csa Posted June 21, 2007 Share Posted June 21, 2007 I'm thinking of doing a little work on my stock head (keeping the shortblock stock) The car is a T67, 1000cc manual I'd like to make around 8K save rpm, and I'm trying to tie togheter a shopping list. So far i contains: HKS 256/264 cams HKS camgeas HKS cambelt Crower springs & retainers (1.325" @ 85 lbs / Open: 0.980" @ 170 lbs / Coil Bind: 0.860") ARP top bolts porting and flowing of the top and for the questions, should I also get crower valves and HKS headgasket and if so, what thickness? Am I missing something here? Quote Link to comment Share on other sites More sharing options...
RobSheffield Posted June 21, 2007 Share Posted June 21, 2007 Why do you want to get HKS camgears? IIRC Crower titanium valvespring retainers would help Quote Link to comment Share on other sites More sharing options...
csa Posted June 21, 2007 Author Share Posted June 21, 2007 call it styling ;-) Quote Link to comment Share on other sites More sharing options...
RobSheffield Posted June 21, 2007 Share Posted June 21, 2007 Ahhh you want a stylish 8k rpm engine? Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted June 21, 2007 Share Posted June 21, 2007 You need an 8000 RPM capable bottom end for an 8000 RPM capable top end Unless you know EXACTLY what you are doing ALWAYS get valve springs from the cam maker. You don't need any trick titanium stuff, 8k is nothing to a modern DOHC valve train, you do need the right duration to allow it to breath at 8K, and 264's are pretty tame. You also need a turb(s) that have big enough exhaust housings to allow useful power up there. Your main concern should be the bottom end though. Quote Link to comment Share on other sites More sharing options...
csa Posted June 21, 2007 Author Share Posted June 21, 2007 okay...lets say I'm not willing to touch my shortblock, I only want to work on my top, with my existing T67 A/R 0.70 turbo. The 8K prm is not an ultimate goal, but I would like to rev a little more than stock. But I realy dont want to just move my "power band" up the rev scale...thats why I though of the 256/264 setup my self. But what would you recommend? Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted June 21, 2007 Share Posted June 21, 2007 The ports are great, as stock, probably better than a stock RB26 head. Porting won't be needed for those cams, unless you like spending dosh I'd run 264 inlet, 264 exhaust cams at the makers timing figures. I don't consider the stock bottom end good for more than a 7000 RPM limit, so new stock springs should be OK. Quote Link to comment Share on other sites More sharing options...
Digsy Posted June 21, 2007 Share Posted June 21, 2007 Chris (or anyone), do you know what the 2JZ valvegear weighs? Valve, spring, tappet and shim? Quote Link to comment Share on other sites More sharing options...
csa Posted June 21, 2007 Author Share Posted June 21, 2007 okay, I better forget about more rpm then my current "stock setup" makes full boost around 4300rpm, how will that change with 264 cams? Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted June 21, 2007 Share Posted June 21, 2007 okay, I better forget about more rpm then my current "stock setup" makes full boost around 4300rpm, how will that change with 264 cams? It'll go higher.... Dunno exactly HOW much higher, probably around 4750 `ish RPM. Depends on turbo back pressure, blah blah. Only way is put all the parameters in decent engine software (which you won't know or be able to measure unless you are Ricardo, so it's a bit pointless), or try it and see Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted June 21, 2007 Share Posted June 21, 2007 Chris (or anyone), do you know what the 2JZ valvegear weighs? Valve, spring, tappet and shim? I'll weigh an inlet set up for yoy later. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted June 21, 2007 Share Posted June 21, 2007 Chris (or anyone), do you know what the 2JZ valvegear weighs? Valve, spring, tappet and shim? I'll weigh an inlet side set up for you later. Quote Link to comment Share on other sites More sharing options...
csa Posted June 21, 2007 Author Share Posted June 21, 2007 hmm...it's really a hard decission wheter to do this or not...I mean...If I can't raise my rev limiter, I will only get a more narrow powerband out of it...and ofcourse a bit more power hmm....what to do Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted June 21, 2007 Share Posted June 21, 2007 I think a pair of cams will make a worthwhile power hike without moving the power band too high. Hell, I raced F3 for donkeys years, and I had a 1000 RPM power band, you'll still have plenty to play with. I know people rev the stock bottom end above 7K, but it's a long stroke, floppy old crank, and the stock rods and bolts will be marginal if you use more than 7000, IMO. Quote Link to comment Share on other sites More sharing options...
csa Posted June 21, 2007 Author Share Posted June 21, 2007 okay, point taken. So a shopping list could be as follows: Crower 264/264 cams Crower springs and retainers (not the trick titanium ones) Camgears (or can I use stock) HKS timing belt (or will a new stock do fine?) ARP top bolts (or will new stock be fine) new stock headgasket the cam spec are as follows: Duration: BC 264, Intake / Exhaust Duration @ .050: 222°/222° Lift (inches): 375"/.375" Lift (mm): 9.52/9.52 or would I be better off with som HKS cams or other? Quote Link to comment Share on other sites More sharing options...
Digsy Posted June 21, 2007 Share Posted June 21, 2007 I'll weigh an inlet side set up for you later. Terrific Thing is that's the first time I've ever seen the spring rate for an aftermarket valve spring quoted, so I should be able to work out what the spring cover for those cams is. Oh - spring fitted length would be handy, too. Quote Link to comment Share on other sites More sharing options...
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