Max cam before interference

[beatrod]

Iv looked the other conversations and came up empty handed.. Whats the max lift with a factory short block and boport big valve head before its an interference engine? Have a 2.5 cam in it, am i already there?

[Stinger]

Yes, you're already there.

[beatrod]

What would the biggest cam i could run and stiil be non interference be? Just out of curiousity.. Im gonna run whats in it regardless lol

[88turbobird]

Bo has stage 3 and 4 cams on his site. I believe the stage 3 cam can be ran with a stage 3 head (big valves, beehive springs, HLA's, etc.) without further machining. The stage 4 is a solid roller cam but I don't know what else would be needed to run that cam. His website should specify what each one needs or is recommended to have

[beatrod]

No i already have the stage 3/big valve head from him. Has a 2.5 cam. I was asking at what point it becomes an interference engine.

[88turbobird]

I understand. I didn't do a good job clarifying in my original post. I brought up the other cams as examples of going larger (than your current 2.5 cam) that still wouldn't cause interference with your current stage 3 head. I honestly don't know that limit or all the things involved to figure it out. Maybe give Bo a call? He might be able to give you an idea

[beatrod]

Wait, so your saying the 2.5 cam and big valves.. If the timing belt snaps.. Wont touch the pistons?

[88turbobird]

I don't know the lift on the 2.5 cam so I can't say with 100% confidence but unless you have an extremely shaved deck and flat top pistons, I don't believe you have an interference concern there. I believe that once you start approaching .500 lift (??) on the cam, you're getting into dangerous territory if the belt snaps. Again, not 100% sure on the cam lift number

[Stinger]

It's not just lift but also duration, as it matters how far the valve moves, and also WHEN it moves.

Bo is the only one qualified to answer this question with certainty.

[beatrod]

Right. Makes sense. Il probably ask him just out of curiosity now if your not sure either stinger. Thanks a ton! Also, have any experience with the quick time 2.3 to tko bell housing? Says 9" clutch but the factory for na i was reading is 9 1/16 and the turbo clutch is 9 1/4.... Im wondering if thats the better way to go or if the sbf bell with the adapter plate would be better.. Dont plan on going past 400 if even that is reached, but im not thinking the borg or even a world class would like clutch dumps to much lol wont be on drag tires or even at the strip probably ever but i do drive hard on the street now and then.. I know youv said tons of times the t5 would be ok but for how long ya know.. Maybe im over thinking the transmission a bit...

[Stinger]

You won't break the t5 from raw power, especially on street tires. You could possibly damage one on a missed shift but that sort of holds true for any transmission if you're missing a shift at wide open throttle.

Obviously I can't make the decision for auto or manual trans, my personal opinion is automatic transmissions are pretty boring on the street so is your goal to have a fun street car or something else?

We are a Holley dealer and they own QuickTime so we may be able to get you some sort of deal on one of those if you decide to go that way.

[beatrod]

Yea i wasnt thinking the power would break it once its moving, more the shock of dumping clutches lol but yea just a fun streetcar i can get in an beat on whenever i want. Something i know is going to get me back home 99% of the time. If i do end up going the tko route il surely get it through you then since il be getting the clutch from you and most likely the flywgeel too. Il see if this borg dont granade to quickly first i suppose.

[beatrod]

This is what bo said when i asked him


"Any increase in lift or duration over stock will make it an interference engine. So yes, if the belt breaks it will likely bend valves- it's a good idea to stay up on belt maintenance.

Bo"

So there we have it lol

[Stinger]

Got it