LT1 camshaft suggestions?

[firstgenaddict]

The crower solid roller we put in the black RS/Z was a 636 gross lift intake and exhaust 277 intake duration and 281 exhaust on a 112 lobe separation,
The heads were basically stock 186's with a little blend on the 3 angle valve job, and gasket matched I gave the flow numbers from .100 to .700 in .100 increments to Dave Crower and he asked if I wanted to pull a number on a dyno or what I was doing. 69 Z28 with 4.10 a 26.5" tall tire and /2.52 first -
I told him I was not going to second guess his recommendations and I could care less about much other than it was going into a 69 Z28 which has power brakes.

The car made 13" vacuum at 1000 RPM and pulled hard through 7000RPM, was really EASY to drive. Can someone embed the player I can't get it to work.
https://youtu.be/e4BZbpTA_wI

[NorCam]

Dave Crower is a smart man. He's the one who put me onto that 00471 grind after I told him that I was building a 69/Z.

[firstgenaddict]

Dave Crower designs the cam ramps to slowly set the valves onto the seats - this way it doesn't hammer the seats into the heads. He told me that with the runner volume of the 186's you have to get the valve up quickly and hold it there as long as possible in order to get the air in and that the velocity and VE would remain high because of the small runner cross section.

[LT1vette]

Hi... Opinions will come from all OVER!!!

Spend some time either, learning how to set up the LT1 cam or find an Old time racer to set the car up for you.
You are "beating a dead horse" on what you think is a good cam, what I think, what the next guy thinks...

My thought, after I did some of the second thinking on changing to something "BETTER",....
GM/CHEVY had wayyyyy more $$ than I did, why not try to perfect what they said worked??

If you are going racing, then this is not the website to look for an answer. If it's going to be your weekend driver, the bang for the $$ is there, IT'S IN THE TUNING!!

Been there, done that, VERY SORRY I DIDN'T LISTEN...

[firstgenaddict]

I am sure that if circumstances(technology, costs, etc) had allowed Chevrolet to run roller cams in the engines of the 60's they would have - they sure ran them beginning in 1987 when they had the opportunity.

I doubt that Chevrolet / Pratt & Miller /K-tech were seeking opinions when they went to Crower Cams and specifically Dave Crower to design the cams for the C5R and C6R racing programs.

That being said... My opinion is that anyone building an engine call the professionals at CROWER CAMS or the cam manufacturer of your choosing and have them spec the cam for your application.

[Zman1969]

Originally Posted by L78_Nova

The GM off road cams are nice if you have lots of rear gear.
They are lumpy old school, No bottom end torque, goodness

And VERY easy on valve springs !!

I run a 140 with 1.7 rockers in my 72 nova 350 flat tops zero decked with 4.33 rear and fast burn heads.
11.60's @ 113.
Definitely needs good fuel. I add a couple gallons of 100 LL to a tank of 91.
Gary

thanks L78 nova simple answer of being low on torque

Originally Posted by NorCam

Your posts are confusing?

You ask for advice on an LT-1 cam, then jump in saying hold up...nothing lumpy? Then you post again the next day asking about two camshafts known as the lumpiest of the DZ-302 profiles?

Read that whatever way you want...

Jump in? I didn't ask about Lumpy sounding cam for the LT1. You jumped in with if someone wants a lumpy cam... so your post wasn't related to my initial post was it?

I appreciate all the other suggestions here guys Lynn I'm leaning towards the LT1 cam but was initially concerned about LT1 detonation as the 302's kind of missed that with the stock cam, right now my 302 with 3.31s and stock exhaust manifolds is a bit of a pig to get moving

[NorCam]

Originally Posted by Zman1969

so your post wasn't related to my initial post was it?

Yes...it was actually. Many of the cams that you were provided including the so-called "several" I suggested were very suitable choices for an LT1 build. The roller cam I suggested with its 236/240 duration is an excellent hydraulic roller camshaft for an LT1 and makes enough vacuum to handle power brakes as well as support the RS headlamp operations. You did also say in your original post that you had no issues with a roller cam...did you not?

I have no issues going back flat tappet or even a street roller

Well? That was a really good street roller. If it's a little too lumpy for you, then understand that the entire line of hydraulic rollers is easily bumped down a step or two to what becomes a very mild-mannered street cam, and is totally forgiving on the valve train. Something the guys at Crower could have easily helped you out with. Seriously...they work with everyday people to help select camshafts all the time.

All snide aside...good luck with your engine build.

[Zman1969]

thanks for clearing that up but with roller will be able to keep the stock Z rocker covers?
I don't see anyway you can with the poly locks

[NorCam]

I have successfully run Crower 86050S Short Poly Locks with 1.50 Roller Rockers under stock Z/28 covers on more than one occasion. For added clearance, I've also added thicker cork gaskets such as the ones from Summit, or have doubled up with a set of regular cork gaskets and glued them together. Lots of clearance then but you can often get away with just the short poly locks noted above.

If you end up picking a roller cam that doesn't need as much spring, you could likely run a set of stock long slot rockers and use the regular lock nuts. I simply use roller rockers and screw-in studs as a performance preference, as well as added insurance against pulling a stud and maybe dropping a valve. There are plenty of reasons to upgrade the stock valve train on 186 heads when one has the chance. Especially when buzzing these things up to and/or over 6500 rpm as they were intended.

This one has roller rockers and poly locks with stock valve covers. If you look to the right side, you can see the thicker gaskets under those covers. (most people would have no idea it's rollerized, but I know, and that's all that matters)