Why did you port 4V heads? Also a turbo that is too far from the exhaust ports will lose too much heat and won't work very well, if at all.


BTW one TO3 isn't enough.



_______________________
89 5spd Coupe, 351C EFI Spyder, QA1 tubular K-member, 5 lug conversion, 13" PBR calipers, 17x9 95 Cobra R's, AGS 4 suspension, 3.55's.
80 LX, 351C w/GForce T5, 750 Speed Demon, 11:1 cr, QA1 tubular K-member, 5 lug conversion, 17x9 95 Cobra R's, 3.55's

<font size=-1>[ This Message was edited by: 1 Bad 88 GT on 2/18/04 2:01am ]</font>

 

http://www.turboneticsinc.com/guidelines.html
just in case you hadn't checked.

 

For one thing it was my first time rebuilding an engine. Second, by word of mouth I heard that 2v heads don't perform the best at high altitudes. My altitude is 5000 FT. The air pressure in my area is barely 8 psi.

On the Turbo Aspect, What does the heat have to do with spinning up the turbine. The only thing that I could thing of was the loss of air pressure cause of the exhaust pipe extension. Correct me if I am wrong, I am just learning. But if I ran two exhaust pipes (one for each header ) to a dual inlet turbine housing, wouldn't I be able to maintain a good pressure.

Yeah I haven't fully decided on the size of the turbo. I am still researching everything.

 

Sorry, after thinking over the Turbo heat thing. I understand what you are saying. If the turbo is to far from the engine then the air condenses when it starts to loose the heat which cuts back the amount of air pressure to turn the turbine. Correct?

 

sorry again used wrong word, condensed I meant volume

 

FI on a 351C will cost you bucks. The cheapest is to source a TBI setup and run it on an intake, probably a dual plane. Otherwise, you'll have to buy the Spyder or make your own. There is no other option. The Pantera folks do it a lot, but $800~1000 for a manifold doesn't scare them.

Don't know why anyone would tell you 2Vs are any worse than anything else at altitude. If anything, the additional torque from increased mix velocity would help the motor.


Visit the Cleveland forum.
http://www.351cleveland.net

 

I should of researched it more, before paying all the money to have the work done to the heads. ckelly What do you mean by TBI, ( Throttle body injection? ). I don't see any reason why I couldn't do the TBI. It would be a little less complicated.

 

Yep - throttle body. People tell me they find 'em on eBay often for cheap.

Here's a recent thread on the subject:

http://www.network54.com/Hide/Forum/thread?forumid=119419&messageid=1075687448

 

Im willing to bet that a 351C at +.040" over is gonna have some areas in the cylinder walls that are paper thin. Add any kind of boost or high cylinder pressure, and I see a crack in your future!

 

The turbos air charge isnt affected very much by the exhaust heat. The increased air charge temp comes from compressing the air. Also, it is the exhaust heat moving at high velocity that moves the turbine wheel so fast. You would need a hell of a lot more cold air to do the same thing that a little hot air will do. Youre going to need a much bigger turbo also, have you thought about a dual system?

 

I am up for any suggestions. Also I am not to worried about the block, I have to get a new one, I think I ceased a piston in the one I just rebuilt with .040 over. I know of a couple around my area. I have a book I am reading on Turbo's called "Maximium Boost" by Corky Bell. I haven't thought much about a dual Turbo system cause I didn't think about how much air I am really going to have to push. If I could get better torque and performance out of Two turbo's i will do it. I am up for anything right now, I am just at the research point. What is the best way to run a Dual Turbo system? a header to each Turbo where each turbo is the same size? or vary the turbo sizes?

 

Currently I'm mocking up a TT 351C for my 84 LX. I am using a pair of TC turbos and am working on the header layout right now. I am trying to build the system so I can retain PS and AC, it's not looking good at all for the AC at this point.

EFI is quite simple. You just need an EEC setup and drill/weld a single plane intake with the injector bungs, install the sensors, mod a TFI dist and fire it up(slightly condensed instructions).

 

Sorry, seems like a stupid question to ask, but I haven't been able to find the exact meaning of EEC IV, What is it? all these 3 letter abreviations get a little confusing. Also about the rear mounting of the Turbo, check this out. A guy in my area is installing rear mounted Turbos and is making some good money at it, I have riden in the Firebird on the homepage. It has the rear turbo with Methenol injection, and it hauls A$$.

http://www.ststurbo.com

 

Bad, what are your specs on your heads, Cylinder size, Intake, and cam?

 

Standard bore 2 bolt block, about 10.6:1, stock 71 4V CC heads, stock pedestal rockers, Older Lunati .509" lift cam(reason for good torque), CHP modded carb intake with 30# injectors, 75mm MAF, 70mm TB, 1 7/8" Hedman Husler 351C swap headers 85620, 2.5" X pipe, 2.5" 2 chamber Flows, I have a custom burned chip that keeps everything in check.


It put out 350.6rwhp @ 5900 and 363.8rwtq @ 5000.


I am looking at the WMS EFI system for the 80 LX as it would be easier to install in kit form rather than working with the cluster phuck stock EEC harness. For now it'll stay carb'd to get some miles on it, then maybe this spring/early summer I'll change it over as well.

