4k Cams. Any Cuts Better Than Others?

[altezzaclub]

I'm assembling the stuff I need to fit twin inch & 1/4 SUs, 4-2-1 extractors and a cam to the KE70. Seeing its road use only (maybe the odd gymkhana..) I'm happy with 1" & 1/4 carbs, and also we live at 2500ft at Orange.

 

For those of you who can't appreciate the difference a couple of thousand feet makes, the KE runs fine with the ignition settings we have at home, but pinks as soon as we go down to Sydney.

 

With cams that means lift is important over overlap. To successfully rally at Jo'burg (6000ft up) and Cape Town (sea level) means a change of cam and carbs each time. Jo'burg also doesn't offer the same high-octane fuel that Cape Town does.

 

I'll get the followers re-surfaced, but don't intend to lift the head so stock compression and valve springs.

 

I've sorted a list of cams from the net, bolded the most likely ones for what I need, and was wondering if you had any comments about which company had good or bad work, or cheap or expensive.

 

I can start with Tighe, having sent them 3 emails over as many weeks asking them to suggest a cam, and received no replies! Some companies will not survive the digital age!

Edited November 2, 2009 by altezzaclub

[KE55PIG]

Crow 740 master

Duration: 280/286 (in/ex)> Timing in: 32/68 (seat to seat)> Timing ex: 73/33 (seat to seat)> lift at valve: .401/.401 (thou in/ex)

[Felix]

I'm pretty sure he is building for max torque and to have peak HP around 6 grand.

 

A 280+ degs (advertised) duration cam will be making max HP at around 8 grand or just over in a 4k. Plus it'll need 10.5:1 CR which if you read his post you'd see he is trying to get the maximum from the stock CR.

 

I'd be looking at up to 260 degs (advertised) duration max, with the maximum lift you can get.

 

I've dealt with Tighes before, but was localish so I could just go straight in. Maybe try ringing them? I've used the one cam in a couple of street driven motors for 7-8 years with no problems. That is a Tighe 113, when I ran it on my old dished 4k, it made best power between 3000-7500 in my setup with a ported head 9.9:1 CR, DCD weber and 4-1 extractors.

 

When I put that 4k in the ke16 for the missus, I fitted a Camshaft Engineering CE778 cam in it. It has the same specs as a 3k-b cam (256 degs adv duration) with a heap more lift (423 thou). Man did that cam pick up the low to mid, but peaked at 6500. ie. pushed the powerband down 1000 rpm across the scale.

Edited November 2, 2009 by Felix

[KE55PIG]

i was just thinking he should put all the cam grinds that everyone knows of then can go in the faqs

[altezzaclub]

KE55 I'm happy to do that, I'll dredge up cam grinds from these through to road-race like you fitted.

 

However, it seems like Crow don't cut K cams any more, its all twin-cam stuff on here-

 

http://www.crowcams.com.au/search.aspx

 

The comments on where a cam really works and if it needed new valve springs/compression will help if people want to use it as a reference.

 

Thanks Felix, as you can see my Tighe option was a 113, but from your post its probably a bit hot for what I'm doing. Currently I'm planning the Waggott 233, as although it has similar durations it opens really quickly, as you can see from the 50thou readings.

 

Cheers

[KE55PIG]

yes but u can email crow that what i did think they have there old info on there systems still.

Would be good To have a database of what pepople have used .

[Felix]

No worries.

 

Thought you might be interested in a few screen grabs I just made from Dyno2000. Please note, take 10-15% from the HP numbers for more believable real world results, the software is used more for comparative rather than outright numbers.

 

The motor is a 4k modelled with 9.0:1 cr, stock sized small ports, and small tube extractors with mufflers (stock 4k has stock manifolds and mufflers), airflow is as for a downdraft weber (except stock 4k) as it is fiddly modelling SU's.

 

 

Took out the 113 and threw in a stock 4k for comparison.

