Big Cam Problems

[chappo12]

hay guys

i just got my cam grinded at crow cams ($110) its a 608 grind

the car has been tunned and its got full electric ign but it drives so shit down low

i don't wanna rev the tits off all the time

 

i don't know what is causing the problem i can only think that the grind is to big

 

if so what can i do to give it more power and drivabilty down low

 

should i just make it pick up revs quicker

 

if so how do i do that

 

sorry about the spelling and gramer

 

i didnt go to collage thats my excuse

whats yours ?

 

 

steve

[godlovesugly]

my excuse is that I'm missing a chromosome. not sure which one yet though.

 

what engine are we talking about??

[snot35]

That grind is a big cam, with a lot of lift.

 

Basically you've modified the characteristics so that you'll have to rev it all the time.

 

You'd want to run quite high compression with that cam. You'd also want a very good port job, and probably twin carbs or quite a good EFI setup.

 

That cam is really too big for a street car, it's probably more of a tarmac rally sort of cam.

 

If you want something drive-able, I'd say you want the 621, or 609 TOPS. If you go the 609, you'd still want a pretty well tuned car so it will drive OK. I'd say it's probably a little too much, especially if it's a daily driver.

 

I think you'll have trouble fixing your problems with this cam.

 

It really depends on what you've done so far to the motor.

[Taz_Rx]

Mate you can't have your cake and eat it too!! :P

 

I have a 609 in one of my cars and even that is verging on too big for a regularly streeted car. Saying that, get it out at a motorkhana or in a paddock etc and its a completely different car.

 

 

If you look back through some older threads with headings like "what mods should I do?", "how do i get more power?" etc I bet every one has somebody asking the question - What do you want to use the car for? There is a bloody good reason for this.

No offence mate, but its seems you never asked yourself this question and now you're suffering from your poor decisions!!! :D

[Felix]

608: Rough idle, strong upper mid range and top end, modified engines only. Min 10.5:1 comp ratio. RPM RANGE 3500-7500 38-72/75-40 290°/295° duration 453 thou lift

 

:D no wonder it has no low end. The price you pay for a lumpy idle.

 

The best fix would be a milder cam.

Edited February 19, 2009 by Felix

[styler]

that cam is for fast street or race really....

 

also remember an engine is a balanced system,

so i would imagine:

 

To make it work:

290 deg cam

new harder valve springs to suit

11:1 static comp

 

To make it work well:

induction twin carb

exhaust extractors

more powerful ignition

ported head

bigger valves if possible

lighter flywheel

 

To keep it together:

balanced bottom end

make sure valve train is strong

 

To go the full show:

forged pistons

aftermarket rods

professional port

 

something like that anyway... you can't just get a hot cam only for use in a standard engine :D

[Felix]

you forgot to mention... Gearing.

 

To keep it in its' powerband:

Diff ratio. ie if you have a 4.1 diff, fit a 4.3 or smaller diameter tyres.

Close ratio gearset for gearbox. The revs don't drop so much between gears, motor doesn't fall off cam. Sadly these are not freely or cheaply available.

[styler]

haha knew i forgot something!

 

yeah some aftermarket gear sets are around $2500!

[chappo12]

yea lol

well its got extractors

weber 32/36

electirc ign

 

 

but i told crow cams that i wanted hot street performace and they said ok this is what you need

 

its not a daily driver

 

but its so lumpy sounds like a 12a

 

so if i get higher compression

and valve work down it should be better ?

 

any thing else ill try get pics

[chappo12]

4k motor by the way ke55

[chappo12]

how much does it cost for a head job LOL

and where abouts do i take it

[orangeLJ]

Depends where you live as to who you can get to do head work!

 

everyone covered pretty much everything,

 

but the more the merrier-

 

with 11:1 comp, you would have to watch which fuels you are using, and have your cooling system up to scratch.

 

we run 13:1 in the street stocker engine, and it only runs nice on aC10 blend that we buy directly from BP (and its not cheap!) anything else and it just pings its head off and runs like crap.

 

running 10:1 in my weekender (wont mention torana, it seems to get people upset) and it is fine aslong as I'm pumping in fresh 98 octane and nothing else, I've been caught out in places where they only had normal unleaded (93 octane these days I think) and it was a shit to drive, ran like crap (my timing doesnt help, but thats another story)

 

Is the motor stock apart from the camshaft, extractors, ignition and carby then?

 

Id say you would be better off buying a new billet in a smaller size, putting that in your engine, and starting another build with the 608grind and spend time and money getting it up to par. (ie. like the others have said, big valves, big ports on the head, head/block decked forged internals etc etc)

[chappo12]

thanks heaps

yea i live in canberra

 

will i have to do the bottom end if i give it more compression

 

can i ran high octane from the pump and add that nulon pro strenght octane boster thats ment to stop pining

 

I'm not to worryed about the cost of the fuel

 

i only plan to drive it every 2nd sat night

 

yea thats it only camshaft, extractors, ignition and carby

 

oh I'm putting a big radiator in it as well

 

its not my daily drive in fact i don't rego it in summer unless i need to go for a curise

 

torana thats f@$king sick

jealous

 

11.1 is high thats a fair bit of work i guess

were do you guys get your head work done

[Taz_Rx]

how much does it cost for a head job LOL

 

:D :P

 

Depends if you're paying by the hour or go to the right part of town and you might get one for half a pack of ciggies.

If you're married - Anything with diamonds in it!! :yes:

Edited February 20, 2009 by Taz_Rx

[chappo12]

lol

 

 

 

the local place said i was better of putting a 3k head for mor comp

 

 

if i bore it out would that help

 

also does a 4age bolt right up in a ke55

 

 

just need a quick answer