Freshdot

So i installed my bisimoto 2.4 turbo cam at TDC last week without being knowledgable on the areas of cam degreeing. What's the drawback of doing this and then advancing or retarding the valve timing by my tuner on the dyno? isn't that essentially the same concept in the search for max HP during the tune as degreeing prior to getting on the dyno?

siblues

iTrader: (1)

You can tune them that way but its not the correct or mosty efficient way.The tuner will not know where his starting point is so if he belives the cam is at a certain point it may not be.This makes a big difference with bigger valves and lumpy cams lol.

BisimotoAlvin

You can never be sure that the cam is in its correct position until you degree it in. For best performance gains, you should degree in your camshaft like we recommend and expect all of our customers to so.
Degreeing in your camshaft means synchronizing the camshaft's position with the crankshaft. Not necessarily installing it in at Top dead center. A few degrees of misalignment can affect the engine's operation dramatically.

BisimotoAlvin

Although, finding True Top Dead Center is part of the procedure to properly degree a cam.

C_Rock77

And I guarantee that if you're just trying to install camshafts by simply lining up the factory timing marks, you're already off from TRUE TDC.

BisimotoAlvin

Exactly!

If there were no manufacturing tolerances, you would only need to line up the marks on the timing chain sprockets and the cam would be degreed, but with a group of components (the camshaft, crankshaft, timing chain, and sprockets, etc...) all with their own standards and tolerances that when installed, can stack up against you, and like you mentioned you would already be off. In the end, this can lead to drivability concerns and lack performance.

C_Rock77

I've heard figures of ~3 degrees variability in crankshaft timing just from the inherent slop you can have in the camshaft/key/cam gears and the crankshaft/key/cam pulley. On a stock engine, it's no big deal. When you're building a PERFORMANCE engine, it can (and usually will) have an effect.

Not to mention, if you know EXACLTLY where the events happen in the engine timing, the tuner will know more about the adjustments he can make, safely.

ohsnapzafingcu

iTrader: (2)

with higher compression motors, the degreeing helps figure out piston to valve and valve to valve specs. you may not have issues with piston to valve, but if you're using large cams your valve to valve may be an issue.. just something to look at

Natural Aspirations

The cam doesnt know if its degreed or not advancing is advancing and retarding is retarding (best done on a dyno). A cam at factory center lines or manufacturers suggested center lines may or may not have the best results on a dyno. And safe adjustments is a shot in the dark unless you know exactly where the valve is in relation to the piston or the other valve.

The suggestion from the Bisimoto team is quite typical, really of no help to you offering any suggestions didn't even ask what engine you were working with or suggestions.

Sounds like you are working with a SOHC motor when you said CAM, SO valve to valve clerances are of no concern to you.

You have to start somewhere a good way to get things close with limited tools and the engine in the car.

Put a long (clean) screwdriver or other slender metal object down the plug hole and make sure the TDC indication on your belt cover and pulley are accurate. (Older worn pulleys the inner and outer can twist over time and become inaccurate.) Make a new mark on the pulley if necessary.

A lot of Honda engines have a provision to keep the camshaft from spinning while installing a timing belt (I'm not fluent with the SOHC engines they may not) and if your cam manufacturer wasn't too cheap the were kind enough to add the provision into the camshaft. There should be a 5mm hole in the cam rail that will line up with the cam (or close) at TDC.

You now have 3 reference points to start from Crank, Cam and Gear.

Set the crank at TDC

Make sure the cam gear is in alignment with the markings on the head

Loosen the cam gear bolts

Turn the cam until you can align the hole in the cam with the hole in the cam rail. (5mm punch)

Tighten the cam gear bolts to the specified Tq

Rotate the engine a few times and recheck your settings.

This is not an EXACT measurement but should get you quite close and gives you a known point to reference from.

EG1834

With that said, the engine doesn't know or care what the centerlines are in relation to a mark on the crank pulley or on the cam gear(s). The engine only knows when and how far those valves open or close in relation to the position of the piston, and thats something the builder should know as well.

Checking the clearances and degreeing the cam(s) are two different procedures and should BOTH be performed on a performance engine.

Natural Aspirations

It cares if it's significantly off kilter. The engine is already together, your post is meaningless. Your only goal was to twist my words.

With as many engine combinations that have been put together with proper parts, how many have you seen not clearance out fine? No using b18a pistons in an lsvtec is not proper parts, I'm sure there are some odd combinations that will have interference. This is a SOHC (no valve to valve to be concerned with) turbo motor (no domes to worry about). Without more from the OP it is difficult to guarantee anything.

EG1834

LOL, cool it tough guy. You don't have to get so defensive just because someone disagrees with you.

