wrenchtech

I was wondering if a 5VZFE short block can work with 3VZE heads to make a hybrid 3.4 SOHC engine? The 3.0 heads are a real bottleneck, so it isn't the best idea, but I'm just wondering. -- Matt

mastacox

Nope, and its a terrible idea anyway.

wrenchtech

I appreciate your opinion. Now how about some details, just to help me understand. -- Matt

thefallman

actually the heads should bolt on as the block configuration is pretty much identical to the 3.0 3vze. but u would have a problem with the fact that the domes in the head are to small and a few other issues with the heads actually sealing down properly. mostly likely if u actually made it you would have headgaskets blowing left and right.

thefreqofnature

NO!

wrenchtech

The combustion chambers in the heads would certainly be a few millimeters smaller in relation to the piston diameter. I wonder if the domes on the pistons are so different that there would be an issue? Probably totally different, four valves versus two.

I'm in for a 5VZFE swap or two as soon as I can afford it. -- Matt

Elton

the 3.4L has 4 cams and 24 valves enough said

91_TOYOTA_4x4

what??? thats like saying let put 1914 model A heads on a hand built Ferrari engine?? lmao but seriously the 3.0L or 3vze heads are the worst part of a 3vze, thats why they made the dual overhead cam heads and kept the 3vze block. so yes i think it is possible but a very bad idea lol. now what you should try and do is put 3.4 heads on a 3.0L haha

yotaman85

the real question is can you fit 5vze heads on a 3vze motor..

thefreqofnature

YES! THAT, is the question!

But, NO!

yotaman85

you can, actually. but it involves new timing belt guides and front end alignment stuff. the 3vzfe heads are allot easier, but still not easy.. I still wanna build a frankin veezee...

thefallman

problem with putting 5vz heads on 3vz block would again be dishes in the heads but the reverse problem this time as the dishes in the 5vz heads would be to big and would line up with the sealing metal rings on the head gaskets.

yotaman85

thats why you use 5vze head gaskets...

yotaman85

and bore the 3vze .20 over..

thefallman

so what about the fact that ur going to have compression on the sides of the piston and heat because fuel and air are going to be in that open space around the top of the piston

yotaman85

??.. do you mean the head gasket from the 3.4 will still be bigger then the 3.0 after the bore?

yotaman85

the 3.4 head gasket is about .20" bigger then the 3.0. so it will line up-ish...

thefallman

yes 0.20 not 0.020 first is 20 hundreths second is 20 thousandths. 5vz bore is 94mm while the 3vz bore is 90mm. you cannot bore a 3vz to 94mm with out the cylinder walls becoming to thin and having lots and lots and lots of issues. 4 millimeters = 0.157480315 inches. so actually its only 0.16bigger but thats enough that you couldnt bore it the biggest bore job your going to do on a 5vz is 0.040 over. even on the old iron big blocks the most they went was 0.080 over which is still half of what you would need to make a 3vz 3.0 into a 3.4 3vz

thefallman

so yes the 3.4 head gasket will still be bigger then the 3.0 even after you have bored it as much as possible.