150cc T-rex Daytona motor - photos

[Peter1230]

The daytona is light years better than the z155 and yx junk.

Grow a dick.

 

[grnman]

Come on mate we are all freinds here. if you dont agree with something, there are better ways to express it than that.

 

[exquisit]

since this engine has been out for a while i'll ask these questions

does the daytona 150 run a full skirted/long skirted piston?
how long between rebuild?

thanks

 

[themountain]

since this engine has been out for a while i'll ask these questions

does the daytona 150 run a full skirted/long skirted piston?
how long between rebuild?

thanks

1. YES
2. depends on the maintanance you give thae engine

 

[corey58]

@-2. well I know people that put well over 40hours on it and hasn't rebuild them yet, just oil changers often and new filters

tho i would rebuild it once a year to keep it at it peak,

 

[HACKMUNCH]

well we put ALOT of time on the "170" kit in the last week. we tried it with the upgrade 268 cam from daytona and the z40. with the 268 the engine revs into the 12k rpm range but sufford a tad on the bottom, with only 12:1 compression on the "170" kit i think that is where the problem lies in the weak bottomend, that along with the huge duration and overlap of the 268 cam. the bike kicked so easy with the 268 cam i though i broke something lol. would be an absolute ripper on the asphalt. since we race in the dirt we chose to try the z40 cam. with the z40 it make a huge broad power range and alot of torque, only reving out to about 10k but makes a huge midrange hit. with the z40 the daytona kicks ALOT harder. we had a huge indoor race over the weekend so we opted for the "170" z 40 setup. sam holeshoted heat 1 and ended up finishing 2nd in the main in the 12" pro/open class. there were a ton of fast kids and fast built klx bikes. once the videos get edited i will post them up for you guys. just for a reference in heat one the guy next to sam on the gate had a klx 178+r engine and they were dead even down the long start straight. not bad for a $200 retail total upgrade (z40 cam and 170 kit). other than the cam and kit everything else is bone stock on the whole engine no porting no nothing. hope this helps a few proud daytona engine owners.

 

[grnman]

Good stuff HACKMUNCH!

when you say the problem in the bottom end is to do with the 12:1 compression (and cam). do you mean the compression is to hight or low?

So i imagine your talking about the 2v '170'.
Was the install as simple as i imagine it would be?
Just like doing a rebuild?
Are you still running the daytona head?
pretty cheap way to add some power to the daytona.

So next step, how do you think the 4v is going to go with the yx 60mm 4v piston?

Look forward to the vids.

 

[wogtaz ryder]

Having another read through this and a few other threads , and seems everyone thinks the Daytona and Lifan run the same Stroke/Bore?

Did some quick searching and got this .. do these look right?

Bore/Stroke
Lifan: 56.5 x 59mm
Daytona: 57mm x 58.7mm.

 

[corey58]

yess that is correct,

Daytona is releasing 160cc stoker kits for them very soon

one each for the motovert and the LXR not looking keen to fully split both motors tho!
thinking about slipping on the 160tb kit and having my LXR a 177 why i got it apart, what the hell i say.

But gotta keep the tar an 160cc for the class CC's at the club and national as they get pulled down

 

[Cactus Jack]

Yeah he means the 12 to 1 compression was too low for the cam's size ... so it lost bottom end torque because the huge overlap of the cam allowed excessive compression bleed off in the lower revs ...

Overlap = (the point where both valves are held open at the same time to allow the exhaust gas velocity to suck aka scavenge the bore clean of spent gasses ... that in turn increases intake velocity and cylinder filling ... sometimes to above 100% volumetric efficiency ... meaning the engine will perform like it has a bigger capacity up high and will rev higher ... Peak dynamic cylinder pressure acts like a rev limiter ... so race cams work by delaying peak cylinder pressure until a higher rev by bleeding off some of the compression ... That makes starting a big bore engine easier , but also causes a loss of bottom end power ... if he raises the static aka built-in compression he'll increase the bottom end torque ... but that could also lower the peak rev limit ...)

A Daytona has the Lifan stud pattern so a TBV2 head won't fit ...

The bore x stroke between the two is so close that it wouldn't make a hoot of a difference ... the power is in the head , intake , cam and ignition system ...

 

[corey58]

The bore x stroke between the two is so close that it wouldn't make a hoot of a difference ... the power is in the head , intake , cam and ignition system ...

what ya on about them blue boxers do the same thing a lot of people claim!

Lifan: 56.5 x 59mm = 147.985cc
Daytona: 57mm x 58.7mm = 149.849cc

thats the CC calculations for any one interested

 

[grnman]

thanks for explaining that cactusjack, i get it now.

i might focus on what u said about head, timing, cam etc
and not just the cc's

go on corey just do it you know you want to. do the lot to ome engine.
but 160cc in your motard for racing would be good
so maybe you will have to do both cranks.

