Whats going on everybody, just got signed up to this bored through a friend in my f-body club, so I figured id get your input on this question...


Another friend of mine is giving me his GM 847 cam , never used. Ive heard some damn good things about it, seen some good numbers it puts down by itself (in person no doubt)...but im wondering...I want to keep my stock heads...but I want this cam, so im trying to get a rough estimate of what to expect if I ported and flowed my heads to the utmost and stuck this cam in here with a nice little Ed Wright tuning job being that he lives about 40 minutes away...well anyway, anyone have a clue of what is most reasonably going to be put down to the wheels with this , that is EXCLUDING all other bolt on , free mods etc... thanks very much, and nice meeting you all , by the way here are the specs for that cam...

Gm #12370847, here are the fallowing specs:

Duration- I:234/ E:242
Lift- I:539/ E:558
Valve lash- zero/zero
Lobe seperation- 112

With 1.6 rockers the lift is like 59X something but I cant remember, ive slept since then.

 

the 847 is a great cam, you'll put down a great amount of power, especially with the 1.6 rockers. However, you definitely will be best with at least ported stockers. The 847 makes some crazy good numbers with good flowing heads. If you could afford AFR 195s (I know I can't) you'd see some excellent numbers.

 

I'm scared to ask how much they are...but im going to anyway, whats the average price for these heads?

 

It varies, but I haven't seen a new set for under $2000

 

What do you think about a Hotcam? I was a few clicks away from getting the kit today. The cam pro number is 24502586. The kit itself is 12480002.

Worth the money?

If i do purchase them, would stock ported heads work?

-Scott
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'95 Firehawk. Red on red.
**Nitto 555's; BMR LCA's; HAL Generation F series shocks/front springs on the way **

 

The hotcam kit is great for an otherwise stock motor, especially if you want it in a daily driver car. The cam sounds great, and offers much more power than the stocker does. I personally would go with a Comp XE 224 grind in an otherwise stock motor, but the hotcam kit is an excellent choice as well, it offers some great bang for the buck. It will run fine on totally stock heads, even better on ported stockers. I'd also recommend a tune by Bryan Herter at PCMforless, he's very well known for his Hotcam tune. Check out www.pcmforless.com, you can get your PCM tuned for $100.

 

It is a daily driver and is basically stock now. However i have some rather "large" plans for it and i do own another car with only 30k miles on it. Would this cam no longer be that good?

I'm not very understanding of specs on a cam (i know basically what is better then others, and what the numbers are, but i have problems making choices based ont he numbers).

What cam do you recommend for a car that is looking to accomplish a good 450 RWHP and after that if its not fast enough for me, even more?

-Scott
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'95 Firehawk. Red on red.
**Nitto 555's; BMR LCA's; HAL Generation F series shocks/front springs on the way **

 

The ideal cam changes drastically when you throw a power adder into the mix. For a naturally aspirated motor with no extra cubes, you will want to flow as much air as possible (lift) while keeping the valves open for as long as possible (duration). However, cams with huge numbers like this can often be choked off by crappy stock heads, which is why it's better to keep your cam in the 220s with duration at most, if you're still on stock heads. Remember that cams are cheap, and you can always sell one and swap in another without losing much money. If you're doing the install yourself, you'll probably swap a cam every two years depending on how your motor changes. I'm about to swap in my second cam, I'll be throwing a comp 224 114 grind in place of my crane 214 112...

It really depends on if you're planning to go with a power adder or not. If you're going to do nitrous, you'll want a very wide split cam like a 224/236. The 847 is actually a very good nitrous cam, as well. For forced induction like a turbo or supercharger, it's imperative to keep the intake duration down and the lift as high as possible. The object of forced induction is to cram as much pressurized air as possible into the combustion chamber, so you will want the valves to be open very wide, but only open for a short amount of time so that the pressurized air doesn't bleed off. This will occur if the valve is open for too long.

If you want to make good power with 350 cubes, you really can't beat a Comp 306 or a GM 847 with some good heads. However, it'll be pretty hard to hit 450rwhp in a stock cube LT1. If you're planning on stroking her, you'll want at least a 306 to hit that kind of power, preferably in a 396 cube motor. With spray, the 224/236 makes excellent power. You're best bet to hit 450RWHP cheap is to go with either CNC ported heads/ported stock heads and a rough cam like a 306 or 847. After that and a tune, you should be set to run a wet 100 shot of nitrous oxide. That should bring you up and over 450RWHP. Good luck!

