My 3.3L Subie Conversion Thread, Got me some 914rubber stuff Options

[ThePaintedMan]

Kent/Chris,
I have done some research on this phenomenon. There is a website where a few guys who have raced these motors documented their issues and solutions. I'll work on finding that for you in my links when I get home. Essentially the cavitation issue is caused by low volume entering the thermostat housing during sustained high RPMs, which is partially solved by welding a larger diameter inlet on the thermostat housing neck and using a larger hose (1.5 would probably work, but some suggested even as large as 1.75). The other solution is to move the thermostat to the outlet side, prior to entering the radiator. That hose can remain 1.25. I'm planning to do both of these on my build.

The only issue I've thought of is how low the larger hose will fit when run underneath the car. And of course, the Celica radiator outlet would have to be cutoff and the appropriate sized one welded back on.

[Chris H.]

Thanks George. No rush but I'd like to see what you found. That will be especially applicable in your case. I expect you'll be running at high RPMs a LOT. Can't wait for you to get it in the car. The EG33 is quite an engine.

[76-914]

Next step is to pull the engine. Wish I didn't have to but I have a few things to do to it and it's much easier with it out. Will try to get that done this weekend. Really want to drive the car more this year.

I see what you're saying about the AC...you're worried about keeping the engine cool not the car's interior. I'm pretty set on going to wider hoses just to be sure it never gets hot on one of those long drives with the hammer down. What radiator did you pick up?

The Celica GTS one. For $167 shipped with fans. Just like a sore Peter; ya can't beat it! Let me know when you want to order that hose and I'll get you some $$$. I'll probably run the hoses just for comparison purposes. That and to get some "hard" numbers. IOW, what works for the EZ30 using the cooling configuration that "I" have. I've found that what works on someone else car may not be the ticket for yours or mine given slight variations between each vehicle. Should come up with some "hard" numbers for my setup. I'd really like to come up with a proven "package" for guy's that want to convert but not experiment like we do. (IMG:style_emoticons/default/av-943.gif) (IMG:style_emoticons/default/lol-2.gif)
Pull the engine. I know it's grunt work but in a couple of hours it is out and your back in the "work groove". I'd bet you could be finished in a month with full on weekend attacks. Let's get this thing on the road and "out of your hair". (IMG:style_emoticons/default/driving.gif) Oh, I forgot to add; don't know what happened to Doug's project. Poor guy. (IMG:style_emoticons/default/sad.gif) Life jumped up and Bitch slapped the poor dude. He went thru a lot with the divorce and selling his business. I emailed him a few month's back and he did not respond so I left it at that. (IMG:style_emoticons/default/confused24.gif) I'd like to see him get back in the pool. I even entertained the idea of finishing his project. (IMG:style_emoticons/default/blink.gif) Kent (IMG:style_emoticons/default/beerchug.gif)

[76-914]

Kent/Chris,
I have done some research on this phenomenon. There is a website where a few guys who have raced these motors documented their issues and solutions. I'll work on finding that for you in my links when I get home. Essentially the cavitation issue is caused by low volume entering the thermostat housing during sustained high RPMs, which is partially solved by welding a larger diameter inlet on the thermostat housing neck and using a larger hose (1.5 would probably work, but some suggested even as large as 1.75). The other solution is to move the thermostat to the outlet side, prior to entering the radiator. That hose can remain 1.25. I'm planning to do both of these on my build.

The only issue I've thought of is how low the larger hose will fit when run underneath the car. And of course, the Celica radiator outlet would have to be cutoff and the appropriate sized one welded back on.

Sounds correct. Find that article and post it, Jorge. Nothing like new info! (IMG:style_emoticons/default/drooley.gif)

[Chris H.]

Next step is to pull the engine. Wish I didn't have to but I have a few things to do to it and it's much easier with it out. Will try to get that done this weekend. Really want to drive the car more this year.