 

[HACKMUNCH]

catus explained what i was gonna resond too about the high duration cam and the 12:1 compression ratio. just for the engine gurus out there the daytona crank is nothing like the lifan, the daytona is a long rod design and the lifan is the exact oppisite, short rod way out on the crank journals. yes we are running the stock daytona head, NOT PORTED. Daytona and the importer did not want us to alter the head, they wanted to see what we could do without any machining or custom work so customers could get the same performance by just bolting stuff together. yes the 167cc gig is as easy as changing your pants, nothing special. the 167cc with z 40 is one hell of an engine for the dirt, has a huge midrange hit. now if you guys motard (thats what i use to do) the 167 with daytona 268 cam has huge topend, spinning well into the 12k range. in a few days we are testing the 167 gig with the new takegawa +r head for jialing stud spacing. it has 30/24 valves and we are gonna test it with the s35 cam, hoping for big power but we will see, then after that we are gonna do the 150 4v dohc and a 167cc 4v dohc.

 

[grnman]

You'll be a busy man with all that testing and engine building on your plate.

my daytona 125 was jumping out of gear last night on the track, so its time to bite the bullet and get the 150cc. (yay an excuse to get one!!) then i can start on some of the stuff we have mentioned in this thread.

question im buying a second-hand 150cc is there two models. i mean did they release the first one that had prob and then all the newer ones are rectified?

When looking at a used one, is there anything i should look for that will indicate how much use the engine has had?

i manly want the bottom end and stuff to be in good order as i will eventually be rebuilding the top with DOHC or high comp 2v.

thanks dudes for helping me out with my q's in this thread. its been a great help and i should have a quality engine as a result. ill get someone to mention your name in my funeral speech.

 

[HACKMUNCH]

lol, well the older daytonas have a different tranny, try and get the new one with 2.65 first gear, it really makes the tranny close ratio compared to the "others" bs close ratio. i also think the newer daytonas have the upgraded crank but i know they did that awhile back. anyone that has the daytona 150 and does the 170kit and the z40 cam and says its not fast enough is crazy as hell. thing rips your arms off, also another thing i forgot to mention we are gonna do once we get the 4v dohc 167 going is swapping out the clutch plates for the thinner 6 plate TB plates (thats how they get 6 plates in the stock basket, not really rocket science.)so we can run the stock basket with 6plates, even though we have not had one clutch slipping issue it will be nice to have 6 plates with 20+hp in the dirt.

 

[grnman]

so you only need to buy the plates as spare parts and put them in the stock basket.

in other words you dont have to buy the whole kit like this.

DHZ Mini Moto

buy the way do you need a special tool to get the whole clutch assembly off?

and hey thx for the 150 advice. ill look out for the 2.65 first gear. what was the older first gear?

 

[pbk]

yes you need a castle nut remover

 

[HACKMUNCH]

well i know its been awhile but with all these damn engine combos we have been trying, we finally we able to find time to work with the takegawa+r head. I laughed the other day while reading through planetclassifieds and someone asked about this combo and BBR said NO. It really was a straight foward install, had to run a 86 link cam chain instead of the 88 that comes standard on the daytona 150. remember the takegawa +r head we are using is designed for for a lifan engine which uses a 32t cam sprocket but the daytona uses a 28t so thats why the shorter cam chain is needed. a good quality jap 86 link cam chain is right around 12$ so its no biggie. we had 1st tried it with the TB 167 gig but due to the 1mm taller jug i could not get the 86 link cam chain to work and the 88 link was way to sloppy. if we had more time we would just cut down the heigth on the 167 cylinder 1mm and things would work out perfect. soooo we decided to give the stock 150 cylinder a try with the daytona HC piston. everything went together like planned, clayed the setup, everything cleared but craig and i felt the intake was a tad to close and with the tiny 4.5mm stem 30mm intake valve, just a little tap will bend the shit out of those things. we decided to add another stock daytona base gasket and finish assembly. so the final combo was the stock 150 jug, daytona HC piston, takegawa +r with s35 decomp cam, stock daytona intake and pe28 carb. the s35 decomp cam is similar to the klx version but i feel has a better slide mechanism and seems to work much smoother. the bike is so easy to kick you can start it with your hand so wee added some oil and the bike fired on the 2nd kick. one thing i noticed is that the valve train is so quite and seems to run very smooth. engine revs quick as hell and sounds impressive. it's gonna be a rev monster for sure, sam is gonna test it sat at ramjams and see how it compares to the other combos. unfortunatly its coming right back apart tuesday for the 4v dohc kit.

TAKEGAWA +R COMBUSTION CHAMBER WITH 30MM INTAKE AND 24MM EXHAUST VALVE

TAKEGAWA +R INTAKE PORT

DAYTONA 150 AT TDC WITH HC PISTON AND 2 BASE GASKETS

TAKEGAWA +R DECOMP MECHANISM INSTALLED

TAKEGAWA +R HEAD INSTALLED ON DAYTONA 150

 

[sean01]

bit confusing reading your post but wat did you do with the crank timing sprocket if you used a different cam sprocket..
and i wouldnt think 1mm difference in the bore height would muck with the timing chain that much.. sht they stretch more than that

 

[grnman]

so did you use 2x base gaskets to make the valve to piston clearance bigger?

can you use multiple base gaskets to lower the compression with the daytona 160 stroker kit?

how many base gaskets can you use on top of each other to do this?