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Tech / General EngineIs your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!
I'm in the process of building 305 with LT1 heads and intake that are actually ready to be installed - did all conversion stuff. but i can't figure out which cam and why i should choose. LT1 heads are with 2.00/1.55 valves so propably limited with lift to like .440/.450 or even less? Any help or ideas ? My goal is to make 305 with LT1 heads (small bet with my friend) and reach atleast 305 at crank.
I think Lt1 heads can take a lot more lift, I believe it was around 550. The lt4 hotcam is 525 and it doesn't require any modification if I remember correctly
I think Lt1 heads can take a lot more lift, I believe it was around 550. The lt4 hotcam is 525 and it doesn't require any modification if I remember correctly
But on a small 305 bore the valves are dangerously close to the cylinder walls. I have no idea how close everything is with 2.00 valves considering 1.94 valves are close. Never measured it out myself, I don't know if I'd advise on using those heads on a 305.
It's unfortunate that those heads have the bigger valves. Besides the bore clearance issue, the stock 1.94/1.50 combo would probably flow better due to less bore shrouding. Unless of course your heads are ported also.....then you'll more than recover the shrouding loss. Consider fly-cutting the top edge of the bores to help things.
305 fwhp will be a walk in the park no matter what cam you choose, as long as your intake and exhaust doesn't restrict it. What's the vehicle application....weight, gearing, trans, TC stall, tire size, daily driver, drag, roadrace...? desired rpm power peak? rpm limit?
It is Stock weight 3rd gen, LT1 intake with 2x52 TB, long headers, de-cat with flowmaster exhaust, 2100 TC, 3.32 gears, th700, all controled by Megasquirt, daily driver on 255/60/15 tires. As ia mentioned above i seek for 305 HP before hitting 5000RPM on crank, if more power is more then welcome
my heads are 2.00/1.55 valves casting 10128374, block is 0.020 bored, after measuring max valve lift i can go as much as 0.500" on intake and 0.525" on ext lift
my heads are 2.00/1.55 valves casting 10128374, block is 0.020 bored, after measuring max valve lift i can go as much as 0.500" on intake and 0.525" on ext lift
best regards
Are you planning to run the stock springs and retainers? You really should upgrade to make use of any decent cam. Plus, the modified retainers that come with the better kits will allow at least .550" lift, which opens your cam options tremendously. Example: http://www.alexsparts.com/lt1-valve-...s-spring-base/
If you want to use your stock retainers, you can grind .050" or so from the bottom of the retainer to increase clearance to the valvestem seal at max lift; google "ghetto grind".
What's the compression ratio going to be? deck clearance, head gasket thickness, head chamber cc?
You will have to max out your cam choice to hit 300whp. The LT1 doesn't make hp like the TPI makes torque or the LS1 makes hp. It's a blend of the two.
I had a cam only LT1 make 325whp with headers/rockers/EWP and a ****-poor tune. But that's 350 cubes. You'll need to maximize the bolt ons to hit your number.
Most Cam only LT1s with their 350cc dyno 320-360whp. 360 being T56s and every bolt on you can think of. Autos are almost all below 340, and again with 350 cubes.
Good luck.
Originally Posted by novaderrik
people actually go thru the effort of putting LT1 heads on a 305?
why? in the end, it's still just a 305..
Why do you wash your car? in the end, it's still just a camaro...
Last edited by Vanilla Ice; 01-15-2016 at 03:36 PM.
You will have to max out your cam choice to hit 300whp. The LT1 doesn't make hp like the TPI makes torque or the LS1 makes hp. It's a blend of the two.
I had a cam only LT1 make 325whp with headers/rockers/EWP and a ****-poor tune. But that's 350 cubes. You'll need to maximize the bolt ons to hit your number.
Most Cam only LT1s with their 350cc dyno 320-360whp. 360 being T56s and every bolt on you can think of. Autos are almost all below 340, and again with 350 cubes.
...
He specified 305 hp at the crank. Making that will be about as difficult as falling out of bed.
well, friend of mine have engine dyno so that is not a problem just 5 kilometers trip. as for cam i will go with this one http://www.summitracing.com/int/parts/lun-10120304lk/ (i have non roller block) and only thing i'm not sure of are stock LT1 springs will handle it? guideplates will be installed.
planing to advance the cam on timing chain 2 degrees
as for 0,050 spring install i do have these lock on the shelf just in case.
compresion will be around 9,5, pistons are flat top with 4 valve reliefs, 58cc heads (will check after resurfacing), gasket is 1,5mm before head install.
well, friend of mine have engine dyno so that is not a problem just 5 kilometers trip. as for cam i will go with this one http://www.summitracing.com/int/parts/lun-10120304lk/ (i have non roller block) and only thing i'm not sure of are stock LT1 springs will handle it? guideplates will be installed.
planing to advance the cam on timing chain 2 degrees
as for 0,050 spring install i do have these lock on the shelf just in case.
compresion will be around 9,5, pistons are flat top with 4 valve reliefs, 58cc heads (will check after resurfacing), gasket is 1,5mm before head install.
best regards
WASyL, that cam would be a huge mistake, given your VERY mild TC and gearing, and your 5000 rpm target. It will win your dyno bet, but will be useless in the car,.....and IF it holds together to 6500 rpm to even see its power peak. You should be targeting a cam with 264-270 deg intake duration (212-218 deg at .050" tappet lift). Even less if you want to limit it to 5000 rpm. And....you'll probably lose your dyno bet if you're not willing to rev it beyond 5000.
Oh....and stock LT1 springs will not control that cam to reach its powerband. They will, however, be adequate for the milder cams I mentioned. When new, they are good to about 5500-5700 rpm in the LT1 engine.
Forget about using that 290 deg Lunati cam. It's strictly a drag race cam for high compression, steep-geared race cars with bigger cube motors. Horrible choice for your car. The most aggressive I would go in that Lunati line is this one: http://www.summitracing.com/parts/lun-80350lk/overview/ It would peak about 5800 rpm in your 305 with the short-runner LT1 manifold.
Here are some other options suited to 305 flat tappet engines, but they will make less power than the "265" Lunati I linked: http://www.summitracing.com/parts/su...make/Chevrolet http://www.summitracing.com/parts/su...make/Chevrolet
Add about 800 rpm to their "basic operation range" to account for your LT1/305 as compared to their dual-plane/350 assumption. Your stock LT1 valve springs will be good for those mild flat tappet cams.
the one You said is way to big, oh and i just found out my friend is selling 4.11 gears so i bought them
best regards
You're obviously not putting the correct parameters into desktop dyno. LT1 manifold is single plane.
Regardless, DD is a cool toy to see the effect of changing a parameter or two, not to spec an engine, especially when you don't fully understand every input's effect.
You're either a troll or just stubborn. You're obviously not here for help, so I'm done. Good luck
Why do you wash your car? in the end, it's still just a camaro...
i rarely wash my Camaro- maybe once a year, and only if i decide to go do some hooning on gravel roads the day after it rains and i don't want a steady stream of sand and gravel falling on me when i change the oil or something..
to wash it more often than that makes about as much sense as putting an LT1 top end on a 305 instead of just swapping the whole damn thing in..
Last edited by novaderrik; 01-17-2016 at 11:15 AM.
12-21-2015, 02:45 PM