I see what you're saying about the AC...you're worried about keeping the engine cool not the car's interior. I'm pretty set on going to wider hoses just to be sure it never gets hot on one of those long drives with the hammer down. What radiator did you pick up?

The Celica GTS one. For $167 shipped with fans. Just like a sore Peter; ya can't beat it! Let me know when you want to order that hose and I'll get you some $$$. I'll probably run the hoses just for comparison purposes. That and to get some "hard" numbers. IOW, what works for the EZ30 using the cooling configuration that "I" have. I've found that what works on someone else car may not be the ticket for yours or mine given slight variations between each vehicle. Should come up with some "hard" numbers for my setup. I'd really like to come up with a proven "package" for guy's that want to convert but not experiment like we do. (IMG:style_emoticons/default/av-943.gif) (IMG:style_emoticons/default/lol-2.gif)
Pull the engine. I know it's grunt work but in a couple of hours it is out and your back in the "work groove". I'd bet you could be finished in a month with full on weekend attacks. Let's get this thing on the road and "out of your hair". (IMG:style_emoticons/default/driving.gif) Oh, I forgot to add; don't know what happened to Doug's project. Poor guy. (IMG:style_emoticons/default/sad.gif) Life jumped up and Bitch slapped the poor dude. He went thru a lot with the divorce and selling his business. I emailed him a few month's back and he did not respond so I left it at that. (IMG:style_emoticons/default/confused24.gif) I'd like to see him get back in the pool. I even entertained the idea of finishing his project. (IMG:style_emoticons/default/blink.gif) Kent (IMG:style_emoticons/default/beerchug.gif)

Will do on the hoses. And the engine (IMG:style_emoticons/default/biggrin.gif) . Supposed to be 50ish here this weekend. I think the last post I saw from Doug he had gotten a really good CFO gig somewhere. Dream job. I hope he's just making so much money he can't be bothered with us (IMG:style_emoticons/default/biggrin.gif) (IMG:style_emoticons/default/lol-2.gif) (kidding...if you know Doug it's hilarious). He'll be back. They always come back.

George when is your engine gonna be ready?

[ThePaintedMan]

Found it! The impetus for all of this is that the Suby water pumps are actually too efficient at higher RPMs, perhaps 6000+. The restriction of the thermostat and pump inlet cause a backup of water that at a certain point can't keep up with the pump. On a street car, under 6k, no problem. But on a car seeing extended RPMs, the VE of the pump and the previous restriction causes cavitation (bubbles), which then boils the coolant in the motor and eventually a large air mass in the engine - not good. So a 50mm, or 1.75 in+ inlet and a relocation of the thermostat to the engine outlet/radiator inlet is the solution.

Well documented here:
http://www.mrtperformance.com.au/resources...-boiling-theirs

Other supporting articles:

http://www.subaru-svx.net/forum/archive/in...hp/t-61824.html

http://thefactoryfiveforum.com/showthread....ms-when-tracked

http://www.dirally.com/forums/archive/index.php/t-12965.html


Not sure when the engine will be ready. Still fighting through deaths in the family, low pay and lots of diapers to buy/change. I live vicariously through YOU GUYS! (IMG:style_emoticons/default/smile.gif)

[76-914]

Found it! The impetus for all of this is that the Suby water pumps are actually too efficient at higher RPMs, perhaps 6000+. The restriction of the thermostat and pump inlet cause a backup of water that at a certain point can't keep up with the pump. On a street car, under 6k, no problem. But on a car seeing extended RPMs, the VE of the pump and the previous restriction causes cavitation (bubbles), which then boils the coolant in the motor and eventually a large air mass in the engine - not good. So a 50mm, or 1.75 in+ inlet and a relocation of the thermostat to the engine outlet/radiator inlet is the solution.

