FK series cams for 2017cc,need opinions,

[slingblade]

im slowly putting together one of my favorite configurations,78mm stroke with 90.5 bore,gene berg stock valve sized heads,hemi cut flowed,polished,H beam shorter than stock rods,ive also bought some tool steel lifters but need some input on a engle FK series cam,im leaning towards the 48 with 314 duration but wonder if bottom end performance will suffer?ive ordered the delorito upgrade kit for a set of 45 dels from CB to help some with this,whats the opinion of people here?
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you had better brace yourself for whats on the other side,,evel knevil

[Dan Ruddock]

Too much for a daily driver but if your building a race car/weekend warrior might be fine. I am not a fan of the FK4x series, too much noise. Also way too much cam for stock valve size heads. I would run a GB309.

Dan

[GTV]

The FK48 is way too much cam, sorry but that is a total bastard combination of parts.
The carbs are too big (or the heads are too small).
The size of the engine is also on the large side, valve sizes should be increased to feed it.
Hemi cut usually means low compression, which is also a terrible idea with a big cam.

What is the intended application?
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EMPI Power Rules!

[Alstrup]

The update kit is WAAAAAY overkill for such an engine. So is 45 Dells for that matter. You will need about 36 mm venturies to get them to run right.
What are you after since you are trying to make that somewhat, shall we say different set up ?
Such heads will peak in power somewhere between 130 & 145 hp depending on how good the ports really are. By 145 hp they need to be GOOD! and with lots of static compression, like 12-1 or so.
I´d say about an FK44, - maybe Fk45 and you can´t use more duration.

T

[jfats808]

Fk42 or 43 is probably the highest I'd do with that set up. I'm doubtful you'll get that much CR out of the build during mock up alone without flycutting that semi hemi chamber down. Aim more conservatively with 9.5.
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2276 IDA's 86C 11-1 DD

[slingblade]

ive run this combo before with good results,the heads were done by mike wooten at berg,and also had the short intakes matched and flowed together and they outflowed bigger valve heads with a webb 86a cam,good smooth idle and pulled good up to 7500 with the del 45s,no venturis,the one thing ive left out in the original post is i used gene berg stock length rods,ARP rod bolts/nuts,magnafluxed on the first motor,im going to use a slightly shorter rod,H beam eagles i picked up at a swap meet yrs ago,on the one we are discussing here,this will lower the compression slightly more which will lower head temps more, the goal is to run it on mid grade gas and this will only help meet that,the original motor wasnt a slug either,i had it in a 67 bug with whatever gear they came with and it ate cobra mustangs,V6 hondas in 2nd gear all day without running hot,with the cam change im looking for a 8200 rpm range where it just quits pulling,the webb quit around 7500rpm,the limit the berg rods were intended to be limited to,the upgrades im doing the the dels are to get rid of the hiccups just off idle,and help smooth up the transition from off idle to wide open,
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you had better brace yourself for whats on the other side,,evel knevil

[slingblade]

oh im putting the motor in a 69 bug body,412 gear,beefed up by rancho,the other motor i play around with is a 2332cc,berg crank,carrillo rods,041 heads,webb 86A cam,tool steel lifters by smith machine works,ive picked up a set of 48 IDAs opened up to 52mm by berg,profiled etc,etc,tried to run them but its obvious the heads need bigger valves and or venturis to speed the air up by the fuel circuits,these carbs are works of art,they should be mounted on the wall of a man cave,,
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you had better brace yourself for whats on the other side,,evel knevil

[slingblade]

[modok]

If the valve size is small compared the the displacement, a tighter lobe center is a good idea. fk-8 might be ok, if it was on 105 or 106 lc

[slingblade]

[bugguy1967]

Look at the cam's description, and really asses if your old combo was ideal: http://vwparts.aircooled.net/Web-Cam-Type-1-Camshaft-Grind-86A-1-4-or-1-5-p/00-082.htm

ANY engine can make a noticeable improvement in power over whatever you had before if you throw more ccs at it, but it doesn't mean the engine is running efficiently. The 86A makes power to 6000 RPM, therefore it PULLS to only 6000 RPM. People use the word "pulls" wrong. It's where the powerband falls off. A stock 1600 pulls to about 4100 RPM. If you swap it with dual carbs, it can rev higher, but STILL only pulls to 4100 RPM. The camshaft profile and headflow are the biggest factors in powerband.

