me a bit. I'm also running a 4-hole spacer which may help boost the low end signal. Good stuff!

[67-4-fun]

the 112 LSA will give you more vacume keeping the valves closed longer than a 110 LSA, so a 112 will have abit more low end torque for lower rpm crusing.. 110 still not bad but dont go lower than that, 109 and lower will be a little to much overlap and a little loss of compression as well