Mild 7K-C Cam Profiles

[KE25 Nut]

G'day

I'm currently in the middle of doing a 7k engine conversion into my ke25. I know it's a big improvement on power compared to the standard 3k but I'm looking to get abit more power in the mid rpm range.

What cam profiles should I be looking for?

Lift, duration, advance etc.

Or does anyone know at least what they are standard to give me a base to work from?

The engine is set up with twin 40mm webers, extractors with a 2" exhaust slightly ported head & manifolds and heavy duty valve springs. I'm also keeping the hydrolic lifters as i have heard mixed stories with converting to solids, will this be an issue with a mild cam?

Any help is greatly appreciated as I'm getting sick of google searches!!!

 

Cheers

[Mechanical Sympathy]

I'm interested in putting one of these into my KE55 XX also so I'd be keen to hear how yours goes. Although I'm looking to use twin Aisans on a Sprinter manifold.

 

While no expert on the matter I understand that being an undersquare engine, lift is more important than duration. I'll be considering something around 25-65 270 degrees duration, 0.398" lift.

 

I'll look to skim the head for around 9.5 to 9.8:1 compression, port it with larger valves if possible and lighten the flywheel to give it a herby idle.

[coln72]

Don't stress about the hydrolics. Ran a 5k up to 8000rpm without issues with a reground cam. From memory it was a Wade 169 grind.

 

[philbey]

this is like a duet. The philb coln duet. Phil collins duet??

 

I also run hydro, it's big, it's aggressive and I didn't muck around with lame duck compression like 9.8:1. I went 11.5:1, loads of lift and overlap.

 

And I never have to gap tappets. Ever.

[coln72]

We just have to convert the non believers ;)

[KEI069]

We just have to convert the non believers ;)

No converting needed here, I've had 3 5ks and all have been left hydro.

My current one still making power @ 6500 rpm

[tojo2]

Tell camgrinders your plans, what you got and what you want. They got heaps of experience. ;)

[coln72]

What tojo2 said, but be honest with them.

[PHATKE20S]

I'm with you guys on the hydro lifters. Ive had a few 5Ks & they were all happy to rev out without any issues

[KE25 Nut]

Thanks for the input.

I'm glad to hear I've done okay by keeping the hydronic lifters.

I guess I'll just head to a cam grinder and just let him know what I got a what I want.

Another question I I'm curious about is what starter motor should I run.

I've read a few people running re-geared 5k starters what are the advantages using this over a 4k or 7k starter.

Planning of just using a 4k flywheel and clutch setup.

[coln72]

some 5k starters are physically smaller allowing more space for exhausts and they can be removed without dropping the exhaust.

[tojo2]

7k starters are geared , even smaller than 5k ones, and from what Ive read the only ones that will fit a 7K

[Taz_Rx]

7k starters are geared , even smaller than 5k ones, and from what Ive read the only ones that will fit a 7K

 

Nope, I've used a normal 4k starter as well as my 5k reduction starter with my 7k.

 

Iirc camtech have hydro listing on there online catalogue for 5k's...which can also be used for a 7k.

[KE25 Nut]

So ideally should I be using a 5k starter or a 7k starter? I'm after whatever would be most reliable as this car is my daily.

And are there any difference in the diameter or the number of teeth on the pinion gear?

Cheers

 

[philbey]

Use whatever you can get your hands on. I switched to a 5K reduction gear starter simply because my old one died and a mate had one spare. Otherwise, I've used the old 3K ones and the later 4K ones as well. I have a lot of compression and the 5K reduction gear seems to be the best, but they're harder to find.

 

There wont be any difference in pinion gear, but the reduction units have a compact gearbox between the motor and pinion, which allows much greater starting torque with a smaller motor.

Edited July 17, 2013 by philbey