So you had a 2007 with stock heads, and a cam combo that lifted WAAAY beyond the point where stock valves can still flow, weak compression, and carbs that didn't help the bottom end at all. I'd stake my life that you would have had a MUCH more powerful combo if you would have bumped your compression into the nines, got off Berg bandwagon and used a real set of big valve, small chamber medium ported heads, and matched your induction accordingly.

Remember that dyno shootout years back? Clyde was trying to prove a point with his 2276; he wanted to show that you could have a high horsepower, low compression, or "reliable" engine that could run on regular pump gas. The result? One of the lowest readouts of the competition. CB's winning 224 HP, 11.0:1+compression engine was tuned so well, it ran on 87 octane before the competition.

If you want to make actual power to 8000+RPM, you need to do away with what you think you know. It seems like you've overcarbed two engines already. You need to select component that will be flowing at their peak when you're engine is at its' upper RPM. On your other engines, the carbs were barely working at the top end. Here's what I'd do if I wanted a REAL 8000 RPM 2007:

78 Chevy journal crank wedgemated

5.4 H-Beam rods

Lightened Mahle or custom 90.5s with Total seal, or other type of low friction, high RPM rings

Tim's 42x37 Signature head or other similar head with titanium retainers, longer valves, and CB 650 springs

FK47 with true 1.4 rockers to keep lift down, aluminum dual taper pushrods, light lifters, Magnum gears

10.0:1 compression. The cam needs it. It will run cool if everything is done correctly. The torque will be noticeable sooner. Use real O.E. complete tins.

48 IDAs with 40mm vents to start or 48 IDFs.

1 3/4" header
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"A petrol engine can start readily, run smoothly and give every appearance of being in good order, without necessarily being in good tune." - Colin Campbell, "The Sportscar Engine"

[GTV]

[slingblade]

[slingblade]

oh,and i dialed in the webb 86 according to the cam card,it pulled to 7500,then you could feel it flatten out,time to go to the next gear,
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you had better brace yourself for whats on the other side,,evel knevil

[Bruce]

[Bruce]

[bugguy1967]

I'm sure he states what he states because of actual experience. I've heard of a best of 137 CFM with stock valves, myself. The heads had several, several hours of bench time and massaging. Stock ports in 040 castings with a seat blend can flow enough to make 100 alone.

Torben, when you post, I bring my note pad.
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"A petrol engine can start readily, run smoothly and give every appearance of being in good order, without necessarily being in good tune." - Colin Campbell, "The Sportscar Engine"

[bugguy1967]

Slingblade, the last combo to come off my stand was a 2276 with a V26 cam and 1.52 rockers, 10.0:1 static compression, .050"ish deck, 56cc chambers, 42x37 Mid D Brother's heads, 44 IDFs, and 1 5/8" header. When the engine goes back to the dyno, JayCee is confident in it's ability to make 160-170HP at 6500ish RPM. The engine runs on 91 octane all day, and I ran it in my garage with 87. No load on it here, but it ran just fine. Engines actually run cooler when their within the cam's target compression range. These big cams bleed off a lot of compression while running, so you need to compensate by raising the static compression.
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"A petrol engine can start readily, run smoothly and give every appearance of being in good order, without necessarily being in good tune." - Colin Campbell, "The Sportscar Engine"

[jfats808]

I forgot to mention that I'd run cb 1.3s with the fk42/43s. I personally feel not to build an engine to run past .500 lift and stock sized valves.
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2276 IDA's 86C 11-1 DD

[MURZI]

Just built a 2017.
Street eliminators. 42x37, 10:1, xr310 106LC, 1.4 pauters, 44 webers a1 low down exhaust. Beast!!! Easy driver and screams when you push the loud pedal. Quiet cam.
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62 vert
2276
Tim’s welded heads
45 Dells
A1 sidewinder
Fk44 cam