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400smb_s10 03-01-2012 04:21 PM

Cam Question
 
I just purchased a Cam this morning at the auto parts store for my 400 sbc and they suggested this one for me

288 dur 443 lift and 110 LSA

Will this work good with my stock 400?

any input will be appreciated

Thanks
Ed

techinspector1 03-01-2012 04:51 PM

Quote:

Originally Posted by 400smb_s10
Will this work good with my stock 400?

I doubt it. Depends on the static compression ratio of the motor.

cobalt327 03-01-2012 05:29 PM

Quote:

Originally Posted by 400smb_s10
I just purchased a Cam this morning at the auto parts store for my 400 sbc and they suggested this one for me

288 dur 443 lift and 110 LSA

Will this work good with my stock 400?

any input will be appreciated

Thanks
Ed

Need to know the gear ratio/stall speed, weight, CR, what heads you have, intake and exhaust system, what you expect it to do/how it'll be used, and anything else pertaining to it that's known.

What cam is this? Specs? I'd expect the cam to have around 230 degrees @ 0.050", but that's just a guess. I'd also guess that the dynamic CR is gonna be low. At least there shouldn't be a problem w/detonation, but power could suffer especially the bottom end. The displacement makes up for this a little, but it still may well be quite a mismatch, depending on what you have.

BigEd36 03-01-2012 07:06 PM

What is the duration @ .050"? It seems like a lot of advertised duration for only being .443 lift.

400smb_s10 03-01-2012 07:29 PM

Stall speed is stock. Rear gears 3.73 tranny is a 700r4. Comp ratio is 9.0:1. Its for my street truck. I just want it to be able to letter rip once and a while.

Heads are 3973493 1.94 1.5

4bbl 600 cfm Qjet carb

400smb_s10 03-01-2012 07:40 PM

Hydraulic Flat Tappet, Advertised Duration 266/266, Lift .440/.440

this is the one that i was told to get but all they had was the 288/288 duration and .443/.443 lift so that is the one that I was told would work good

Mr. P-Body 03-02-2012 06:58 AM

All cam grinders have a different method of measuring "advertised" duration. For a more "straight-forward" comparison, the @.050 numbers are more useful. Also, each cam grinder has a different "approach" to making power and the corresponding lobe designs or "shapes'. Not all cams are "equal", even if their "@.050" and lift/LSA numbers are the "same".

That being said, what is the brand name and part number? That's the best way to determine if this cam will suit your needs.

Jim

400smb_s10 03-02-2012 09:49 AM

Duration @ .050" 214 int 214 Exh

SAE duration 287 287

Lobe spread 105 115

lash Hydraulic

Valve Lift ".444 ".444

Cam Lift ".296 ".296

The maker of the cam is MAHLE GROUP and the part number is 229-1987

Hope this give you all the info needed

Thanks for all the input so far

Mr. P-Body 03-02-2012 11:47 AM

Good. The manufacturer is Camshaft Machine in Illinois (they may have relocated). it is a "generi-grind" sold by several vendors, including Melling, Elgin, Edelbrock, Mahle, Wolverine, etc. (all marketers, none are cam grinders). Currently, CMC "soes" most of the flat-tappet hydraulic V8 grinds for MOSTcam sellers including Comp and Crower. Of course, Comp, Crower, Lunati all supply their "own" masters and the grinds are propietery.

This is a mild performance grind. It should offer a pretty smooth idle and will be fine with a "stock" converter. For a little better top-end performance, use "Z/28" (or similar) valve springs. NO "rotators" on the exhaust valves!!! Stick with 1.5 rockers. If you do upgrade the springs, a 1.6 rocker on the exhaust "side" will pick you up some performance. Most modern grinds are "dual pattern". This one is a "single" pattern (both lobes "look" alike).

Comp's old 260H grind is CLOSE. It's 212 @ .050. It has an LSA of 110, though. The stated power range for the Comp cam is "1,200 - 5,200". I suspect this cam would bring the power "in" a tad sooner (the LSA) and not be quite so "peaky" as the Comp, "spreading" the power to the same upper limit. Important to note, differences in performance between the two would be minimal with a grind this "small".

For a 400, this would be a "torque" grind, probably running out of "breath" closer to 4,800 than 5,200. What exactly do you want it (the engine) to "do"?

