360cu boosted

[Boostforlife]

Turbocharger<s> vs supercharger
which one guys
I am leaning towards turbo<s>
because turbos are more tunable

But I have other questions if you guys dont mind anwsering a few

1.> I am going to rebuild the motor with forged pistons and a high lift cam

what type of piston< as in dome top, flat top> what is the difference? and what company is best?

2.>I want to make this motor extremely fast but street driven<daily driver>

What is better, complete roller valvetrain or hydraulic or mechanical and what is the difference between these?

3.>I have a remanifactured 360 from advanced autoparts but I am tearing the motor back down so I am not sure what type of crank came oem on a 360 72-76, forged or cast? and if cast, can it handle boost?

4.> I would like to spray eventually< a small shot> so I was wondering what are some tricks or tips on how to make the bottom end "Bullet proof".

thanks guys
if to much than dont worry about it
any one know of pics or people with turbo mopars, let me know

[Boostforlife]

also, I want to fuel inject this car, do you guys know what would be the best system to go with, or should I use carb<s>

thanks for info guys

[1972roadrunner]

for turbo's, i believe it would be easier to go fuel injected... i'd rather have a supercharger though, cause i like big things stickin out of hoods....

the man you really wanna talk to is dewme5 (hope i spelled name right) maybe do a search on the board, you can find a lot and it you run across his name, go to his site. he had a twin turbo 360 with 6 speed in a cuda...which the block cracked in half...

good luck!

[dewme5]

don't remind me of the cracked block I still get teary eyed over it.

well, I really like the turbos, but sometimes they blow up engines. Blowers are really cool, but I like the stealthy approach. Superchargers are cool too, but come on slower then a turbo.

High lift is good, but you really need to avoid overlap if you are going to use a turbo.

Pistons.. well, you need to run a lower then normal compression ratio. for light boost 9psi, you are going to need around 8.5:1 compression, and more boost = lower CR. So, with running a low compression pistion, you are going to have to probably resort to flat or dished.

As with all motors, you have to make a choice. you can have a little power down low, and a lot up top.... or a good amount down low, and a little more up top. The way i want things, is easy cruising, almost a little lazy on the bottom end, and when i smack the pedal, all hell comes loose above 3000rpm. I just know ahead of time that at 1800, it's goign to be a dog.

Roller is better, but not so easy to do on an older block. if it came with hydraulic, it's goign to get expensive to convert it to roller lifters. roller rockers are a good step up also.

You can spray a motor with a turbo on it, but why? keep things simpler, run one power adder, and get all the power you want out of it. You can certainly get more power out of a turbo then your engine can handle, without the need for nitrous.

[1972roadrunner]

sorry bout the reminder...

[451Mopar]

Usually the Turbo cams are a bit milider so you don't blow off boost durring overlap. You should have the cam custom ground as most off the shelf cams are not designed for turbo applications. usually these will have wide lobe seperation angles which reduce overlap while increasing duration. Since the cams are not really wild, you don't have to go with a roller cam.
I would use a hydraulic cam rith 1.6:1 roller rocker arms for low maintance because once all the turbo plumbing is on the engine it might make it hard to do valve train adjustments.

You will want lower compression pistons, either flat toped or dished and probbably around 8.5:1 compression?

I'm not really up on blown engines so the the engine compression and cam specs will have to come from someone with more experiance than me. With a blown small block, the head gasket could be a problem, so you should have the engine "o" ringed and use copper head gaskets with ARP head studs.

[Boostforlife]

thanks a lot guys

what is the difference in quality and duty between domed and flattop pistons though

and also what is the difference between forged crank and polished and what are the benefits also

thanks for everthing guys

ben
fl

[1972roadrunner]

if it's from the same company, the quality will more than likely be the same.

as for the difference in domed or flat top, domed will be higher compression than the flat top. which, as these guys have stated, you don't want domed for forced induction, cause forced induction raises compression ratio's by forcing a lot of air in, and that can be hell on head gaskets... unless it's built to handle say around 15:1, or even higher...

if it were me, i'd get some blower pistons, which are generally dished (guessing, i've seen lots in my P.A.W book though), course, i'm savin for either a BDS 871, or Weiand 871. yes, it will be for street, i'll underdrive the bigger blower so it won't be spinning so fast, which will save heat and bearings...

good luck!

