1327CC Build

So after a couple years of being told by many to get rid of my 1075cc and build a 1327CC, I have begun. Got most of the parts gathered, but im getting stuck on the head.

I have a J head already. But is that big enough even with porting and oversized valves? Possibly can lay my hands on a GPZ head

MK2 Cases
MK2 Crank welded
1-2 Auto Neutral on the Bottom Transmission
MTC Big Block
J or GPZ Head?
Webb #110 (.395 lift) Maybe too small?
Mikuni RS 36 Flat slides

Would love to hear everyones thoughts, opions or favorite combinations

I have a 1327cc drag engine and run .460"ex/.480"int cams. I have a Z1 head with 37/31 valves but the guy who ported it really knows his stuff so its opened up real good. I run a 34cc combustion chamber so compression is up there. My carbs are a bit over size, 40 Lectrons.

I have .420" lift cams in my 1200cc street engine so I would not go less than .435" for a drag bike.

I can't run/start the 1327 on less than C14 gas, so that blows ($$$)

Carbs are on the small side, 38's would have been better for 1327. J head is OK because you can go bigger on the valves than I did (mine super low $$) If you run a GPZ head then you can go 43/34 on the valves so you can run bigger carbs (40's min) and cams (+.500")

There may be other guys here that can chime in.

Hoping DragBike_Mike shares his thoughts on the subject

Injected,

May I ask what your ET and MPH are with that combination?

Southpaw wrote:

Injected,

May I ask what your ET and MPH are with that combination?





 

Nothing to report yet, have not been to the track with that bike.

Same bike with 1075cc setup ran 9.28@142MPH in quarter.

The guy who built the chassis originally had a 1327cc engine in it and ran 8.60's about 160MPH (injected alcohol) but no timing slips to back that up. I got that info from the guy who ports my heads as he knew that bike very well and did some engine work for the owner who has since passed away.

I was hoping to run conservative 9.20's at around 150MPH. I weigh about the same as the guy who ran the 1075 engine and I know I will be making more HP than that combination, but slightly less than when it had the alcohol setup. I figure slower ET's due to hand clutch manual shifting, and I don't really care as mine is just a T&T bike.

Potential performance will be based on total package weight, engine HP, and the gearing/tire/trans combination.

I have a 1327 cc with 465/435 sticks J head. Neutral down 5 up. I run 36 flatslides and they are fine. Head was done by Larry Cavanaugh (RIP) and he match ported manifolds to my carbs. I run a dyna 2000 with additional rev limiter. 10 1/2 to 1 compression but probably closer to 11 to 1. I run 110 octane and have never attempted lower octane with the dyna 2000 ( but have been told I could.) Never been down the track because I built it to ride on the street with friends. I have owned the bike for over 25 years and it has evolved from original cases 1000 to 1075 to 1170 to 1260. Kept the bike but sold the 1260 to put in another bike. The 1327 engine with new unmolested cases was built brand new. Great street engine but honestly doesnt come out on really hot high humidity days. For those days I have another stock KZ1000 ltd.

Southpaw wrote:

Hoping DragBike_Mike shares his thoughts on the subject

A little late to the party here, but here are my thoughts, FWIW.  
You're going to bracket race this motor, correct?  If so, consistency is the key.  A motor with a broad flexible powerband will take you round after round.  I know that everybody wants to go fast, I get it.  However, I'd lean towards smaller valves & ports, low(er) lift cams, and smaller carbs for a killer bracket bike.  The key is to have a balanced and matched combination.  With milder, shorter duration cams, you don't need sky high domed pistons for an effective (vs static) compression ratio.  A mild, low RPM, engine combo won't make the big HP numbers, but it will be more reliable and consistent.  

As a point of reference, I've included a pic of the small tire bike that I ran before the turbo bike in my avatar.  1327cc, 10.25 to 1 pistons, stock-size stainless valves, MkII head with mild porting to match the .380 lift Megacycle cams, and 33mm Mikuni smoothbores.  The bike would reliably run mid-9's all day long (my race weight was approx 185lb back then).  I'd also run it in Super Gas (9.90 index) at the Prostar races with a little detuning.  

So, to answer your original question, Southpaw, I'd say that your J-head with mild porting would suit your needs.  And, I'd have no problem running those "mild" .395" lift cams.  Use some of the $$$$ saved and buy some shim under buckets for those cams, if you don't have them already, for added reliability.  Again, just my opinion.   Take it for what it's worth.

Thanks and good luck with your project.

Mike

 

The one common thing I have seen at the track with serious bracket racing contenders is there between runs setup. A shade awning, and big multiple cooling fans (generator) are what I see off of every trailer on winning efforts. This equipment and preparation has little to do with the on track performance but is of equal importance.

Like I said once before most serious contenders are running Lectrons because there is no jetting to mess with once setup properly. They self adjust for temperature and humidity changes so the only thing you may have to tinker with is the lockup based on track prep. Those carbs are more important that whatever the engine displaces according to racers I have talked with. 

Injected wrote:

 A shade awning, and big multiple cooling fans (generator) are what I see off of every trailer on winning efforts. This equipment and preparation has little to do with the on track performance but is of equal importance.



 

Yes, 100% agree, Injected.  Racing "to win" is more than just making passes downtrack.  There's a whole lot of other things going on in the background that have to be done repeatedly right to maintain consistency in the process.  You want to minimize distractions which will affect your focus and performance.  The teams that are winning consistently from week to week have their operations buttoned up pretty tight - guaranteed..

Mike