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Does anyone have any suggestions on a good cam for a stock 305 motor. I have the motor torn down to refresh it and figured I'd try and see if I could get a better cam in this motor to bump up the horse power and torque .....
Any suggestions would be appreciated.................
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If you're looking for something that will retain stock functioning but give you a bit more power, check out something like the Comp cams XR258HR, it's a 206/212 .480/.487 grind. It'll make power in the same range as stock but probably give you a good 20 more hp. There's also a 212/212 .440/.440 grind that would work well also.
not sure what you had in there for a stock cam.. but I loved the stock LB9 cam I had in my car.. lots of torque and power for a 305. I believe a L98 cam is the same exact grind, just found in some stock 350s.
If you're looking for something that will retain stock functioning but give you a bit more power, check out something like the Comp cams XR258HR, it's a 206/212 .480/.487 grind. It'll make power in the same range as stock but probably give you a good 20 more hp. There's also a 212/212 .440/.440 grind that would work well also.
What was your exact purpose with this motor?
First off let me thankyou for taking the time to answer this post.
OK, what I have is an '85 Iroc motor that came out of a manual car, what I am looking to do is bump up the horse power and torque pretty much retaining most of the stock componets, not looking to make crazy horse power or nothing like that just want a little more kick out of it. This vehicle will not be setup for the 1/4 mile just want something to cruise around in on a Friday or Saturday night. The motor is being dropped into an 84 Trans am also would like something that sounds nice (cam wise). Let me know what you think Thanks again.
ah, so you can't use a roller cam, as was suggested. That '85 motor is a flat tappet style IIRC. Was it the LG4 motor? I think TPI in '85 was brutally rare.
The comp xe256 is a good choice for that. Same low end torque, but it'll rev higher, and make wayyyy more midrange. I'd throw on new 100/300lbs valve springs. You can use the LT4 "kit", for springs and retainers and whatnot. It's cheap as dirty from GM. You can always backcut your valves if you want too. Every little bit helps, and it's a heck of a lot easier to do now.
What Sonix said. I might also suggest the next larger XE262 but that's definitely as far as I'd go with it. With basically stock heads and intake you don't want a lumpy cam. By the time the cam is big enough to be lumpy sounding it's effectively killed any power you're ever likely to get from the motor.
ah, so you can't use a roller cam, as was suggested. That '85 motor is a flat tappet style IIRC. Was it the LG4 motor? I think TPI in '85 was brutally rare.
The comp xe256 is a good choice for that. Same low end torque, but it'll rev higher, and make wayyyy more midrange. I'd throw on new 100/300lbs valve springs. You can use the LT4 "kit", for springs and retainers and whatnot. It's cheap as dirty from GM. You can always backcut your valves if you want too. Every little bit helps, and it's a heck of a lot easier to do now.
okay how much dirty cheap?????
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Quote:
Originally Posted by Sonix
ah, so you can't use a roller cam, as was suggested. That '85 motor is a flat tappet style IIRC. Was it the LG4 motor? I think TPI in '85 was brutally rare.
The comp xe256 is a good choice for that. Same low end torque, but it'll rev higher, and make wayyyy more midrange. I'd throw on new 100/300lbs valve springs. You can use the LT4 "kit", for springs and retainers and whatnot. It's cheap as dirty from GM. You can always backcut your valves if you want too. Every little bit helps, and it's a heck of a lot easier to do now.
oh almost forgot it was an H.O. Carbed motor...
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Quote:
Originally Posted by Damon
What Sonix said. I might also suggest the next larger XE262 but that's definitely as far as I'd go with it. With basically stock heads and intake you don't want a lumpy cam. By the time the cam is big enough to be lumpy sounding it's effectively killed any power you're ever likely to get from the motor.
xe 262 are you running one in your car?????? If so what other goodies do you have????
Last edited by irocgta; 07-16-2006 at 08:34 PM.
Reason: Automerged Doublepost
sorry to jump into this thread, but i'm looking for a cam for my 305 as well but it's an LB9 TPI motor...any ideas?
That blue Iroc you have pictured there is that a factory paint looks pretty rich. Just wanted to know I have an Iroc I want to do in that exact color, would you have the paint code handy????????Thanks.
dont have the exact specs right now on the cam i was running in my 305, but it was a comp cams compu-cam 2050,with a 1.6 rocker and some bolt on parts the
can ran 13.6 in the quarter.
I don't think those lunati cams have 112 LSA's. Might want to check that.
The computer controlled versions from comp have 114 LSA's, which is easier to tune with than the typical 110LSA's.
I had a lunati 60103, but it was in my 350, and it went flat after 1000 miles. I'm not biased against lunati due to this, just a side note. I now have a compxe268.
I'd keep duration below 220* on the intake, or very low in the 220's, for it in a 305. Otherwise it'd be a little too agressive to be pleasant.
