dsol

so i put a b20 into my 97 civic ex and im trying to find the right rad hose. right now i have an em1 upper hose, but i it has been shortened (due to bends) and my rad does not sit straight up and down due to its shortness. i ordered a b18 upper hose and it could work bend wise and length wise...but the hose size itself is to big for the radiator. after looking it appears that i need to find an upper rad hose that has 2 different sizes?!?! the connection on the head is larger than the connection on my radiator. im using an em1 radiator. is there a hose for this swap? or an adapter to put on the radiator to make it larger?
Any help is gladly appreciated, been fighting this one for too long...

tony_2018

I used the integra hoses and made it fit, with em1 radiator.

1999 Civic Si

I can't help you on what hoses to use, but there are two different sizes for the half size civic radiators, I am assuming you are using a stock or OE style radiator. The d series radiator is a 1-1/8" inlet & outlet, while a b series is 1-1/4" inlet & outlet. Basically all aftermarket OE style radiators use the 1-1/8" inlet/oulet. So you will either need to get a good hose clamp and hope it squeezes the larger hose down tight or look into the rubber slip on adapters that come with some aftermarket OE style radiators. If you are using or plan on using an aftermarket all aluminum radiator you are fine, if I remember correctly everyone uses the 1-1/4" inlet/outlet on those except for one or two companies that offer the smaller size along with the larger size.

Now if the em1 radiator you are using is an OEM one & the hose is still to large then I don't know what to tell you, but more than likely it is an OE style one and was replaced at some point and time.

When I replaced the one in my EM1 I bought a spectra premium brand radiator and it included the slip on adapters to allow a 1-1/4" diameter hose to slip on and tighten properly.

dsol

Thanks!! I am going to look at the adapter kits and see if i can find 1 the right size. I have had a few people tell me to invest in a good hose clamp and just clamp it down, but that seems sketchy to me.

egsleepercivic

You can find the radiators with the larger diameter inlets , the del sol Vtec models with DOHC had them as well, just have to read the specs, I have also used worm clamps in the past without issue