Really low vac with 274 cams

[dsmgsx98]

So I installed some Dsm graveyard 274 reground cams strait up and trying to figure out why the my vacuum is at -8 at 900rpm. I thought they would still have a vac of around -12 to -14 can someone that has these cams help me out

 

[Boomdeeze]

i pull 16 with stock is that bad?

No thats not bad but usually with bigger cams, you lose vacuum.

 

[JusMX141]

retarded the exhaust 2 degrees and and advanced the intake 2 degrees. my vacuum is almost 15 now so i assume if I went another degree or so it might drop a bit more?

Who called that?

I wouldn't go any more than necessary or you start to screw up the overlap altogether.

 

[Boomdeeze]

Who called that?

I wouldn't go any more than necessary or you start to screw up the overlap altogether.

Me??? I said it after I talked to delta!!!

 

[Sandman817]

So if use 274 owners advanced intake 2* and retard the exhaust cam 2* we will have good drive-ability without noticing a sacrifice in power up top?

 

[dsmgsx98]

So if use 274 owners advanced intake 2* and retard the exhaust cam 2* we will have good drive-ability without noticing a sacrifice in power up top?

I would bet its not going to pull as hard up top!

 

[dsmarmy777gst]

hahaha I wish i could tell you how well it pulls. but when i took off down the road i started to hear a knocking sound.. luckily it was coming from the rear of the car so I went home and pulled off my tire, caliper and rotor (driver side rear) and my damn emergency brake pad assembly came apart on me! everything was rusted to hell and broke. Funny thing is i replaced that last spring. So I'll blame it on the salt from this winter.. But when i did drive it, it felt smoother, and no idling issues.
No hard brakes either!

 

[JusMX141]

Me??? I said it after I talked to delta!!!

That's not exactly what I was thinking.

....you may do better on your own just by retarding the exhaust cam a little or advancing the intake...or both.

...and I didn't have to call anyone.

 

[dsmgsx98]

hahaha I wish i could tell you how well it pulls. but when i took off down the road i started to hear a knocking sound.. luckily it was coming from the rear of the car so I went home and pulled off my tire, caliper and rotor (driver side rear) and my damn emergency brake pad assembly came apart on me! everything was rusted to hell and broke. Funny thing is i replaced that last spring. So I'll blame it on the salt from this winter.. But when i did drive it, it felt smoother, and no idling issues.
No hard brakes either!

So they don't lope at idle anymore????

 

[Boomdeeze]

hahaha I wish i could tell you how well it pulls. but when i took off down the road i started to hear a knocking sound.. luckily it was coming from the rear of the car so I went home and pulled off my tire, caliper and rotor (driver side rear) and my damn emergency brake pad assembly came apart on me! everything was rusted to hell and broke. Funny thing is i replaced that last spring. So I'll blame it on the salt from this winter.. But when i did drive it, it felt smoother, and no idling issues.
No hard brakes either!

My motor is out right now but I just set my cams to this and cant wait to test it out.

 

[Sandman817]

what about the previous "bucking" issues you were having at low speeds? Honestly, i would rather sacrifice some top end power for better drive-ability on the streets. Also, how was your idle after you adjusting your valve timing? Did it still lope like a big cam or was it a little less subtle?

 

[Boomdeeze]

That's not exactly what I was thinking.



...and I didn't have to call anyone.

Ya you got me

 

[dsmarmy777gst]

It still loped hard. It just had a bit more strength to it, if that makes sense. Usually it will idle fine then want to die. This time it was idling strong around 900 rpms or so and not struggling like it normally would. I had some BC 272s in an I never had idle problems, but they didn't lope as hard and i didnt have as much mid range punch.

 

[JusMX141]

Excessive idle lope- to the point where it tries to shut the engine off- is a result of having too lean of an idle. Add a little fuel and I think you'll see that smooth right out.

Ya you got me

Just kidding, man...you actually took the initiative to call the manufacturer and post up the advice they gave, so you're got some rep points headed your way.

 

[dsmarmy777gst]

Yeah I don't know exactly what's up with mine. My afrs at idle bounce around mid 14s low 15s and that's with a lot of fuel added. I've just had the poor idle since I installed the 274s and adjusting the gears those couple degrees seemed to help.

 

[dsmgsx98]

Yeah I don't know exactly what's up with mine. My afrs at idle bounce around mid 14s low 15s and that's with a lot of fuel added. I've just had the poor idle since I installed the 274s and adjusting the gears those couple degrees seemed to help.

Let us know when you make a WOT pull with the new adjusted cam gears

Guess I need to make a WTB thread for some cam gears!

 

[dsmgsx98]

Excessive idle lope- to the point where it tries to shut the engine off- is a result of having too lean of an idle. Add a little fuel and I think you'll see that smooth right out.


Just kidding, man...you actually took the initiative to call the manufacturer and post up the advice they gave, so you're got some rep points headed your way.

Its cool I gave both of you guys Rep points but I don't think it counts cause I don't have Rep points, . Oh well I tried! !!

 

[Boomdeeze]

Thanks guys and I am curious to hear about the WOT pull after those adjustments were made. And you should definently buy some adjustable cam gears to help out your idle.

 

[Sandman817]

Guess I need to make a WTB thread for some cam gears!

Not if i make it first!! hahah just playing

 

[dsmgsx98]

Not if i make it first!! hahah just playing

I heard that,

 

[Sandman817]

So how is the drive-ability with the advance/retard compared to installing them straight up? Very curious since our cams are definitely a high rpm cam, just curios as to how the low/mid range is now after adjusting the timing

 

[dsmarmy777gst]

I'm going to go do some pulls tomorrow as soon as I put in some new e-brake hardware haha

 

[Boomdeeze]

Any pulls yet?

 

[dsmarmy777gst]

Any pulls yet?

Parts store didn't order the brake hardware. It'll be in tomorrow morning. I'll throw it on and go do some. Sorry about the wait!

 

[Boomdeeze]

Parts store didn't order the brake hardware. It'll be in tomorrow morning. I'll throw it on and go do some. Sorry about the wait!

Your killin me biggie smalls!!!

 

[16g DSM]

I don't even have these cams and i want to know how they perform with the adjustments ! good thread!