Jim

techinspector1 03-02-2012 12:19 PM

If your static compression ratio is truly 9.00:1, then the dynamic compression ratio with this cam will be 8.09:1. (intake valve closes at 32 degrees ABDC).When I read your first post, I thought the motor would be a typical low compression boat anchor (around 8:1).

That cam will work fine on pump gas and yield decent power. If you want more low end, use a cam that's a little bit smaller, to raise the DCR some. Maybe a cam with 5-7 degrees less at 0.050".

Are you paying attention to the squish?

F-BIRD'88 03-02-2012 01:51 PM

That cam will work very well for your purpose. It will make more power than stock , expecially with headers and improved exhaust.

re 1.6 ratio rockers on a SBC.
The 1.6 rockers go on the intake side if you want a bit more power from high ratio rockers. ( you gain a small amount of top end power with the increased intake lift, especially if the cam is mild, especially if the heads have been ported. The exhaust side on a SBC head responds more to a duration change.
Often adding extra exhaust valve lift w a rocker ratio swap , shows no gain or reduces power.

keep the 1.5s on the ex side

400smb_s10 03-02-2012 02:04 PM

Ok so I should swap out all the springs to 1.6? or just the intake and intake rockers?

I also ment to mention that the exhaust is 1 3/4" shorty headers into 3' exhaust no cats and glass packs

I want this engine to work well for me. maybe take it to the track on a saturday night but I mostly want it to have a little more ummph then stock. I would like it to be a nice cruizer motor but when i want to get up and scram I will be able to do so.

cobalt327 03-02-2012 02:34 PM

Quote:

Originally Posted by 400smb_s10
Duration @ .050" 214 int 214 Exh

SAE duration 287 287

Lobe spread 105 115

lash Hydraulic

Valve Lift ".444 ".444

Cam Lift ".296 ".296

The maker of the cam is MAHLE GROUP and the part number is 229-1987

Hope this give you all the info needed

Thanks for all the input so far

Considering this was a cam hat was chosen because the "right" cam wasn't available (not usually the way you'd like to go about picking a cam, as I'm sure you would agree), it isn't a bad choice. The lobes are gentle (lot of advertised duration to the amount of lift) so it will be easy on the valve train components, but it will give away some lift "under the curve" that is offered by the fast lobe cams like the Comp XE-series and the Lunati Voodoo series cams. But given the sad state of affairs regarding the current "over the counter" motor oil additive packages, having a less aggressive lobe isn't necessarily a bad thing.

TI has run the DCR for you and deemed it to be OK, so all that is left is to get it installed and broken in. THIS Wiki page has a few articles that could be of some use to you, like:

Adjust valves
Camshaft install tips and tricks
Valve train points to check

Good luck.http://www.chevelles.com/forums/imag...s/thumbsup.gif

techinspector1 03-02-2012 04:12 PM

Quote:

Originally Posted by 400smb_s10
Ok so I should swap out all the springs to 1.6? or just the intake and intake rockers?

I also ment to mention that the exhaust is 1 3/4" shorty headers into 3' exhaust no cats and glass packs

I want this engine to work well for me. maybe take it to the track on a saturday night but I mostly want it to have a little more ummph then stock. I would like it to be a nice cruizer motor but when i want to get up and scram I will be able to do so.

On most of the Dynosims I have run, the motor will pick up only single digit gains (less than 10 hp) with higher ratio rockers. Plus, there is more strain on the whole valvetrain with them. If you were racing in some competitive venue and needed to gain a headlight rim on your competitors, and had exhausted every other avenue of gaining a few hp, I might tend to recommend higher ratio rockers. But if this is in any way a street driver, leave the rocker ratio alone. That's my best advice.

Shorty headers will work better than stock cast iron manifolds, but will be short on power when compared to long-tube, tuned headers.

With 9.00:1 SCR, this motor will not be a world beater. It will make good power with a stock converter, but if you want to "get up and scram", you're building the wrong motor.

F-BIRD'88 03-02-2012 05:21 PM

From your confused response re; 1.6 rockers, just use the 1.5 rockers. They are just fine.
If you want it to really scream get some L-31 vortec heads and a vortec style 4 bbl intake manifold for your 400.
Big big difference in "truck power and torque" from stock 400 SBC heads.
the stock 400 heads are lame. Now the cam can work.

Don't forget to hang on :D


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