Camming a 10.3 to 1 350

[Scotthatch]

Yeah, 230* is a little rich for my blood too but everyone has a little different opinion on idle quality and I tend to be a wuss

Didn't the OP specify a hyd/roller?

Yes he did

[Orr89rocz]

The cam only should be big enough to get the job done. It doesnt take much for a high 5000’s rpm peak and 430 hp.

Gm crates do it with the lt4 hotcam. 218/228. Do not need anything near 230+ deg with half decent heads

Though as it sits with the 112 lc this cam and the head flow it would just hit the HP target the problem with this cam is the intake at .050 does not open until 3 degrees after tdc .... this I sure was done for emissions back in the 90's ... though I'm sure vacuum would be good it's probably leaving a lot of low end torque on the table and it has been pointed out its a heavy car ...

If you advance it it will do better torque wise but then will come up short on the target HP number ...

With more flow then we have this would work ....

Yeah its a compromised cam and older design but just using it as an example that it doesnt take a huge cam to do what needs done by the op
I tuned 2 setups with the hotcam and another with similar durations at .050 but much more modern and faster lobes. They all work well, drive near stock like with hint of lope and make decent power for what it is depending on heads and intake type.

[Scotthatch]

The cam only should be big enough to get the job done. It doesnt take much for a high 5000’s rpm peak and 430 hp.

Gm crates do it with the lt4 hotcam. 218/228. Do not need anything near 230+ deg with half decent heads

Though as it sits with the 112 lc this cam and the head flow it would just hit the HP target the problem with this cam is the intake at .050 does not open until 3 degrees after tdc .... this I sure was done for emissions back in the 90's ... though I'm sure vacuum would be good it's probably leaving a lot of low end torque on the table and it has been pointed out its a heavy car ...

If you advance it it will do better torque wise but then will come up short on the target HP number ...

With more flow then we have this would work ....

Yeah its a compromised cam and older design but just using it as an example that it doesnt take a huge cam to do what needs done by the op
I tuned 2 setups with the hotcam and another with similar durations at .050 but much more modern and faster lobes. They all work well, drive near stock like with hint of lope and make decent power for what it is depending on heads and intake type.

Should drive like stock as it is a stock cam...

Years ago at the speed shop I had a guy come in that was going to build a line of sbc powered trikes and he needed a camshaft .... I did everything I could to kill torque on it ... lower lift ... wide lobe center ( 114 I think it was) no overlap at .050 slow ramps ... he got it built and it ran well ( had to there is no weight) the next one in line his buddy talked him into a "better" cam ... bigger ..tight lobe center high lift .... when it was done he came back to talk to me because the trike was a handful ..... he said he already broke the frame on this one and the one before just went and drove ... I'm not sure he understood my explanation

[Orr89rocz]

Well its a performance parts cam thru gm but regardless what i mean by stock, i mean like stock L98 or LT1 gen 2 cam. Had very mild characteristics. Idled smooth, sounded slightly hopped up but not to telling. All around not bad for a cam you can pick up used in classifieds for 100-150$ sometimes

[groberts101]

Obvious that we all have very different views of what a toy driver is. Not many choose to drive something like this 7/365 so I'd call it a toy you'd want to drive to work and the grocery store on a daily basis. NOT a daily driver with A/C cruise, lumbar support seats and stereo while idling near stock. But to each their own and everything in between.

And I myself love slightly too much cam in advanced, maybe even upwards of 6 degrees, with a little extra overlap to help fatten up the sweet spot, and then tamed right back down with a dual plane to again.. fatten up the sweet spot.

Super fat base timed ignition curve along with larger than average pump shot and go have fun with it. Tune it right and 14 inches of manifold vacuum is more than plenty with a vac canister. I know for fact many of the cams being rec'd here could be tuned for upwards of 18" of manifold vacuum. Too tame for my taste but again.. to each their own.

[Scotthatch]

Well its a performance parts cam thru gm but regardless what i mean by stock, i mean like stock L98 or LT1 gen 2 cam. Had very mild characteristics. Idled smooth, sounded slightly hopped up but not to telling. All around not bad for a cam you can pick up used in classifieds for 100-150$ sometimes

Years ago I used the old GM off-road cam a lot ... and not that long ago I helped a dirt track guy and used that cam because it was cheap and I had experience with how it worked ..... I am not about perfect I am about getting the job done so it works as needed .... I have a old reverse cooled lt1 in the back of the shop that I may build for the shop truck so cheap build I keep looking at it when I grab parts and thinking about what my best plan would be

[Scotthatch]

Obvious that we all have very different views of what a toy driver is. Not many choose to drive something like this 7/365 so I'd call it a toy you'd want to drive to work and the grocery store on a daily basis. NOT a daily driver with A/C cruise, lumbar support seats and stereo while idling near stock. But to each their own and everything in between.

And I myself love slightly too much cam in advanced, maybe even upwards of 6 degrees, with a little extra overlap to help fatten up the sweet spot, and then tamed right back down with a dual plane to again.. fatten up the sweet spot.

Super fat base timed ignition curve along with larger than average pump shot and go have fun with it. Tune it right and 14 inches of manifold vacuum is more than plenty with a vac canister.