[justin terry]

Definetly need low comp. ratio. And forged pistons and crank. I have a 87 Buick GN. And it has dished JE pistons that give it 8to 1.
I have blown up the motor in it but it had TRW pistons and I think they are crap most Turbo buick guys will agree. Also need to brace the bottom end with either a Girdle or Billet steel main caps. I just got the main caps cuse I am only gonna be runnin high tens with my car so there wasnt a need to put a girdle on it. And buy the best head gaskets money can buy. For fuel injection you could go with GEN 7 DFI or F.A.S.T Fuel injection. Hope that helps

[Dr. Righteous]

Those cheap remans from Advance and Auto Zone are cheapo rebuilds made for dead stock applications.
I bought a set of reman 360 heads at Advance once. The heads were JUNK and leaked at the valve seals. The first set they gave me had 2 different casting numbers.

If I was you I would tear it down and MEASURE EVERYTHING. I would bet it has a crank in it that has been turned a dozen time and every journal is a different size.

[national]

Im also a 87 buick GN man...the turbos are awesome if all set up right & bottom end is strong enough to handle the torque they produce..I just wish someone made a nice header setup for it instead of turning headers upside down..might work but looks very low tek to me..id love to have a turbo under the hood of my 383 road runner but would want to be similar to the buick GN..maybe shorty headers & crossover pipe under the engine to join other header then mount turbo like the GN about same height as engine..be cool as heck if only someone out there had done it or maybe a neater looking way you know..but id go with a paxton type supercharger & fuel injection just for looks when hood is raised & will perform good also..get a good intercooler to match the supercharger also.
Brian

[awalsum]

I'm building a twin turbo 318 for my '69 Dart. I'm using ported and polished Edelbrock heads from the guys at Hensley, a hydraulic roller cam, aluminum roller rockers, H-beam rods, a forged 273 crank and definitely fuel injection! Go fuel injection if you wanna keep ya mill runnin'. Using a carb for turbo setups is almost inevitable damage.

A friend of mine is building my "board computer" He will be integrating the multipoint fuel injection with the ignition (retard etc.), electronic boost control on the turbo's, multi-level boost for street (6psi) or strip (12psi) with a scramble boost function (nitrous effect) a launch control and shift light all in one.

[68plyvaliant100]

This should give you a idea about turbocharging a mopar
Twin Turbo 440

[68plyvaliant100]

oh yea don't forget to use a BOV it saves a motor

[awalsum]

Thanks, looks awesome! I'm not sure on the BOV's yet, but am planning to use 'em.

[Woodchuck]

BOV saves the Turbo but realy does nothing for the motor at all.

[turbododge]

The BOV will do several things besides saving the turbo in case of a backfire or surge. It allows the turbo to be spooled up and putting out a decent air volume, even if the engine isn't using all the air, so that if you hit the throttle, you do not have to spool the turbo and accellerate all the air in the ducting. You will notice a big increase in throttle response at medium to high rpms with a BOV. The BOV is also open at idle and low speeds, even if the turbo is not putting out too much flow. At this point the engine is taking air in through the blowoff valve (that is why you should use an air cleaner on them). Having some low restriction air (not through the turbo) available to the engine at low, off idle, rpm can be very usefull in getting the car going untill you have enough rpm for boost.

Years ago these valves were called "response valves" rather than BOV because that was what was considered their biggest function.

[biggerhammer]

I see a lot of boosted cars blow head gaskets because they don't think o-ringing a block is worth it. lol, so I would recommend that you o-ring the block or get it cut for the wired head gaskets.

[Woodchuck]

The need for orings depends on the amount of boost. I run 10 psi to my 340 and probuce 634hp using a gasket designed for use on turbo and NOS sbd. The existing setup works up to 15psi with no gasket problems. The only problem is the turbo VE is pased at 12 psi and we make no more hp just more heat.

Now as for a BOV I still stand by the fact that the main benifit is turbo longevity in a LARGE turbo HIGH boost situation. But you are right turbododge they do alow the turbo to freewheel which decresses lag. But to quoat one of the best turbo bookes ever writen (21st Century Performance) " Almost ( but not quite) as useless as turbo timers are blow-off valves" .