Now, I'm not talking about clearances, I'm talking about the importance of degreeing the cam(s) and I'm suggesting both procedures should be done. Why? Well because I've seen only 1 degree of advance make 25 hp on a boosted engine, and I've seen as much as 2 degrees of error with aftermarket parts. It could have been either or all of the gears or it could have been the camshaft. I've even seen camshafts as much as 4 degrees smaller than advertised, all because I've degreed every camshaft I've ever installed. I would rather see that the centerlines have moved through measurement rather than just trusting the accuracy of the dots and markings on mass production pieces like a OEM balancer/pulley or aftermarket cam gears.

Natural Aspirations

Tough guy? Ok **** head.....

On that engine that gained 25 hp with 1 deg of cam adjustment, how important was degreeing the cam?

If you have degreeded every cam and only seen one off by 4 deg you haven't measured many cams.

racebum

oh, like honda gets right every time?

still correct, aftermarket cams aren't ground for the most part to the same degree or accuracy as honda. couple in shaved blocks and heads and it's really easy to be off a few deg

EG1834

LOL, **** head? What are you, like 13 years old?

On the particular engine I'm talking about, degreeing the cam was pretty critical. It was an 1150hp combo we've built many times and through exhaustive dyno testing, we got a pretty good idea where the engine liked the cam to be installed. The funny thing is, the degrees of advance indicated on the cam gear wouldn't always match the true centerline when measured with a degree wheel and dial indicators. Degreeing the cam saved lots of time chasing lost power had we just lined up the dots.

It doesn't even have to be a combo like that to realize the benefits. If you know what the centerlines truly are, and not what the cam gears tell you, then you can always go right back to it if anything changes, like milling the head.

BTW, I have installed and degreed in well over 100 camshafts.

wunfstgsr

What if the motor is completly oem and stock! i assembled a fresh brand new oem ITR motor from the dealer head and block seperate with the eception of ARP head studs and i didnt degree the cams with a degree wheel, i did use aftermarket cam gears and went with the tdc timing marks on the cam gears only. The motor has been running very strong for 30k miles and also dynoed at 285hp with a jrsc @12psi, my question is how likely is the cam timing off?

Freshdot

back from the dyno..never degreed the cam. made 308 @ factory TDC marks, retarded 2 degrees and made 349 on 21psi late in the RPM range because of my actuator screwing up and not holding boost early on. I have since replaced the actuator and now haul a **** load of more *** at 21psi at 4800 RPM not sure on HP but i'm def making closer to the 400hp mark i was looking for with my greddy 18G seeing no more than 125 IAT's that everyone and their mother doubted.

BUILT D16Z6, internally gated 18G, edelbrock log manifold..FTW!

Natural Aspirations

Great job!

Freshdot

more pics and build thread coming soon!

redline1219

WOW, very impressive numbers, good job! Also great info in here, thanks...

BisimotoAlvin

When did I ever ever say that Honda got it right every time? The only point I am trying to make here is that, it is always recommended by me and by the rest of the team at Bisimoto Engineering to always deegree a camshaft in when installing it. Whether it is our own proprietary designed specification or some cheap "china knock off" camshaft.

BisimotoAlvin

I gave the answer that I gave because this is was a simple discussion of the importance on Degreeing a camshaft. (Something we recommend all of our valued customers do once they purchase a camshaft from us, or a competitor).
If anyone needs to be provided with the step by step procedure to degree a camshaft we can do that, but that falls far beyond the scope of what we do here at Bisimoto Engineering. We at Bisimoto Engineering, engineer, design, and manufacturer high performance products so that the public may enjoy. We make our technology available to everyone. We are not a "ma and pop" shop, although we aid the public as we deem it necessary. Nonetheless, you are entitled to your own opinion and we appreciate the response.

racebum

you didn't

i said honda got it right everytime

their cams are ground with tighter tolerances than a lot of the aftermarket meaning on a 100% stock engine you can install them with stock gears

i don't disagree with you at all, it is a great idea. just saying the reason people have to degree them is usually shaving and or off grinds

BisimotoAlvin

True, but even a stock camshaft can benefit from cam degreeing at 110 degree centerline, and increase performance. I say this because factory camshafts are typically dialed in for a compromise in performance and fuel economy. Thanks for your concordance

Freshdot

now that we have a bisi rep in here....do yo uthink i would have made more HP had I done the degree than the 349?

the way my tuners and I saw it was simple..slap it in at TDC move it forward 2 degrees off the gear..move it back 2 degrees off the gear and see where the gains were made...i was temped to go back 1 more degree but was worried about my piston/valve clearance so i didn't get greedy and stayed very happy with this power.