So its been about two years now since i rebuilt my single slammer... for anyone that was following the build, its still running! (haha) Anyway, the compression is still at 200Psi with 11.1 CP pistons. It doesnt smoke anything but black. Tuned with a SAFC on a dyno with the air fuel monitor. I Gained 33% power from stock. Something i was wondering was that i was reading up on the cam that i have because i think it is possibly going flat. The top end ticks alot cold and warm. I did not replace the rocker arms or rocker arm assembly. and have checked valve lash several times going off of stock lash numbers, would the valve lash be different with the different cam? Something that i read was that the 262 was compatible for boosted motors.(reduces boost lag, and make it spool faster) and that is what i have in my car that is n/a. Would that affect how it would run with no boost? and would i be able to run a 272, it said must have higher compression and something else that i do have. Anything will help. Thanks!

 

most of the cams that i have ever seen usually have lower lift for a turbo setup, mainly because it is useless on a turbo car to have an extreme lift cam due to them forcing the air in. but on an na setup you would want a higher lift cam to let the air come in more smoothly. im not sure if your problem is the cam, but you would def gain power with a high comp na cam over something that is designed for a mild cam that cam be used for turbo/na applications. im not sure how na/turbo cams differ as far as duration go, but im pretty sure somebody on here can fill you in

im pretty sure there is a difference in valve overlap on both as-well, (when both intake and exhaust valves are open at once)

i would recommend a better tuning solution, along with an adjustable cam gear if you don't all ready have one

 

Thanks for the input! I do already have a adjustable Cam gear. I have the motor retarted alot right now and always have... It will Ping if i have the timing normal. I just dont want to spend 6 bucks a gallon for race fuel. inless im gonna run it. which i just replaced my horrible clicking axles. Coming spring will run her all out

 

Anymore opinions will be greatly appriacated

 

Another thing i just thought of was how do i check to see if the timing was set for Vtec and not regular... somewhere i read that there is two different ways to time the motor... it was done at the shop that built the motor and i dont know how to find out or what to look for.

 

well, i think what they mean is there are 2 types of timing.. Cam timing and ignition timing..

For ignition timing, you need a timing light, and you time it to stock (I believe 16 degrees BTDC.. its been a while since I timed one).. But for spark ADVANCE (When the spark goes off as RPMs increase) would have to be changed by chipping/tuning the ECU...

Cam timing is done by a belt, and controls the action of the valves in relation to piston position..

and yes.. VTEC will have a different spark advance... but all that is stored in the ECU, and controlled automatically

 

alright thank you for replying... I dont know much about the whole timing thing but i do know that the cam gear it self is turned back i think close to 10 degrees if i remember right... When the motor was first done and broke in, i took it out and got on it and it made a weird pinging noise. but it was only when the motor was under a load like low RPM's in second and third gear. i then took it back to the shop and they retarted it and it went away.

 

If your engine was tuned properly it should not come close to requiring more than premium fuel. You need to have it properly tuned with a chipped ECU. You cam timing looks to be WAY off also.

 

that is not cam timing that was adjusted.. that was ignition timing.. what you heard was knock or pre-detonation.. caused by a few different things, but in your case, looks like the ignition advance was too hardcore for the gas you use...

you ARE using premium, right?

if you arent using premium with this setup, then THAT is why your ignition needed to be pushed back, or you are not getting enough fuel to your motor, causing it to lean out

 

Different manufactures have their own specific valve lash requirements. Some are the same as stock also. If they had to retard the mechanical timing then you lost a lot of power out of a N/A car. You should have had it tuned properly and not just hacked.

To answer your question correctly about different timing with VTEC and NON-VTEC: The mechanical timing for NON-VTEC is adjusted by having everything at TDC and the horizontal marks on the cam sprocket being lined up with the top of the head where the valve cover sits.

On VTEC models mechanical timing is set where a special mark on the cam sprocket is lined up with a pointer on the rear timing cover. Being sure that everything is at TDC of course...