 

Alright, that was great advice. However, i do not plan on getting headwork anytime and when i do it will most likley be ported stock heads. Should i get the 847 still? Will it work fine for a while on stock heads and then ported stock heads? or should i get that hot cam i talked about above and port the heads when i get some more cash? (In your opinion that is, obviously i'm going to do whatever feels right )

-Scott
__________

'95 Firehawk. Red on red.
**Nitto 555's; BMR LCA's; HAL Generation F series shocks/front springs on the way **

 

Well with cams like the 847 or 306, you've also got to think about their power range (something I neglected to mention before sorry)... those cams are both on a 112 lobe seperation angel grind, so you'll have to rev higher to get to their powerband. This puts a lot more stress on your bottom-end, and you'll need a pretty large stall torque converter and possibly some rear gears as well. On the pro side, the bigger cams will probably make around 340-350 RWHP but will jump right up to around 400 rwhp when you let them breathe better through the heads. The smaller cams like the hotcam and the XE 224/230 will make about the same power on stock heads, but will only jump to around 360-370 RWHP when you change your heads. If it were me, I would probably do the Comp XE 224/230 114 LSA grind. It's pretty much the perfect cam for stock heads. When it comes to heads, they're something you won't want to replace twice. Your cam, however, can be replaced as many times as you want to go through the pita of doing the removal/install.

Cliff notes:
- The 847 would require several mods to run right in an otherwise stock car (stall, tuning, maybe gears) and would need to be revved higher
- The 847 will make almost equal power (10-15 more rwhp) to the Hotcam on stock heads, but the hotcam will not need to rev as high to hit it's powerband
- On ported heads, the 847 will make around 30-40 more rwhp than the hotcam


So in summary, my advice would be to go with the Hotcam, or better yet the XE 224/230 cam on a stock motor, get her tuned, and go on with other mods from there. The cam will ad a good amount of power with a tune. Once you swap in ported heads, go ahead and change over to an 847 or 306 to make the REAL power that you want

Hope this helps

 

Stock heads will flow relatively close to the AFR's when they are ported to there maximum potential. The Hotcam will not be able to reach your 450HP goal period! It won't reach 400 most likely. If your looking for 450HP out of a stock cube LT-1 the 847 or a custom grind would be best. A custom grind from cmotorsports with some killer lift and 233/239 or maybe even more duration should get you into the ballpark of 450HP.

 

Alright, thanks guys.

 

No problem.. just tryin to help as best I can

 

Agreed, in fact AFR210's with a good engine setup, GM847 and a few other goodies would be even better. This is definitely a fast food drive-thru flower destroyer and when it kicks in, you know it...and so does the car behind you

 

I seen a much much greater improvement on stock heads with the 847 than 10-15 but I'm sure this is a generic benchmark. Every car is a little different. Hotcam was the cam of choice I guess about 5 yrs ago, seen people do good with it, I couldn't be happy with a baby-cam though, even 5 yrs ago. More time goes by the smarter the cam mfg's get it seems.

 

My 847 cam got here a couple of days go... I'll be installing it on stock unported heads and intake. I'll be sure to let you know how it goes...

BTW, for a cam like the 847, you may also need to buy a spare vac canister to help out with braking... It's not always needed, but I'm going to be putting one in just in case....

 

I ran a hotcam forever in my impala ss's 409 LT4 Stroker.

It made about 400 RWHP and 450 RWTQ. My 4350 lb Impy ran 12.0's @ 113mph on motor and 10.90's @ 124-125mph with a 200 shot.

I just recently broke my timing chain and have since pulled my 409cid motor and did a re ring and re bering and am converting to solid roller.

Hoping for 500 RWHP N/A and over 750 RWHP on the juice!

 

Would the 847 and 306 still work for a daily driver?

 

right on, heres the deal....

A friend of mine ports heads for a hobby, really cool guy...well he did another friend of mines heads in his lt1 t/a...put down 392 at the wheels in about 90 degree weather, with a smaller cam than mine , (I told him i have an 847 cam, and he actually told me he wants to upgrade to the 847 cam in light of these dyno numbers with his heads)...so ive decided to have this man kick it up a notch and do my heads also...lol, except i want him to go crazy and get as much out of my heads as possible. So when all this gets done, ill be sure to update and let everyone know whats up!

 

Yea let us know what you put down....