Stock 304, Guide to choosing a camshaft

[drewVHSS]

like i said i dont know much about the 284, but if those are the gears your gonna run then i think that cam will suit you. 286 would go on strike if you asked it for that kind of low down torque.

When i looked at the rpm ranges i thought the 286 would be a bit much, 3 grand clutch dump to get moving everywhere i go wouldn't be my idea of a car i can put up with in traffic despite me being a truckie for a living!

 

[Aussiepride5L]

"Factory 308 VH SS M21 Factory LSD 3.08:1 10 bolt salisbury. No mouse motor in mine from factory champ" ....lol.. love it..!!

Yeah, in that case, I'd go for a custom grind as you can define Exactly what you want from the cam, otherwise the 284 would be good. The 278 is a roller cam, but with a larger LSA 1000-5000rpm, I dont see why Crane couldnt make you a cam with that particular grind...as they do stipulate anyway that they offer that service. I'd email Crane, give them your engine specs and where you want the power and they will give you a custom grind to suit..! Best option.

 

[ari666]

just looking at the specs: 284 duration, 112 sep and 480 lift (with 1.65 ST2032's it'd be 495) im leaning towards this as being a little on the large side for those diff gears. but should be a nice cam. i reckon it may bog a little down low.

 

[Aussiepride5L]

just looking at the specs: 284 duration, 112 sep and 480 lift (with 1.65 ST2032's it'd be 495) im leaning towards this as being a little on the large side for those diff gears. but should be a nice cam. i reckon it may bog a little down low.

This is true to some degree, I agree with you as the 284 is the largest cam you can go without raising the compression, but he has the added raised compression already which will help in that area. Also it has a slightly larger LSA @ 112 rather than the 286 @ 110. If he was to order the 284 with a LSA of 113 or 114, then that would be a VERY nice cam...!! I would order a split duration cam at 218/228 @ 0.50", 113 LSA. That cam would be the ticket...!! But again, that's custom grind, as thus why I reckon order a custom grind.
The 276 is a nice cam but it runs out of puff at 4500. Its ok if he will drive on lower torque, but if he wants to rev, then it wont do. The 284 is a nice compromise especially with the added compression.

 

[Aussiepride5L]

I guess i should've elaborated a bit more:
The original owner had the motor rebuilt in '96. Both my brother (prev owner to me) and I have barely put 40 thousand kays on it and it's still a healthy motor.
When the original owner had it rebuilt to rectify a scuffed bore, he had the block decked 30 thou and bored out 40 thou. the rebuild also included flat-tops and moly rings. $10k was the price tag for the whole rebuild if that gives an idea of the work done back in '96
I have no idea what the compression ratio is but if i tune it to how it used to be for leaded fuel it pings off it's head on 98 with lead additive (100 octane metro with additive doesn't ping) so untill i pull the L34 heads off i can only guess it's around its 10.somthing:1 area.
Hadn't considered what thickness gaskets, the reciept/build sheet for the engine doesn't say what thickness is currently on the motor either so quench factor isn't known untill i pull the heads.
I already have Yella Terra ST2032's in the ol girl and will be re-using them. 1.6 ratio AFAIK

will be retaining original 10 bolt 3.08:1 ratio diff
Currently running an M21 but am on the hunt for a T5G box and when i find one a YT Ultra light flywheel will be going on in place of the standard original one.
The VN conversion will involve the VN heads i have on a shelf and the harrop dual plane i have also laying on a shelf, pacemakers (already sourced)
The heads haven't been shaved which from the highish unknown CR i have atm, well this would probably be a good thing.
I didn't want a stupid wild engine that's a pain in day to day driving. It currently has a bit of lope at idle, quite easy to putt in traffic but also breaks loose when you want it to. It seems to run out of puff at around 4400-4600 rpm.
Am quite happy with running factory HEI dizzy for now, i have a injection perfection TB for when i EFI it much later on but i'm only looking to run carby initially and unless i have major tuning issues, probably wont be in any hurry to throw the EFI hardware on.
I can't think of anything else to add for now that might help.

Sounds as though he's already running the 276....