But with that said I run a Turbonetics Godzzila BOV on the Challenger.

[BThompson]

Woodchuck could you give me the specs on your turbo 340(turbo size, manifolds used,etc)? I,m looking to turbo charge my 340.

[Woodchuck]

Sorry It took so long to reply. Been out of town

The Turbo is a 60-1 Turbonetics (1/2 a twin setup can you guess wats coming)
WG- Turbonetics Race Gate.
BOV- " Godzilla
Cam- Custom grind from Comp.
Heads- port matched pre emision J's with 2.02s & 1.60 w/72cc chambers
Headers- tight tuck shorties. Drivers side dumps down and back threw mandrel bends behinde the oil pan then joins the right sid and they both come up tothe front where the turbo sits and exits the turbo threw a 3" downpipe.
Pistons- TRW forged customs neting 8:1
Crank- Forged 70 340
Rods- Forged MPP
Bearings- All Clev 77
Hardware- Everything is bolted together with ARP studs
Intake- Torker 340 with Injector bosses welded in
TV- 1100cfm from Electromotive
Injection- Electromotive Tec 3
Converter- 3800 TCI
WP- Mezerie
Intercooler- Custom Sperco


We just spent 2 days on the dyno doing a full tune on the car. buy the time we were done the combo made. 398HP and 432ft/lbs .@ 8 lbs.

I am looking for a set of W2 long valves and a R4 block for the twin setup we a starting to put together. The single car will be a street toy. and the twin will be a monsor for the strip.

[BThompson]

Woodchuck I'm a little confused. Your post just above mine said 634HP at 10psi. Now your saying 398HP at 8psi. Is there that much differnce in 2psi?Thanks for the info.

[Woodchuck]

Wow I realy should proff read my posts before I post them. The 634 Should be 334 Sorry Never noticed that. But that was the HP @ 10 psi before last week. We spent a day on the dyno. and tuned in a ton. But ran out of time. Still havent done any pullls at 15 psi. Did all the tuning at 8 psi. The basic rule is 10 Hp for every lb of boost.

Sorry about the typo that would be a great # to have but I d beleve the engine would be in a ton of little pieces at over 600 hp to the wheels.

[turbododge]

Woodchuck: I surely don't want to get into any flaming match, so take this for what it is, only my opinion (and we all know about opinions).

Before you get into the next generation of turbo setup, take a close look at what you have, and what will improve things, and what may hurt things.

The heads and intake you have are very large for 400hp boosted, and if the cam matches them, you may not have enough turbo to get max output. Those heads will easily support 400hp normally aspirated and the intake more than that, so you could get an easy 600hp with 8 psi and in the rpm range that the heads and intake like to run (6500+). The big parts will kill the bottom end, and make the turbo slow to come in. If you have the turbo sized for lower rpm (5500?) then you may want to consider a smaller intake and heads. A good rule is to size the induction system and cam as if the engine were an N/A engine within the rpm range you are going to run.

I have run many versions of our twin turbo 340, with carbs and EFI, and am currently building a new engine for it (after over 15 years). This engine is going to be milder than the old one by quite a bit, and I think it will help a bunch. The 2.02 J heads will be replaced with 302 (closed chamber high swirl) heads with 1.88/1.6 valves that flow 180 cfm. The port volume will go from 185 to 125 so the velocity will go way up. The cam will go from a 210/220 to a 208/201 to better match the rpm and boost range. The intake will go from a M1 dual plane to a regular Performer, again for velocity reasons. The pistons will change from flattops to quench dish design to get faster burn, better detonation control, and allow for less total timing to improve efficiency. This will be a 15 psi/5500 rpm engine and should still do about 600 crank horsepower, but have a very wide torque curve, very good low end, and better fuel economy.

I have seen many turbo engines come and go over the years, and most are built too hot for what they are trying to do.

[Prochargedmopar]

Hey,
Somebody else here has been reading 21st Century turbo too. eh?

I'm only up to post 673 in the archives for blowthruturbo but I'm trying. sent money off today for the newsletter also.