Well documented here:
http://www.mrtperformance.com.au/resources...-boiling-theirs

Other supporting articles:

http://www.subaru-svx.net/forum/archive/in...hp/t-61824.html

http://thefactoryfiveforum.com/showthread....ms-when-tracked

http://www.dirally.com/forums/archive/index.php/t-12965.html


Not sure when the engine will be ready. Still fighting through deaths in the family, low pay and lots of diapers to buy/change. I live vicariously through YOU GUYS! (IMG:style_emoticons/default/smile.gif)

That's a good read, George. Thx for the post. After reading those it seems I am on the right track. The thermo relo / upsizing the "old thermostat housing" looks to be key. For those reading these links: skim down about 4/5's of the way down the last link. Doesn't touch on cooling till the end of the article. Thx again. (IMG:style_emoticons/default/beerchug.gif) Kent

[914forme]

I thought this was a know issue, and you guys had read this stuff. Sorry.

In reality, if your planning lots of high RPM stuff, I would suggest 2" in, and move the thermostat for good measure.

Sorry again for not clueing you all in on this. (IMG:style_emoticons/default/sad.gif)

[ThePaintedMan]

Not a problem Kent. Chris - sorry we're hijacking your thread.

Stephen - my question still is, will I still be able to reliably run a 2" hose underneath the car without the danger of it rubbing/getting caught on stuff? Also, on the Celica radiator, is there enough room to weld on a new 2" outlet?

[mgp4591]

Not a problem Kent. Chris - sorry we're hijacking your thread.

Stephen - my question still is, will I still be able to reliably run a 2" hose underneath the car without the danger of it rubbing/getting caught on stuff? Also, on the Celica radiator, is there enough room to weld on a new 2" outlet?

With the added volume of a 2" hose I would think the (potential) restriction issue of running through the longs would be resolved and eliminate your under car issues. So dumping the stock thermostat location and relocating to the upper engine bay is a viable solution? Or would another location be even more effective? My EG33 is still out of the car and I'm looking around for a solution to getting the car where I can weld in my floors and other strong bits - that's when I want to install the coolant hoses in the longs where I can get to them easier. (IMG:style_emoticons/default/welder.gif)

[76-914]

Not a problem Kent. Chris - sorry we're hijacking your thread.

Stephen - my question still is, will I still be able to reliably run a 2" hose underneath the car without the danger of it rubbing/getting caught on stuff? Also, on the Celica radiator, is there enough room to weld on a new 2" outlet?

With the added volume of a 2" hose I would think the (potential) restriction issue of running through the longs would be resolved and eliminate your under car issues. So dumping the stock thermostat location and relocating to the upper engine bay is a viable solution? Or would another location be even more effective? My EG33 is still out of the car and I'm looking around for a solution to getting the car where I can weld in my floors and other strong bits - that's when I want to install the coolant hoses in the longs where I can get to them easier. (IMG:style_emoticons/default/welder.gif)

Didn't one of those articles speak to keeping the newly located thermostat housing close to the engine? It's not a high jack if it's informative. (IMG:style_emoticons/default/rolleyes.gif)

[914forme]

2" would be hard to get through the logs. But that being said let us do a little math.

2" hose has an area of 3.14", that is pretty large area. You can get close with a square 3"x1" AL. Rectangular Tube. That reduces your ground clearance issues going along the bottom. Rick did something similar with the Alien. I think Rick used tube, we talked about it last week.

Most people would say I'll run 2 1" tubes but that give you an area of 1.58", so you would need to run 4 of them to get resemble close. You can not fit 4 1" tubes down the logs. You can do two per side.

(IMG:style_emoticons/default/idea.gif) Boxster Rads again. (IMG:style_emoticons/default/huh.gif) (IMG:style_emoticons/default/poke.gif)

So the lowest profile method would be rectangular box.

Now if you have the logs wide open, then running a 2" Tube through there would be about perfect.

If you where not worried about rust, a 2.25" "piece of DOM would also work And I have thought about this also, as I need a raised section to bring the shifter up etc. If built correctly it could provide extra support for the chassis also. Same idea as the Early Lotus Elan chassis, that had a box section, that provided the strength of the chassis. Herb Adams also did a kit car "JackRabbit" in the 80s with this same idea, stiff as all git out.

