S14 SR with S13 cams, cam timing - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

canadians14sr20det · 05-10-2019, 07:30 PM

Hey everyone, weird issue came up at the dyno. Car ran great, made good power. 377whp on a Mustang dyno.

What's weird is the car made that power at 23psi, which seems like it should be making more power than 377 for that boost level. Turbo is a gt3076 with .86 ar on a full race manifold, so no issues with turbo being out of efficiency.

What I'm wondering is if my cam setup is causing me problems. I'm running BC stage 2 s13 cams (RWD s13 sr20det block, s14 head, vct deleted). I have stock cam sprockets, so not sure if the cam timing is correct. I feel like my setup should be in the 450whp range, could cam timing cost me 75 HP?

Anyone have any thoughts?

Kingtal0n · 05-12-2019, 06:49 AM

need to see dyno graph,

generally from a dynojet,

with smoothing set to zero
and an a/f curve visible

Any other dyno and you can adjust the power down or up as see fit.
Still worth a look if you have it.

Look at torque curve, where does torque fall...

jedi03 · 05-13-2019, 08:50 AM

i thought the degree on the cams was different s13 to s14...

*brndck* · 05-13-2019, 05:43 PM

yeah dialing in the cam gears can have a big impact on performance.

canadians14sr20det · 06-04-2019, 10:13 AM

So started degreeing the cams last night. Based on BC's specs, looks like they were retarded by about 15 degrees on the crankshaft.

Both the head and block have been decked and I'm using a 1.1mm headgasket, but that amount out seems like a lot. The cam gears have enough adjustment in them to compensate, but does that seem right? Is this a manufacturing error? Has anyone else seen this with BC cams?

derass · 06-05-2019, 12:34 AM

Aren't BC cams for SR20 notorious for being poorly degreed right from the factory?

And that Tomei, JWT and HKS are all much better in that regard?

BC valvetrain stuff is all pretty cheap compared to the competition. So maybe you get what you pay for with them.

*brndck* · 06-05-2019, 08:33 AM

BC was known for being way off on their cam timing for a number of years. I thought the issue had been corrected, but how old is the set of cams you're using?

canadians14sr20det · 06-05-2019, 09:50 AM

Cams were purchased new as of April this year.

So tried to start the car with the degree settings I came up with. Car wouldn't start and ran like shit. Contacted Brian Crower and they asked if I was using a hydraulic lifter setup (I am running hydraulic lifters). Turns out you can't degree a cam with hydraulic lifters.

The lifter can compress ~0.040" so trying to degree a cam at 0.050 lift is basically impossible.

So I guess I'm buying a single solid lifter to do the degreeing. Either that or I'll just say fuck it and guess and check cam timing settings against dyno runs lol

05-10-2019, 07:30 PM	#1
canadians14sr20det Join Date: Oct 2011 Location: Canada Posts: 42 Trader Rating: (0) Feedback Score: 0 reviews	S14 SR with S13 cams, cam timing Hey everyone, weird issue came up at the dyno. Car ran great, made good power. 377whp on a Mustang dyno. What's weird is the car made that power at 23psi, which seems like it should be making more power than 377 for that boost level. Turbo is a gt3076 with .86 ar on a full race manifold, so no issues with turbo being out of efficiency. What I'm wondering is if my cam setup is causing me problems. I'm running BC stage 2 s13 cams (RWD s13 sr20det block, s14 head, vct deleted). I have stock cam sprockets, so not sure if the cam timing is correct. I feel like my setup should be in the 450whp range, could cam timing cost me 75 HP? Anyone have any thoughts?

05-12-2019, 06:49 AM	#2
Kingtal0n Post Whore! Join Date: Jul 2005 Location: South Florida Age: 41 Posts: 4,828 Trader Rating: (17) Feedback Score: 17 reviews	need to see dyno graph, generally from a dynojet, with smoothing set to zero and an a/f curve visible Any other dyno and you can adjust the power down or up as see fit. Still worth a look if you have it. Look at torque curve, where does torque fall...

05-13-2019, 08:50 AM	#3
jedi03 Nissanaholic! Join Date: Jul 2008 Location: albuquerque Posts: 1,836 Trader Rating: (8) Feedback Score: 8 reviews	i thought the degree on the cams was different s13 to s14...

06-04-2019, 10:13 AM	#5
canadians14sr20det Join Date: Oct 2011 Location: Canada Posts: 42 Trader Rating: (0) Feedback Score: 0 reviews	So started degreeing the cams last night. Based on BC's specs, looks like they were retarded by about 15 degrees on the crankshaft. Both the head and block have been decked and I'm using a 1.1mm headgasket, but that amount out seems like a lot. The cam gears have enough adjustment in them to compensate, but does that seem right? Is this a manufacturing error? Has anyone else seen this with BC cams?

06-05-2019, 12:34 AM	#6
derass Zilvia FREAK! Join Date: Jun 2010 Location: Toronto, ON Age: 36 Posts: 1,182 Trader Rating: (0) Feedback Score: 0 reviews	Aren't BC cams for SR20 notorious for being poorly degreed right from the factory? And that Tomei, JWT and HKS are all much better in that regard? BC valvetrain stuff is all pretty cheap compared to the competition. So maybe you get what you pay for with them.

06-05-2019, 09:50 AM	#8
canadians14sr20det Join Date: Oct 2011 Location: Canada Posts: 42 Trader Rating: (0) Feedback Score: 0 reviews	Cams were purchased new as of April this year. So tried to start the car with the degree settings I came up with. Car wouldn't start and ran like shit. Contacted Brian Crower and they asked if I was using a hydraulic lifter setup (I am running hydraulic lifters). Turns out you can't degree a cam with hydraulic lifters. The lifter can compress ~0.040" so trying to degree a cam at 0.050 lift is basically impossible. So I guess I'm buying a single solid lifter to do the degreeing. Either that or I'll just say fuck it and guess and check cam timing settings against dyno runs lol