I agree .... keep hoping the OP will let us know what's OK with him ..... I have driven cars I thought were unacceptable but they thought were just fine ...

[DrillDawg]

Other people have told me that very thing about a motor I am dealing with in my shop now ... breathing on this is too much for the short block .... but I am not a big fan of power curves that never get to peak always seems like a failure on planing .... the engine is not together yet so what's the choice ? Get a different cam ? Limit flow? Build a better short block? Or limit rpm like you said?

If you have to much low end torque you just fry the tires, limit the top end with a rpm chip, timing retard chip, and you might want to slow the advance curve if you are still frying the tires.

Not really what we are talking about here .........

And that seems like a convoluted way to set up a car ... to me it's like driving a square peg into a round hole with a bfh

I've had to deal with a lot of street type of cars that can not ET due to traction issues and killing low end torque was always the answer. And if HP and RPM will kill a build that's already done, you limit those factors and most of the time that type of engine has limited low end torque anyway.

[groberts101]

Lol.. it's a street car. You can never have too much torque! Don't hamstring it. Get a better(or more) tire.. and learn how to drive it.

[Scotthatch]

Lol.. it's a street car. You can never have too much torque! Don't hamstring it. Get a better(or more) tire.. and learn how to drive it.

That's not completely true .....

I have a Nova here now that's twin turbo and at 21 lbs of boost is near 1000 HP ..... it is a light big tire street car .... I have taken out gear and gone from th400 to glide ... I am not happy about how it hooks at all ... even turning down the boost to 17 does not help .... sometimes it is hard to find a short path to what works ....

[77cruiser]

Lol.. it's a street car. You can never have too much torque! Don't hamstring it. Get a better(or more) tire.. and learn how to drive it.

Right foot controls the torque on the street.

[427dart]

Keep it simple! It's a street cruiser that will spend much of it's life under 4500 RPM in some kind of traffic.
I say something like the Comp Cams XE-274 on a 110 LCA hydro roller. Great power and torque!

[Orr89rocz]

Lol.. it's a street car. You can never have too much torque! Don't hamstring it. Get a better(or more) tire.. and learn how to drive it.

That's not completely true .....

I have a Nova here now that's twin turbo and at 21 lbs of boost is near 1000 HP ..... it is a light big tire street car .... I have taken out gear and gone from th400 to glide ... I am not happy about how it hooks at all ... even turning down the boost to 17 does not help .... sometimes it is hard to find a short path to what works ....

Mine with th400 and 3.42 gear on a 275 pro radial hooks fine at the 1000 whp mark... if you leave it in 3rd gear and are going 50-60 mph roll lol. It will hold lower power in 2nd but my car was 3800 lbs in street trim

[cjperformance]

Post your selection of a cam for a aluminum headed 350 with a 180 intake runner and that has 10.3 to 1 compression. Car is a street car with a 4 speed and 4:10 gears. Nice cruiser. Hoping for 430 horse out of a roller set up.

Camtech hydro roller that is really streetable in a 350" engine like that for a streeter.
286˚288˚ adv , 230˚233˚@.050" .526".537" with 1.5 rocker 110˚ lsa.

Not sure where this thread is heading right now... but


A cam like this is going to make like 461.5 HP which is past target .... that is not always a bad thing but then the question comes up as to what will the short block be OK with?

The other problem is this pushes the rpm up to peak HP at 6929 rpm and peak torque at 5364 rpm since it is manual and 410 gear in some ways that fits the car but at this point it's getting to be more of a toy then a driver

No , in a real world combo like that it peaks around 6200/6300 , operates vac boosted brakes, happily cruises at 2200+ without being a pig in a M/T car, pulls top gear from 1300rpm of course not making big tq/hp right there but does it, works drives and tunes to a nice power/econ tune running that divided plenum rpm airgap (certainly does not require 800cfm ) using a 650cfm carb, and has a bit if a gnarly idle that is probably not going to be opposed to by most guys with a 67 car running 4spd and 4.10 rear.

[Scotthatch]

Camtech hydro roller that is really streetable in a 350" engine like that for a streeter.
286˚288˚ adv , 230˚233˚@.050" .526".537" with 1.5 rocker 110˚ lsa.

Not sure where this thread is heading right now... but


A cam like this is going to make like 461.5 HP which is past target .... that is not always a bad thing but then the question comes up as to what will the short block be OK with?

The other problem is this pushes the rpm up to peak HP at 6929 rpm and peak torque at 5364 rpm since it is manual and 410 gear in some ways that fits the car but at this point it's getting to be more of a toy then a driver

No , in a real world combo like that it peaks around 6200/6300 , operates vac boosted brakes, happily cruises at 2200+ without being a pig in a M/T car, pulls top gear from 1300rpm of course not making big tq/hp right there but does it, works drives and tunes to a nice power/econ tune running that divided plenum rpm airgap (certainly does not require 800cfm ) using a 650cfm carb, and has a bit if a gnarly idle that is probably not going to be opposed to by most guys with a 67 car running 4spd and 4.10 rear.

OK ...

The carb is why it's peaking low ...

Lots of ways to get rpm down ... what HP did it make and what was head flow?