Turbo 340 longevity,heat & build questions from a newbee.

[triggerfish]

I'm considering building a 340 T/A block, twin turbo, but am wondering about longevity & heat
issues from the pressure & heat a HP turbo motor produces. Not being too schooled on forced
induction builds, I sure appreciate any info to my questions.
1. With the headers being so close to the hood (fiberglass T/A hood), will the extreme exhaust
temps melt the hood or cause paint issues? (My bro always had paint problems with the turbo on
his 550 hp 930 Porsche.)

2. Even if I O-ring the heads or block, use a stud girdle & high quality internals, will a cross
bolted stroker T/A block (416 cu in), live with the power a twin turbo would make?

3. What mods do you use to eliminate leaks & heat from high pressures?

4. what's the best intercooler setup to use.
Thanks for helping a novice.

[zin]

Lots of subjective stuff here... I will say you'd want to insulate the hood with the reflective insulation, that's kind of a given, especially if the heat won't be given a "way out" like the "grill" on most of our turbo cars from the 80s.

Intercoolers?.. As big as you can fit, where you can fit it, if going air to air. If going air to water, you have much more freedom and smaller pieces, though there will be more to it, in the form of pumps, heat exchanger hoses, holding tank...

How much will it take? That's the $10K question!... Always! The short answer is all of it, if "it" isn't too much! Really, from what you've described of the short block, it should be pretty stout, and will probably be limited by the block itself, assuming the crank is not just a modified stocker, otherwise it'll be a toss-up between the block and crank as to what would go first.

The real question to be asked and answered here is: What's the goal? A fast street car? A full-on drag car?

If it's just going to be something fun on the street, I'd build the engine as strong as I could reasonably afford, starting with a good block, that's been properly machined to make it "square to the world", same for the crank, and some good rods/pistons... But even this may be over-kill for just a "fun" project...

Kind of like my idea of adding a couple of early T1 turbo's to my 318 Cordoba! I was just going to slap them on, run minimum boost and see what happens! I imagine it would be pretty fun, but not anywhere near what it could be, but that wouldn't be the point of what I have in mind..

Any way you go, you'll want/need a good oil cooler, the turbos will be heating the oil quite a bit, and oil failure is almost as quick a death as detonation, which is the other side to be addressed. An MSD with boost retard would fix that issue, might even consider adding water injection, but that's a maybe, the ignition retard is a "have to".

Any way you slice it, sounds like a pretty fun project!

Mike

[turbovanman²]

What he said. Unless your going stupid boost, then properly prepped surfaces with a cometic and studs will be fine. Forged pistons are a must and of course, gauges. Coatings, etc will play a role in heat output but if properly built, you won't melt your fibreglass hood.

[RoadWarrior222]

Any way you go, you'll want/need a good oil cooler, the turbos will be heating the oil quite a bit, and oil failure is almost as quick a death as detonation, which is the other side to be addressed. An MSD with boost retard would fix that issue, might even consider adding water injection, but that's a maybe, the ignition retard is a "have to".

Interesting thing here, NASCAR reduced rad size to keep drafting speed down, so the "pushing" car would overheat in the dead air, but the teams discovered they could make it up with oil coolers. So if you have a situation where you can only get so big a one piece radiator without ugly mods, then go big on the oil cooler.

[zin]

That's true, all engines are oil cooled to an extent, but normally you'd want the oil side running warmer than the water side... But if the goal is to increase total heat rejection, even adding airflow over the block would help!

Heck, I bet those guys would (maybe even are) adding a "power steering cooler" to the coolant lines, but actually use it to pull heat from the coolant! Heat exchangers work in both directions, a fact not lost on those "boys"!

Mike

[Kryp2nitE]

Is the T/A block the one with the weird offset pushrods?

I think if you haven't started the build I'd start with a magnum 360. More cubes, hyd roller cam.

[440dart]

Is the T/A block the one with the weird offset pushrods?

I think if you haven't started the build I'd start with a magnum 360. More cubes, hyd roller cam.

But then you start with a cast crank not good if you build alot of low end power dapending on turbo choice

---------- Post added at 05:19 PM ---------- Previous post was at 05:15 PM ----------

go to forabodiesonly.com sign up theres alot of help and alot of boosted mopar setups on that site they have a forcedinduction section. Some guy made 900+hp with a 340 on there years ago i would asume custom pistons and rods but 500-600whp is nothing to sneez at and can be easily done with about any performance oriented v8 mopar at a resonable cost and still be very streetable.

