Printable Version of Topic

Click here to view this topic in its original format

914World.com _ 914World Garage _ What camshaft?

Posted by: DrifterJay Nov 28 2004, 12:34 PM

Ok....thinking of cracking the case on the race engine with bad cam...kind of father son project...Any advice on what cam...Hi revving, low displacement, high compression motor...48x38 valves...dual valve springs, 96mm pistons.....Euro, 1.8 length (66m?) crank. What cam should I go with if we go through with it? I am running Dellortos 40 drla carbs, set up for a "big" 2ltr, with the cb performance linkage. I am thinking of going webcam 86b? Any other suggestions?

Posted by: Jake Raby Nov 28 2004, 12:43 PM

Hmmn,
with that huge intake charge, and the exhaust port challenges you will need alot of split in duration to make any power, and get it to tune. A straight pattern cam on a TIV only works well with a 75-80% margined set of heads, with those valves and typical porting I doubt you are at 65%, so leave the straight patterns like the 86B alone..

what rev range are you looking for and I'll try to help.. where do you want your power concentrated?

Also, what are your heads rated for lift wise? the 86B is a lift healthy cam that can compromise springs easily if not set up bindless.

Posted by: URY914 Nov 28 2004, 01:00 PM

One question leads to about 10 others...

Paul

Posted by: Jake Raby Nov 28 2004, 01:03 PM

If its to be answered correctly and completely.

Posted by: DrifterJay Nov 28 2004, 02:06 PM

I want a powerband of max power from 4k-7k...preferably with a modest amount of power above 2500k. I am not sure on the lift. I know I have dual, hi rev, valve springs with titanium retainers. They are currently clearanced for 96mm pistons (94 same...) I am looking for a hi rev engine for autox. I already have the heads, and I will use them for something, so what will work. If I make 120hp, I will be happy. I know a lot more is obtainable, but i would like to drive without spending too much.

Posted by: Aaron Cox Nov 28 2004, 02:11 PM

does that mean he needs a cam with lots of exhaust lift/duration to utilize those heads?

Posted by: DrifterJay Nov 28 2004, 03:47 PM

bump

Posted by: DrifterJay Nov 28 2004, 04:53 PM

bUMP Anyobody?

Posted by: DrifterJay Nov 28 2004, 05:10 PM

HELLO!

Posted by: nebreitling Nov 28 2004, 05:15 PM

try elgin cams

google 'em they have a website with a catalog of grinds for 914s

been at it for a long time, they must know a few things...

n

Posted by: skline Nov 28 2004, 05:16 PM

You gonna build a race engine? For race only?? If so, look into an 86c web cam. Go with your straight cut gears and then put it all together and race it. That doesnt mean drive it to every track event, that means get it dialed in and trailer it to the tracks.

Posted by: Brett W Nov 28 2004, 08:46 PM

I would look at something like a 163/86b or a 163/86C. I might even be tempted to run something like an 86a/86a+10 maybe 15. Run it on a 104. You may have to deal with valve clearence issues though. You won't be able to get a whole bunch of compression out of the flat top 96mm pistons. What ever you do make sure you get a set of ceramic lifters. You could make 120 but it will take a good exhaust system and good cam selection. I would go a head and step up to a 2.0 crank or maybe even a 78 for the extra grunt.

Posted by: Jake Raby Nov 29 2004, 09:16 AM

163/86B+2.5

Run it at 9.5-10:1

Posted by: GBallantine Nov 30 2004, 07:43 AM

OK, What type of Webcam would be suitable for 2270 motor? 2.0 litre heads ported and polished 44 and 38 valves with JE 96mm pistons/78mm crank/Weber IDF 44 with 9.5.1 compression, used as a Driver Ed track car, no street use. According to Webcam the 86B is suitable for small displacement race motors. Is a 2270 considered small? Or would the 86C be a better choice. No listing for a 163/86B + 2.5.

GB

Posted by: Brett W Nov 30 2004, 10:34 AM

What do your heads flow? Where do they stop flowing? What are you using for an exhaust system? What kind of rpms are you turning? What kind of springs and retainers? What gearing in your tranny? What kind of Dizzy?
You need more compression. I would pass on the 86A too small for most cases. What are you running now? The 163/86b+2.5 is custom grind. It would work pretty well although I might run it at +5 for your motor.

Posted by: Jake Raby Nov 30 2004, 11:41 AM

Its impossible to answer a cam question without knowledge on the heads...

I knew drifter jay had those huge intake valves, and that 163/86B+2.5 has really helped me make those heads work in the past..

There is about to be 30 new Web Cams available- But not through web themselves!

Have your heads flowed- It's priceless information for configuration.

Posted by: crash914 Nov 30 2004, 03:18 PM

Just to add to the confusion....I am now running the 163/86b...this thing has a lot of low down torque....it is on a 2.7 big 4 though...

I am still dialing this in, but listen to Jake...he talked me out of using a 86b/86c and I am glad he did...now anyone want one?????