SOME PEOPLE say its ABSOLUTLY NECESSARY to have a vtec water nd oil pump for an ls/vtec build, some say no.Its a 94 integra ls block,gettin a 16a1 head. Being this is my first type of build like this idk...please answer this question correctly, and if u have something else to add other than just an answer please do. Also not to be an asshole but if u honestly dont know please dont answer...thanks

 

no its not NECESSARY to use vtec,i use ls water pumps just cause they cost less and the timing belts are less never had a problem,but as for oil pumps i try to only use obd2 oil pumps

 

The reason given for running the vtec water pumps is that they run slower than the LS pump. That means less chance of cavitation at higher rpms. If the pump cavitates, it isn't moving water.
The LS motors didn't run at such high rpms, so it never ran fast enough to cavitate.
Apparently, Honda discovered this at some point, as it would have been easier and cheaper for them to use the LS part. I have heard that the b17 came with the LS pump.

That said, as rangcrx reports. people run the ls pumps on ls/vtecs and report they work fine.

I had heard the only dif between the ls and vtec oil pumps was the washer on the relief valve for the paypass. Take the washer off an LS pump and you have a vtec pump, so the story goes.
But I got curious and tore down both obd1 pumps once to inspect inside and found the gears were different in size, at least in the two I had, so there appears to be more to it than that.

Starting in 1996, both LS and GSR were using the p72 vtec pump.

 

I don't know much about this but i always see people going in the route of type r oil and water pumps if your budget allows..

 

^and that's why I say don't the typeR oilpump is the same as a obd2 and waterpump is vtec so that's like 75bucks more spent then needed then u pay 25more for a timingbelt that's crzy the beairn and seals in a ls water pump are the same as the vtec only thing differt it the gear size

 

i just did it for peace of mind, but you dont really need it.

 

^ thanks alot guys

 

I would do the water pump just for assurance but as rangcrx states...do the obd2 oil pump, I don't believe a vtec oil pump is necessary though I have seen many people do it.

 

An obd2 oil pump is a vtec oil pump. It's a p72

 

Someone did there homework.I was hoping to be the first to respond with the cavitation issues with the waterpump at over 7000 rpms but I was beat!Civicized Know's what he is talking about,in fact he's making me rethink way's to re-invent the wheel in a matter of speaking.