jakes_runner

I hope you guys can save me some time! I recently bought a 93 4runner with a blown head gasket for 400 bucks and the plan was to rebuild it and sell it off (due to the fact that I dont need two of them lol) anyways I had a set of heads from a 90 that I knew were good that I decided on using. Well to make a long story short the heads are all set in and all I have left to do is time the stupid thing but theres one problem.

I forgot about that in 93 they changed over the idler pulley set up . Just my luck and the heads off the 90 dont have the hole drilled for the 93 type idler pulley!

So I need some advice from the experts here!
What should I do?
-I have the bit and tap I need but I dont feel very comfortable drilling that hole into my head unless people have done it before. (Plus i dont know how strait i would get it!)
-Could I just pick up a idler pulley kit and acquire the bracket for the spring to attach to
-Or is that fan pulley bracket to big and will need to be changed out also?
-Are the lengths of the belts used on the 90 any different than the 93 due to the different idler pulley set up? If so can it be converted



Any suggestions would be greatly appreciated! Im getting tired of working on this thing! And thanks again to everyone for having and awesome knowledge base here!

DH6twinotter

The fan pully bracket on the '90 is slightly shorter on the top side and you will not be able to use the upper timing cover off of the '93 motor, unless you decide to modify it. And even then, I don't think all the timing cover bolt holes line up with the fan pulley bracket. Also, the fan pulley bracket off the '93 has a hole on the bottom right corner that the '90 does not have. I'm not familiar how the '93 tensioner works, but I believe the hole has something to do with the tensioner. One last thing, the '90 fan pulley bracket has a small curved section notched out that allows you to tighten down the bolt on the tensioner pulley, but the '93 does not have this. I believe both bracket have pretty much the same bolt pattern, so it may bolt up.

One other thing, if my memory serves correctly, the '90 tensioner rotates on a pin that is set into the waterpump. You may want to make sure you have this pivot pin on your '93 waterpump.

IMHO, you would be better off trying to use '93 tensioner, if possible. Maybe somebody else will pitch in if this is possible or not. I dunno how they work or how they are mounted.

If you do decide to use the spring type tensioner on the '90, you will probably have to replace the fan pulley bracket, upper timing cover, and possibly the waterpump (if it doesn't have that pin). Even then, I'm not 100% sure it would work.

I have both a '90 and a '93 fan pulley bracket. If I can find my camera, I'll see if I can post some comparison pictures tomorrow. I've just got to find my camera.

I don't have an answer to the first two questions.

Just my $.02.

jakes_runner

Thanks for the reply! I dont get any better idea soon I think im going to fab up a bracket off the old 93 head to bolt into the 90 head that is currently installed on the vehicle to make sure that I drill the hole strait and to the proper length?Good idea or Bad idea?!?!?!?

jakes_runner

Well ive decided that im going to try and drill the head. The plan as of now is to rig up something that will bolt onto the head (will using the 93 head as a pattern) so I can get the hole in the exact spot on the 90 as the 93. I will take some pics and try posting them later. I guess no one else has ran into this problem so hopefully I can add something to the forum that I have taken and learned so much from. If anyone still has any other ideas though feel free to speak your mind