Do a search on here for LT4 kit. Vader made a post listing off the parts, springs, retainers, locks, etc. All GM prices. They're half the price of the comp equivalent prices. In Canada GM jacks up the price 200%, so it wasn't economical for me to use.
what about this cam? is it too extreme for my car? i'm getting a whole kit for $100 if i buy it
hydrolic flat tappet cam by General Kinetics, blue printed for the 300/350 Corvette motor.
@ 0.050 Duration - 216/228
nominal duration is 272/282
lift is .454/476
112 degree Centerline
i dont have a clue what any of this means, but i'm getting it all BRAND NEW in box for $100 with the cam, lifters, springs, valve locks, seals, and lube...
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Quote:
Originally Posted by irocgta
That blue Iroc you have pictured there is that a factory paint looks pretty rich. Just wanted to know I have an Iroc I want to do in that exact color, would you have the paint code handy????????Thanks.
factory color from '91. Ultra Blue Metallic, paint code WA 9591
Either one of those would work alright. The corvette one is slightly bigger, but still within reason, and if you get it with all the bells and whistles for $100 (i'm guessing buying from a guy who knows a guy, not the off the shelf price?) that's a good price.
That cam will make peak power at about 4500 rpm and add about 35 hp in a stockish L03 305. With supporting modifications (exhaust, heads, etc) it'll peak at about 5500.
whoa!
ok, I got lost here, original thread poster has an '85 305 block, wanting a flat tappet cam recommendation for a carbed application?
bluezee has a later model TPI motor, wants a roller cam to be used with TPI induction.
ok! i'm up to speed!
blue zee disregard what I said. You don't want a flat tappet cam, it'd be a downgrade in performance, plus you'd need to buy lifters and pushrods. If you get a roller cam, it'd be higher $$, but you don't need to buy lifters and pushrods.... It's still more cash, but the performance is there.
That crane cam doesn't even say if it's a roller or flat tappet cam, but since it says it's for '88-89 TPI cars, i'd guess it's a roller cam. In that case the lift is kinda low for it's duration, give that it's a roller cam.
Casey butts' recommendation is good. Not sure if that lift figure is with 1.6 rockers though...
well I've got a LT4 hotcam in my TPI roller 305 and so far I hate it..
I've basically lost all bottom end torque, it doesn't idle, and power doesn't start till like 2500rpm.. ****ty for a stock TPI that falls flat at 4500.
Brisk:
Runs ****ty for a Stock TPI? Are you stoned? Your engine is FAR from stock...
I just watched your videos, looks like it runs ok. It does idle pretty rough though. The exhaust duration on that cam (228 @ 50?) may be a bit too long for a smooth streetable 305... maybe not such a big deal though because the intake duration is fine.... I think that the cam is not so much the issue here...
It sounds to me like the engine is just BEGGING for more timing. I think that you need a new custom PROM is all. To start with, add 3 to 4 degrees across the entire range for the low RPM's, basically 400 to 2800 RPM, and I'd bet it will idle and begin to pull much better down low.
Also, did you add any more fuel to go along with the increased air flow (provided by the new heads, cam, AND rockers)???? If you did not, you are probably running too lean, which would help to explain the very rough idle.
well I've got a LT4 hotcam in my TPI roller 305 and so far I hate it..
I've basically lost all bottom end torque, it doesn't idle, and power doesn't start till like 2500rpm.. ****ty for a stock TPI that falls flat at 4500.
did you have that car tuned after you installed the cam? if not, that's more than likely your problem
mnorton - keep in mind the 'burnout' vid was from last year when I only had suspension for mods. as for 'stock tpi' I was referring to; plenum, runners, and intake.
I've been learning how to burn proms for a while now.. and have tried several combinations with marginal success. Obviously I havn't had any great success which is why I'm hating my combination. Seriously I'm ready to jam the stock cam back in and toss the lt4 hotcam in the landfill.
Brisk:
Hmmm... I hate to hear that you are so frustrated as to just toss the cam. I didn't realize that the burnouts were pre-cam. I'm assuming the idle video is post-cam.
It sounds like you need to try something different. Maybe that cam with those rockers is just too much for the computer to control well. Have you tried installing the old stock 1.5 rockers to tame the lift? I would... If I'm not mistaken, that would get you back down to a more manageable .492 lift.
I still think that the engine sounds like it wants more timing at idle. And if you are running 19 lb. injectors you probably need a little more fuel, maybe at least raise the fuel pressure to 46-47 psi. What is your injector constant currently set to? What are your BLM's?
If you are hitting a wall at 4500 RPM it's not because of a lack of available air flow through the stock plenum/runners/intake. It's only a 305...
My cam duration specs are similar to yours (214/220), the lifts are lower (452/465), and just a little more timing helped my idle a lot. I'm still working on the fueling part, I need to do some open loop tuning, and then I'll get back to the timing curves.
