Anyone know of a compatible thermostat housing that can be used in place of the 4cyl 2.5 one in a 4.9 swap. I already did it once, the metal is thin and my weld was crap, I tried fixing it with JB weld, no matter what I do though it has a tiny pinhole leak that every once in a while sprays antifreeze all over my engine compartment. I was just at the junkyard recently and no fieros. So does anyone know of an alternative top that I can use with the 4.9 bottom to make a thermostat housing. I would like for it to be of the same size I.D. as the one I am using currently so I dont have to replace the hose.

I was thinking the S10 as it has an iron duke, but based on what pictures I could find on the net its not the same.

Any ideas?

PS- yes I realize I could go with inline fill and a 30 pound cap, think its 30. But I would really just rather not. Don't know why, just strange like that.

I believe that you are better off trying to find a good used original neck. They should be available and not expensive. Post in the mall section and I'll bet that one pops right up.

------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, 3.4" Pulley, N* TB, LS1 MAF, Flotech Exhaust Autolite 104's Custom CAI 4T65eHD w. custom axles, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

Have you tried to coat the inside of the weld with RTV to help it seal?

A weld free option is to use the V6 thermostat housing. Remove the entire Caddy aluminum thermostat base, make a steel or aluminum plate to cap the hole entirely, the V6 thermostat housing has the same bolt pattern as 2 of the 3 holes in the caddy base. Use the plate to cap the hole and then bolt the V6 thermostat on top.



You will need to plug the coolant lines that used to go to the the V6 throttle body, or just cut them off and run the heater hose past them.

For the coolant sensor, you can drill the intake as shown below and mount the 3 wire temp sender in the intake. It will fit in the recessed pocket of the oil filter assy - but it needs to be in the right place:



Another option would be to make a steel plate and weld the upper portion of the thermostat housing to it. This allows you to focus the heat more on the thicker steel and greatly reduces your chances of burning through.

[This message has been edited by fieroguru (edited 11-12-2009).]

I had not heard of people using a plate and a v6 housing. Interesting idea, but I am going for more of a simple solution. Also I am not a fan of the look personally.

RTV though, that is an idea. What specifically do I need? It wont peel off eventually leaking again and clogging the radiator?

Dizzixx take it to a good welding shop and have them braze it up real good, nice and thick bead. The brazing is done with a aceteline , and not a mig/tig or arch welding machine. They burn threw the metal easier than the gas brazing. Clean it up and put some black simi gloss on it. Less than $20.00

Then move on the the next problem

Wont having already welded and then applied JB weld make this difficult? Or will they just grind off the outside and then braze it?

I am sure they will know what they need to do to get it 'Right'. I know the JB weld and RTV will have to come off.
Joe

Available at FieroStore. About $40.

------------------
'84 Sport Coupe (third time's a charm?)