[Kryp2nitE]

But then you start with a cast crank not good if you build alot of low end power dapending on turbo choice ​

Agreed but a forged crank for the 360 is cheaper than the $$$ you are gonna drop on T/A Parts. ---- you could sell the T/A 340 and fund the whole damn project paying a shop to do it.

[440dart]

[QUOTE=Kryp2nitE;978466][/FONT]

Agreed but a forged crank for the 360 is cheaper than the $$$ you are gonna drop on T/A Parts. ---- you could sell the T/A 340 and fund the whole damn project

Only difference is in the heads they are offset to allow for porting without going through the sides. Iam only 25 so i didnt grow up with this stuff but i think the blow has special webbing not sure on that but they did have 4bolt mains. So if you have a t/a block its probley the best block to have besides an aftermarket block.

[triggerfish]

Wow, a LOT of thoughtful help here & I do appreciate it. I did sell my real T/A project last year & the T/A block sonic tested really strong. They do have the beefier webbing & were designed for the installation of 4 bolt mains & that's why I thought of finding another one. I thought the 340 had a little larger bore than the 360 & just the stroke was different. I'm considering building another Challenger since I sold mine (Hemi 4 spd Chally) &
the turbo small block idea sounds pretty cool. Think I'll be soaking up a lot of info from this site. Thanks again for the info.

[turbovanman²]

318 and 340 shared the same stroke and different bore, 360 shared neither and had more bore and more stroke.


http://www.allpar.com/mopar/318.html

[turbovanman²]

Last time I checked, 360 blocks couldn't be bored to 340 size.

[Millerman340]

Actually the water should flow from the middle freeze plug in the block past the siamese exhaust ports through the heads then out the front & rear water passages in the heads by blocking the the front passage in the block. Also the 360 will take the 4.040 bore but you want to keep the cyl walls as thick as you can.

[Millerman340]

That T/A block is a stout piece & weighs about 20 lb more that the production piece with filled webbing in the pan & main area & provisions for a 4 bolt main. The hole is offset for the pushrod but has a standard port. The owner of a T/A / AAR will pay enough to step up to the 48* R3 Race block & W series heads...

[Turbo Joe]

thats definatly the best block you could use is the 340t/a or R code block like millerman said. the trans am block and the mopar performance Race block are both expencive to buy but you also get what you pay for.

[The Pope]

I would bake the block clean and use filler 2" deep on both sides. Then run all of your water by pass lines off the back of the engine, this is big to deal with heat. The stock by pass is in front and causes the coolant in the rear of the engine to be a lot hotter and boil in the heads. So running the heater and standard by pass off the back will help detonation too. The stock block is flexible and the filler strengthens the bores and mains. Of course main studs and girdles are nice to have also, caps fail when they twist and walk. the filler with the girdle helps with it.

Why on earth do you want to stroke it? Bigger stroke will turn boost into torque and will put a lot more twist on the block. You'll hook up better and have more RPM band with a stock stroke. Any HP loss can be returned with a couple PSI of boost.

If you want it to survive you can't run a carb. Many are tuning with them and it sucks. They get the job done fine with a drag car but the cost is also high. Just Megasquirt the car right off the bat and have a knock sensor boostoost fuel and spark curves. After you buy MP blocks and all the racing gear to beef up the block it is just cheaper to have FI and not detonate it in the first place. Looking how far Shadow is getting with the older 2.2 block should be an example.

JB the freeze plugs and run the MLS head gaskets with studs.

intercooler is the car, what fits, biggest that fits lol.

I am using a filled 360 TBI roller cam block with spacers to use the 340 crank. Basically making a TBI 340. This allows for the 480" roller hydraulic computer cam and no flat tappet cams again. A GREAT plan for Shelby Dak people. But mine has a 6-71 blower.

I've built in the past 318 turbos, a much better choice than a 340. 800 WHP isn't tough and way more than you'll use on the street by a long margin. Better cooling. Stronger block in stock form. Etc etc etc. Cramming CID in the block for "more power" is really senseless unless your aiming for 1500 HP. Then your building a drag car, not something you drive. The reason to aim 340 though is the bore for some more head flow, that is about it.

[Tempted]

Unless you want a 750hp rocket ship a stock 340 will handle a little boost. It makes enough torque not to worry about lag. What I love about turbocharging a V8 is that you can run a stock to very mild cam that will give you fantastic idle quality and drive-ability while still making more power than you can ever use on the street. A stock TBI SBC with a couple small turbos running low boost will put out over 500hp and be just as civil as it was before. If you keep your foot out of it it'll get about the same mileage too. Those are things you can never have with an N/A 500+hp V8.