 

Hey don't know much about turbos but wouldn't a turbo mounted away from the engine have awful throttle response?

 

Depends on the size of the turbine, but yes turbo lag could be a problem.

 

with a T3 you'd be lucky to get enough airflow out of it to feed 1/2 of the 351c. It was designed for 4-cylinder cars and I think the biggest I've seen a T3 on was a 2.6L Chrysler. You'll need 2 of 'em to actually work, or one large single turbo, which is what I did. Also, that large cam will have to go as the excess overlap tends to allow the intake pressure to escape right out of the exhaust valve when both valves are open. Then it ignites in the header and can overspeed the turbo(s) creating a potential disaster (compressor wheel disintegrates sending parts into the motor---and if you're lucky you'll just get a few bent valves). As for turbo mounting, you'll want it as close as you can get it to the heads so it'll spool quicker. Granted, all turbocharged engines have some sort of lag, but it can be minimized with some research and planning. Lag can be a major PITA when driving on the street. There are some good sites out there for reading up. Here are a few

http://www.toohighpsi.com
http://www.geocities.com/mavman687

Good luck!

 

Mavman,

I noticed on your webpage, you used a Turbo from a Diesel. As far as I have heard, you can't use a Diesel turbo engine cause of some seal. Of course you have proved that assumption wrong. But have you ever heard the same rumor.

Also, I mentioned before a company around my area that is installing rear mounted turbos. This is from the website.

With the turbo so far back, don't you get a lot of turbo lag?
No, our turbochargers are sized to operate at this remote location. Just like any turbocharger, once the turbo is up to temperature and in the rpm range for which it was designed to operate. The boost comes on hard and fast. All of our systems will produce full boost below 3000 rpm.
If you were to take a conventional turbo and place it at the rear, you would have lots of lag and consequently, our turbo wouldn't work properly if mounted up front. For more information and actual numbers and times of turbo lag on one of our systems

I am going to check out a couple V8's that have this setup installed to see if I can actually get some actual numbers off the Turbo.

 

they put the turbos at the rear. I did that on a '74 Maverick with a 250 straight 6 and yes it works, but from the time you floor the pedal and the time there's actually some pressure in the manifold is about 4-5 seconds, an eternity. Also, because the turbo will be so small in order to work with a "cold" exhaust at the rear (it will rely entirely on flow, not exhaust gas velocity--which is how turbos are designed to work) it will become a choke point in the exhaust system as RPM rises. There's 2 reasons why not to do it that way. The 3rd, how are they going to route return oil from the turbo back to the oil pan without using a scavenge pump?

Seems like a lot of unnecessary plumbing and headache to me. If there's room under the hood, put it there, it works SO much better. If they worked so well out back, then all diesel trucks would have them at the top of the stacks. If you look closely you'll see that most big trucks have a REAL short exhaust manifold. In fact, some actually have the turbo mounted within 1-2" of the center exhaust ports. This allows them to use a larger turbine which will not become a restriction in the exhaust system, adding HP and torque at higher RPM.

Not saying it can't be done. I'm sure it can, but why reinvent the wheel when a proven design is already out there? As far as using diesel turbos with a gas engine, you can do it just fine. Diesel turbos usually use a metal seal at the compressor, so if you use the turbo for a draw-through (where the carb is before the turbo) than it usually will pull some oil through that seal unless it is changed to a different design. This is not a problem with blow-through (carb or throttle body AFTER the turbo) system. Blow-through is the most common and easiest method.

 

Well part of the problem I am having, is I don't have enough room under my hood. I could always re-route my battery, but that still isn't enough room. Thanks for the input guys

 

What kind of car is this going into? A turbo mounted at the rear of anything other than a Pantera would seem to be nearly impossible. Maybe Im wrong?

 

perhaps you could mount the battery at the trunk, then put the windshield washer/overflow bottle somewhere else? That's what I had to do. The only car I've seen that doesn't have enough room under the hood would be a Maverick, early Comet/Falcon, '64-'65 Mustang, etc. with a 351w. The clevelands have their exhaust ports pointing more downward and actually have more room for exhaust, though plumbing for a turbo manifold(s) would not be fun.

With the 4V heads, I see no reason one couldn't make 600+ HP with the right setup. To top that, it would idle smoothly (great sleeper!)

 

On 2004-02-18 21:18, mavman wrote:
The clevelands have their exhaust ports pointing more downward and actually have more room for exhaust, though plumbing for a turbo manifold(s) would not be fun.

With the 4V heads, I see no reason one couldn't make 600+ HP with the right setup. To top that, it would idle smoothly (great sleeper!)

I'm working on it.

 

I have a 73 Mustang Grande with the 351C. I can move the battery to the rear of the trunk, but it will still be close. Also I don't even have a coolent overflow( I got one coming though ) or a washer fluid canister. I have my MSD 6AL mounted where my washer fluid went. As is the engine is allready a tight fit. I had to wench the engine left and right just to get the headers to slide up from the bottom, and that took me a good amount of hours and bruised knuckles.

Mavman, what would be your specs on a good setup for 600 hp. I am all ears and I have to do a complete rebuild again, with no boring this time ( I couldn't keep the engine cool last time ).