 

[drewVHSS]

This is true to some degree, I agree with you as the 284 is the largest cam you can go without raising the compression, but he has the added raised compression already which will help in that area. Also it has a slightly larger LSA @ 112 rather than the 286 @ 110. If he was to order the 284 with a LSA of 113 or 114, then that would be a VERY nice cam...!! I would order a split duration cam at 218/228 @ 0.50", 113 LSA. That cam would be the ticket...!! But again, that's custom grind, as thus why I reckon order a custom grind.
The 276 is a nice cam but it runs out of puff at 4500. Its ok if he will drive on lower torque, but if he wants to rev, then it wont do. The 284 is a nice compromise especially with the added compression.

I want to be able to use it on the occasional track day now and then and i've learn't going full noise up a steep hill it just drops off when i want that extra bit, but the hard thing is I love how it's still driveable low down atm so i'll have to gather my thought's together enough to talk to crane and see what they come up with. Biggest problem is i can't know for sure what my actual CR is untill i pull the heads... but i dont wanna do that untill i'm actually doing the conversion, I do have a couple of std efi cams laying around... not keen on using one of those untill i sort out the cam i want.... kinda waste of time redoing the valley gaskets again + lifters + timing case cover gaskets.
I dont mind spending the extra as long as I'm not walking in and asking for a big stick that runs like crap!

 

[Aussiepride5L]

Yeah mate, for sure about the CR. At the moment you power curve is about from 1800 to 4500rpm...? If so, thats pretty much a 276. The 284 is from 2200 to 6000rpm. Thats not a huge difference. The VT roller came is a 278, 1000 to 5000rpm- probably the most usable grind out, but again for track...it might fall short a little. A 284 with a LSA of 13-14 will probably make the power from 18-2000 to 6000rpm. Pretty nice...!! Mind you, 10:1 CR, ported VN heads, powertorque dualplane highrise manifold, dynojetted rotty-quadrajet or 4brl injection, hardened pushrods, roller rockers, full exhaust, full MSD ignition to boot as well and it'll be a fkn ball tearer....!!! :-D :-D :-D

 

[ari666]

you power curve is about from 1800 to 4500rpm...?

The 284 is from 2200 to 6000rpm.

Thats not a huge difference.

lol .

 

[PaRaDoX]

Yeah mate, for sure about the CR. At the moment you power curve is about from 1800 to 4500rpm...? If so, thats pretty much a 276. The 284 is from 2200 to 6000rpm. Thats not a huge difference. The VT roller came is a 278, 1000 to 5000rpm- probably the most usable grind out, but again for track...it might fall short a little. A 284 with a LSA of 13-14 will probably make the power from 18-2000 to 6000rpm. Pretty nice...!! Mind you, 10:1 CR, ported VN heads, powertorque dualplane highrise manifold, dynojetted rotty-quadrajet or 4brl injection, hardened pushrods, roller rockers, full exhaust, full MSD ignition to boot as well and it'll be a fkn ball tearer....!!! :-D :-D :-D

are you on crack? When i had a 276 fitted to my car the powerband started at 3000rpm and ended round 5600rpm. (stock manifold, just tuned,exhaust and CAI)

Are we all speaking the same language? ie. Advertised duration?

The dual plane manifold has shorter runners pushing the power band up yet again.

My best 60' time was 2.2 before the cam and i could not get anything under 2.4 post cam, if the 276 was responsive from 1800rpm like you say that is what the torque convert locks up at and you'd see an lower 60' time.

 

[Immortality]

are you on crack? When i had a 276 fitted to my car the powerband started at 3000rpm and ended round 5600rpm. (stock manifold, just tuned,exhaust and CAI)

Are we all speaking the same language? ie. Advertised duration?

The dual plane manifold has shorter runners pushing the power band up yet again.

My best 60' time was 2.2 before the cam and i could not get anything under 2.4 post cam, if the 276 was responsive from 1800rpm like you say that is what the torque convert locks up at and you'd see an lower 60' time.

You hit the nail on the head with the first line. The stock manifold just won't make power to 6000rpm. A dual plane high rise TP manifold will breathe better then the standard manifold at high rpm and isn't to much of a slouch at low rpm either. Also upping the compression to 10:1 will get you back a fair bit of the low rpm torque.

Running a stock holden 304 with any decent kind of cam is just a huge compromise, especially when sticking with the standard banana's manifold.