Hey guys. I’ve recently pulled apart 2 old ka’s one sohc and one dohc. From what i undertsnad the block are interchangeable because i want to use a dohc block to rebuild my sohc… I noticed my doch pistons are dished and the sohc ones are flat…would there be an advantage to using the dished pistons in a sohc setup? and ive also heard they early 89 sohc motors had a higher compression then the older ones? does anyone know how they accomplished this and just whats different about the 2?
yes sohc pistons are high compression vs the dohc
do it !
yo go SOHC its WICKED!!
really tho this topic is mad old u should do a search man!!
This is a good topic, I wanna know what’s different betweem the SOHC and DOHC motors, as well as advantages/disadvantages.
first of all the blocks are very similar but not the same. the oil pump setup is different as well as the timing chain setup for obvious reasons. the dohc head can be mated to the sohc block to create a hi-comp motor. there was a user named ‘elroy’ on these boards that did this but i think he lost the motor. not sure why. but the easiest way to build a hi-comp motor is to use your flat top sohc pistons in you dohc engine.
do a search man, this topic has been beaten to death.
edit: give you an idea http://www.son240sx.org/forums/showthread.php?t=27788&highlight=sohc+dohc
peace
Thanks guy, I figured the topic had been brought up before i just couldnt find it…I race a 240 and the rules allow sohc motors only…but i have heard that the early 89 SOHC motors had a higher compression then the late 89-90 SOHC motor…I dont get how thats possible? but anyways i will do lots more research
ps…that link doesnt seem to work lol
it does dude lol
what racing series is this? what mods are you allowed to make to the engine?
peace
first 6 months of production of the 89 had flat top pistons which should give you around 12.1:1 cr with a dohc head
after that they had a slight dish, and should give you around 11.7:1 cr wich a dohc head
just put the sohc pistons in a dohc engine
the biggest problem if you put a dohc head on a sohc block is the timing chain. you have to modify the guides, and tensionor for it to fit, and even then on a rough estimate after 2000km, you’ll wear out the end of the guide in less than 10 000km. so sohc pistons in a dohc engine is the way to go
the engine i had blew its head gasket on account i didn’t get the worn block machined, which was also causing a little much blow buy i think from the rings not sealing well, cylinder walls probably weren’t round.
i did with stuff i kicking around and i was bored i thought i’d give it a try haha
very interesting! now imagine that KA with ITB…swapped into a AE86 or other light machine…haha nice.
lol right on Elroy.I might have to pick your mind a bit more if i actually decide to go ahead with this project…well guys i race at Barrie Speedway in a class called pure stock/mini stock. My bro and I both race 89’s with sohc motors as thats all the rules allow.My bro won the championship in his car and i won the most races in the division with mine.We basically destroyed all the Hondas and VW’s and Mustangs with our beater motors…The rules are basically stock, your allowed to bore .30 tho over and thats about it, and we havent even done that. But this year Sunset Speedway is introducing a new class called Outlaw minis…the rules for this class will allow N/A dohc motors, with basically no rules…cams, headers, head work, racing pistons, computers, are all legal…the list goes on and on…So i guess my next question is whats the easiet way to make big power out of a N/A ka24de without getting into thousands of dollars of machine work?
rebello racing built ka-e engines for a scca spec class. they put out about 270hp at the crank. the engines were very expensive though. you could use a stock block with your flattop pistons, mild port job, 3 angle valve job, a set of cams, nice long tube header, a set of ITB’s and a good tune you might hit 180-190hp if you are lucky. and all what i just said won’t be cheap. nothing NA is cheap. ka engines can’t rev reliably and thats where alot of the NA power comes from. the rebello engines spin at like 8-9000rpms.
peace
Thanks Tosh…The more research i do it seems a N/A ka is not the way to go. These new rules will allow any motor for the make though…So im starting to look at the sr20de and newer ve stuff…
any website i can go to for the info on the rebello engines? I’m guessing about 10 grand or something…nothing I’m interested in unless i could land some major sponsor dollars lol
Ok I found the rebello site and theres nothing about Ka’s, guess I’ll have to phone and find out…I’ll post some pics of our cars when i figure it out tomorrow
wadda bout shaving the heads?
I don’t think you can shave the heads too much because of valve interferance with the piston tops, you could go a few though though.
there is actually a thread out on NICO or something, I’ll try to find it again…basically you can pump out 200hp with about $1000 doing some swappin and modding to a KADE, this setup pretty much will rip a SR or equivalent right off the line cuz of response and such.
I’ll try to post up the link.
**edit, can’t find it…lol
even if you do basic ka-t with no intercooler and a t25 u will make more power and spend half the moneys
he doesn’t care about ka-t, he can’t race his car in that series with the ka-t. I think your allowed using a ka24de even under those rules u wouldn’t be limited to the ka24e, u might even be able to use the sr20det. You just have to prove this car has had that engine in it when in production. KA24DE was, and SR was in Japan and Europe, so they might let you choose on of those engines. Find out, because in that case, a stock sr would probably be your best bet.