]

BTW, do not follow this builders lead and use thin wall tubing for a roll cage. See the small dents in the upper bar, and how he swaged the petty bar and bolted it into the chassis in a single shear. Not the proper way to do that (IMG:style_emoticons/default/huh.gif)

[914forme]

Didn't one of those articles speak to keeping the newly located thermostat housing close to the engine? It's not a high jack if it's informative. (IMG:style_emoticons/default/rolleyes.gif)

Yes it is right off the cross over pipe right in front of the engine. The upper one, You can not block off the heater tubes, I am sure none of you have. But that is just a reminder not to cap them, engine would get hot very fast, block would be pressurized, and could help cause a leak. Suction hose would also go into a vacuum state, and maybe collapse.

This engine pumps ton of water or would like to. I think if you had a flooded basement, it might be better to hookup a long 2" hose, fire up your 914 and let it run until you pumped the basement close to dry. (IMG:style_emoticons/default/confused24.gif)

[Chris H.]

Not a problem Kent. Chris - sorry we're hijacking your thread.

Stephen - my question still is, will I still be able to reliably run a 2" hose underneath the car without the danger of it rubbing/getting caught on stuff? Also, on the Celica radiator, is there enough room to weld on a new 2" outlet?

No need to apologize. Chat away everyone! It's very motivating. Gives me great ideas.

2" hose is HUGE man!

[BIGKAT_83]

15k miles on my Subaru conversion with no cooling problems what so ever. It ran at the thermostat180 on 100 degree summer days in Atlanta freeway traffic. I was using 3/4 and 7/8 size hoses to a 10 x 26 radiator.
.

[DBCooper]

I'm at 1.25" and 1.5" and also no issues, though through a big honkin' Renegade V8 radiator.

[76-914]

15k miles on my Subaru conversion with no cooling problems what so ever. It ran at the thermostat180 on 100 degree summer days in Atlanta freeway traffic. I was using 3/4 and 7/8 size hoses to a 10 x 26 radiator.
.

I'm running the same Bob but if I maintain a high RPM uphill in 97F+ I will overheat. Bob, did you ever get the AC finished in that car?

[ThePaintedMan]

Bob, I think the main concern, at least on my part, is how it will cool at extended 6k+ driving. I for one would like to get it right the first time as I don't have the expendable income to redo the system over. However, when I'm done, if it stays cool on my car, on the track, it should be a good baseline for everyone else.

That being said, Bob's car was a work of art - truly beautiful engineering. I am tempted by his own results, but because my car will see very different driving, I am at least a little concerned about getting the hose size right.

The square tubing is a good idea, except for the bending required to get it to follow the contours under the car. I'm interested to try fitting the hose in the longs, but that's also just one problem to overcome. After that, one would still have to figure out how to route it past the gas tank and to the radiator.

And yes, the inline thermostat should be located as close to the water outlet from the engine as possible. That hose inner diameter (stock) is 1.5 inches, or 39.5 ish mm for those keeping track at home.

Finally, I'm usually not one to try to re-engineer something that the factory guys spent so much time on. However, it's clear that Subaru never intended these engines to see that many rpms for that length of time. So I'm glad I have you guys to help sort through this one.

[ThePaintedMan]

By the way, Chris, have you ever heard of this one regarding the hesitation you were talking about before? I wonder if this is somehow linked to the lack of a VSS, or masking it somehow?

http://svx-iw.com/svxiw/article/?article=31

[jimkelly]

fwiw, I've been running a celica radiator with my chevy v8 for 2 months now. I have a 190 degree thermostat on the engine and a 190 thermoswitch for the fans. engine temp go to about 210 before fans kick in. i'm thinking I need to drop to a 180 degree thermostat and thermoswitch before summer rolls around.