25-65 Cam In A 5K?

[5ksev]

hey, i keep getting mixed feedback on this cam, its the tighe 104.. 25-65 270dur with .423 lift

 

will it be to big for a 5k wich is 50/50 street highway driving..

 

what will it be like in low rpm?

 

thanks

[snot35]

While I have never actually tried that combination, I'd say that's a fairly mild cam and should actually work pretty well with a 5K. Couple it with port work and it should make for a fun modification.

[altezzaclub]

The Girl's KE70 runs great with Crow's 270deg 0.4lift grind. Grumpy idle but pulls straight off from low down, and its smooth with no hesitation anywhere.

 

Up around the 280deg gives s poor bottom end doesn't it?

[5ksev]

I don't want lumpy idle, due to being on my P's..

 

And also, it apparently peaks at 7500rpm..

 

I don't really want to be revving that hard, as Its not balanced..

 

Will it be to big for street driving? Or should I give it a go?

[TRD ke70]

Depends on a lot of other things, like what carby do you have, what exhaust are you going to use.

 

25-65 is quite a small cam and if tuned right, you shouldn't notice it.

Reversion of exhaust gases is the biggest problem, this will really make your cam lumpy at idle.

get this right and you'd be surprised how bigger cam you can go before it become lumpy at idle.

 

We had a 40/78 with 300 duration in the rally car and it idled like mums shopping trolley!!

[Evan G]

mr altezza whats the duration at 50 thou? 270? and lift at tdc 413?

 

i think we got the same cam.

[5ksev]

Depends on a lot of other things, like what carby do you have, what exhaust are you going to use.

 

25-65 is quite a small cam and if tuned right, you shouldn't notice it.

Reversion of exhaust gases is the biggest problem, this will really make your cam lumpy at idle.

get this right and you'd be surprised how bigger cam you can go before it become lumpy at idle.

 

We had a 40/78 with 300 duration in the rally car and it idled like mums shopping trolley!!

 

well I'm running 10:1 compression

2 1/4" exhaust with 4-1 extractors

and a weber carby, pretty sure its that dvg or what ever

[TRD ke70]

Have a look at this!!

 

This is what i mean by reversion, make your extractor flanges/ holes bigger than the heads ports, this will create an anit-reversion lip.

You'll need it if your running a 2 1/2" exhaust.

 

How To Modify Ford SOHC Engines - David Vizard.pdf

[5ksev]

Have a look at this!!

 

This is what i mean by reversion, make your extractor flanges/ holes bigger than the heads ports, this will create an anit-reversion lip.

You'll need it if your running a 2 1/2" exhaust.

 

How To Modify Ford SOHC Engines - David Vizard.pdf

i think i understand it.. ill just chuck the cam in for now, then slowly do the other things

[GJM85]

The 104 doesn't have a lumpy idle.

[Medicine_Man]

I have the 104 in my yellow KE70 with 4K, Extractors, DHLA40s etc.

 

Can confirm no lumpy idle..

 

Used to pull hard when the motor had compression, lol..

[altezzaclub]

Evan its the Crow 606 that Slo-030 has, 270deg advertised, 224 at 50thou (opens fast) and 0.397 lift.

 

Its on twin inch & 1/4 SUs, 9.7 to 1 compression & 2" extractors into inch & 3/4 exhaust.

 

The SU carbs might be prone to lumpy idle as the floating pistons will jump up and down with the engine tilting. I can see a pothole in a smooth road on the fuel mixture display as the floats drop then rise.

[5ksev]

I have the 104 in my yellow KE70 with 4K, Extractors, DHLA40s etc.

 

Can confirm no lumpy idle..

 

Used to pull hard when the motor had compression, lol..

okay good, i just don't want it to be

 

" oh hello mr police man, please pull me over! "

 

with the 104, how was it to drive around the streets at low rpm?

 

being in a 5k, it should come on cam a little earlier then in the 4k, am i right?

[altezzaclub]

being in a 5k, it should come on cam a little earlier then in the 4k, am i right?

 

In theory no, but it will feel like it does from the extra 200cc of torque. I'd expect the power curve to be the same shape but moved higher all over.

[Evan G]

mate, cops only pull over old cars if your driving like a MORON or do something stupid!

 

if your car looks respectable they wont give a rats ass!