 

[KE55PIG]

felix can u do that with my cams specs above and a 10.5.1 compression and some how around same cfm as twin 3k carbs

[Felix]

felix can u do that with my cams specs above and a 10.5.1 compression and some how around same cfm as twin 3k carbs

 

I can do that, but you need to give me a better description of the planned mods.

 

5k? If so any overbore? What head (3/4ksmallport, 5k, 3kbigport)? Porting/headwork? 4-2-1 or 4-1 extractors? etc.

 

The software is sort of basic in some ways, but there is a massive amount of possible combinations.

[camerondownunder88]

Tighe in Brisbane I have had no issues with and they helped me HEAPS witha cam once before and he does a lot of work and is pretty old school so I don't think internets is his thing..LOL

 

But He will do anything you ask for really. I wanted some of his grinds in hydro setup in a 5K once before so he did (hrdyo have different ramp rates etc to normal cams etc) As all his are for solid lifters. Well he ground it for hydro and workds great :(

 

So there good but I think phone is best way to get him. And you tell him what you want he will also grind it to that so don't also just go by what is on his site as same price he will grind anything for a K motor. So if you want more duration etc jsut ask.

 

Cheers

Cameron

[altezzaclub]

I've give Tighe a bell tomorrow in that case Cameron-

 

Felix, where was that 3K-B from?? It might have a bit much lift for stock valve springs (did you use something special with it??) but the curve looks like what I'm after!

 

This address for Camshaft Engineering returns a "Bad Address" error...

 

Engine Reconditioning Osborne Park WA: www.camshafteng.com.au

[KE55PIG]

can u do 2 plz

one a 4k with extracctors with my cam twin 3k carbs 32ml inlet ports. 10.5.1 (going in by christmas)

5k 32 ml ports eg bp twin carbs and my cam with extractors 10.5.1 (Hopefully march)

 

4-1 extractors

 

u can play a bit with lil higer compression if ud like that would be good cheers

Edited November 2, 2009 by KE55PIG

[Felix]

altezzaclub the Camshaft Engineering cam was in a 5k bottom end I bought. It was actually a hydraulic grind but seemed to run fine with solids. Anyway that is besides the point you could get any decent cam grinder to grind to whatever specs you wanted in a solid grind. And yes I ran the standard dished 4k valve springs, which are I think the same as 5k ones, no coil bind. The specs:

 

CE778: 22/54 62/14 (ground 4 degrees advanced) 256 degs (adv) duration, 423 thou lift at valve.

 

 

KE55PIG I made some runs with 10.5:1 CR and a bigport head. I think the cfm ratings I used are optimistic for the twin aisans as I found a DCD weber (used its CFM ratings) to go harder in the top end. I threw in a run from my current 5k with a ported medium port (5k) head and a 270 degs tighe 113 and 9.6:1 CR for comparison. Also chucked in a totally (everything) stock 4k as the benchmark.

 

Remember take 10-15% to get an idea of what flywheel HP is achievable with a perfect tune. Program assumes perfect A/F ratios and timing curves.

 

Edited November 2, 2009 by Felix

[KE55PIG]

i don't no what one is what lol sorry

And i havent seen any cfm rating of these carbs my guess is they would flow around 150 % of a normall 4k carb as they only lose 2 ml of the troats but are much larger ports in the actual manifold helping the cfm

Edited November 2, 2009 by KE55PIG

[Felix]

Look at the legend down the bottom.

 

ke55pig5k is your theoretical 5k. straight lines

ke55pig4k is your theoretical 4k. diamonds on the lines.

5know is my 5k. squares

4kstd is a stock 4k. lol. triangles

 

I took the screen grab off my main computer which has a big monitor and 1920x1200 resolution so the symbols are a bit small. Maybe zoom in a bit to work out which line is which to start with then you'll get it. The graphs get busy with a few runs on there together, but are meaningless by themselves with nothing to compare them to.