Specs:

- D16z6 fully built minus sleeves
- Bisimoto 2.4 cam, JE 9.0:1 compression pistons, Scat rods stock length.

Question: When my car was tuned we retarded cam timing by 2 degrees, my tuner thinks we could have made more power if we kept pulling the timing back, but was worried about clearance issues as I never clayed my motor. How can I figure out how far I can safely retard my cam timing?

Going for a retune with Jeff Evans soon, and want to sort everything out before I get there. Thanks in advance.

 

By claying your motor

 

any way to figure this out after the fact??

 

by taking the head off and claying your motor...

 

Bump! For Bisimoto level 2.4 cam. Great choice.

 

how bout offering advice instead of advertising trolling.

 

Ya..

 

anyone else?

 

Whats specs on the cam..?

What manifold? What turbo? What fuel? What power level? how much boost? need answers..

 

Antime you change cams (or valves) you really need to check v2v and p2v clearances to know what is safe. Most people don't bother with this step but usually stay at 0 so it isnt a problem. You can use the Mike Belben kit from Xenocron that uses dial indicators to measure p2v with the head on, but its expensive (and always out of stock).

 

****, so i suppose claying the motor will be necessary.

 

For what its worth usually retarding the cam is generally safer than advancing it. Roll the dice!

 

it was suggested to me to lock the vtec and retard the cam as much as i can while hand cranking it. once i've reached the point of the engine not moving to then go forward 2 degrees...thoughts?

 

Eh thats hacky. Any positive clearance may not be "enough" clearance. Things stretch at RPM and things heat up and expand too. You would have to guess that the buffer created by backing off 2* is enough clearance. If you had a dial indicator on the valve stem you can measure the clearance between piston and valve.

For me on my B18c with a different cam each degree of cam rotation worked out to be .008" intake and .010" exhaust clearance. So backing off the interference point, or zero clearance would net me .016" intake and .020" exhaust valve clearance. This is still not enough. Of course my numbers wont apply to you at all. Im using them to make a point.

Some say you need at least .060" p2v clearance.

 

i think i'm about to just leave well enough alone at 2* retard and just go see evans.

or put it back to zero and degree the cam, then let him worry about the rest.

 

I dont think you'll have any issues retarding it more than 2...unless this is a higher compression piston with oversized valves?

I've gone to minus 8 before on a Zex 59300 cam on a Vitara/Eagle combo and -6 on a Wiseco 8.5 piston with Eagle Rods.

Hell I've single cam turbo setups come in OFF 2 teeth on the cam in either direction and not had any valve issues.

 

Thanx man, my setup is pretty similar to the wiseco/eagle combo, just slightly higher compression at 9.0 and pending those eagle rods were stock length. Given the information you've provided I'm guessing I'd be safest around -4*

side note, are you Chris by any chance? I'm a friend of Romel Trotman's at lincoln tech, he spoke very highly of you.

 

Yes I'm Chris and I remember Romel from the class he took. Say hi for me

 

dial the cams in...harder with engine in ...but possible. i bet you'll make more power that way rather than tinkering around.

 

yea, i'm gonna degree that sucker before going to evans. and now with the info that xenocron has provided, i can at least feel safe pulling this bitch back up to about 4-5*

thanx all!

 

i was told that the D motor is an interference motor, and this advice could be risky business..thoughts?

 

Pretty much every Honda motor is an interference motor isnt it?

Choices:
- Do like everyone else has said...you can degree it to be certain.
- Keep it where you are at
- Or move it and take some risk.

Like I said before, I dont think you are going to have any interference issues...but to be certain, you know the answer already.

 

Chris are you ever going to get your Cam Degree Fixture Kits in stock?

 

I dont see that car making much more power by going deep into the negative range..
-5 at most..

I'd retard it another -2 and see how the car likes it.. Typically on CAM TIMING, retarding will give you more p2v clearence.. its Advancing that needs to be really looked at..

And speaking of advancing have yall tried to advance timing??

 

no, we didn't try advancing it. ****, it was me who suggested retarding it. honestly, the guy who tuned my car is a fricking scum bag, they did a couple of pulls and called it a day. I have an adjustable cam, FPR, WG actuator, and it was me that had to make all the suggestions on what we should be tinkering with.

hardly did any part throttle tuning either. all he really did was dump fuel across my powerband and sent me on my merry way. which is why i want to get everything in order and see evans.