Turbo manifold

[tealcherokee]

i decided to put this here, instead where everyone looks, to try to keep it useful info free:

heres what im thinking

http://ryan.tehbaron.com/images/street/turbomani.jpg

big pic, but thats what microsoft gave us scroll bars for.

anyway, its going to end up mounting the turbo through the hood, but, other than that, any down falls?

[5-90]

Any particular reason you can't do away with the inlet elbow, and have the turbo below the hood?

I'd also consider a pair of smaller turbos - mount the two turbos between cylinders #2 & #3, and #4 and #5... That would give you more boost at lower crankshaft speeds, and even out air distribution as well...

5-90

[tealcherokee]

Any particular reason you can't do away with the inlet elbow, and have the turbo below the hood?

I'd also consider a pair of smaller turbos - mount the two turbos between cylinders #2 & #3, and #4 and #5... That would give you more boost at lower crankshaft speeds, and even out air distribution as well...

5-90

im sure the TT set up is possible, but this turbo was free, and new.

and theres NO way to fit this thing under the hood, its god aweful huge

http://tehbaron.com/ryan/images/street/DSCF0833.jpg

[5-90]

Figures. That was the other reason for the twin turbo setup - compactness, and greater flexibility in mounting.

If you do decide to do the manifold, I'd appreciate it if you'd share the layout of the mounting flange. I've been thinking of a Helmholtz-tuned intake for the 4.0, and there's no need to reinvent the wheel for mounting it up (leaving me free to concentrate on runner design...)

Granted, with the low RPMs we run with, the runners will probably be ungawdly long - something I'll have to finagle...

5-90

[DirtyMJ]

Why 90* 'em down right off the head? Isn't that asking for the intake manifold to be awefully close to the exhaust? You're going to have some nasty heat soaking as is...



Although, I guess it depends how your exhaust is built to.

[5-90]

The problem with turbos is that the exhaust manifold collector should be fairly close to the intake - so the turbo has somewhat less work to do. Since the turbo isn't a fixed displacement compressor, it needs some help.

If you're going to the trouble, you may as well fab up an intake AND and exhaust manifold (I'd like flange dims for both, please!) and you can then work a heat shield between them - which is considerably less of a problem than fabbing up the manifolds to start with.

Granted, with a little judicious re-arrangement, it would probably be possible to work the intake to come straight off the head (or maybe upwards just slightly,) to clear the exhaust manifold and to allow for more room for a heat shield. Since turbo exhaust manifolds aren't as picky as regulars, you are actually freed up just slightly in that regard.

This should make for an interesting thought experiment on my part - just for fun...

5-90

[badron]

At what RPM range are you looking for what boost? From here that looks like a big compressor for a I6 at least for most offing needs.

[tealcherokee]

At what RPM range are you looking for what boost? From here that looks like a big compressor for a I6 at least for most offing needs.

that turbo will spool at around 2400...

and its going on a stroker :D

[Michaelarchangelo]

what are the specs on the turbo?

Also, I think you are going to have some wicked backpressure with collecting exhaust gases with where the outlet elbow is.

[tealcherokee]

what are the specs on the turbo?

Also, I think you are going to have some wicked backpressure with collecting exhaust gases with where the outlet elbow is.

garrett gt4088, compressor is a .72A/R and i think the turbine is 1.19A/R (could be 1.34, i dont remember)

i think theres more on garretts site

[jeepdude10000]

i was thinking about putting in a small turbo in the passenger side of the engine, that way i would not have to mod the header, and the small turbo woold spool up faster.

[MogifiedXJ]

The problem with turbos is that the exhaust manifold collector should be fairly close to the intake - so the turbo has somewhat less work to do. Since the turbo isn't a fixed displacement compressor, it needs some help.

If you're going to the trouble, you may as well fab up an intake AND and exhaust manifold (I'd like flange dims for both, please!) and you can then work a heat shield between them - which is considerably less of a problem than fabbing up the manifolds to start with.

Granted, with a little judicious re-arrangement, it would probably be possible to work the intake to come straight off the head (or maybe upwards just slightly,) to clear the exhaust manifold and to allow for more room for a heat shield. Since turbo exhaust manifolds aren't as picky as regulars, you are actually freed up just slightly in that regard.

This should make for an interesting thought experiment on my part - just for fun...

5-90

Or you could find someone with a cnc mill and design a hemispherical, 24v, dual over head cam, cross-flow head for the 4.0l. That way you could have the intake on one side and the exhaust on the opposite. Now that is an interesting thought experiment...:D

[tealcherokee]

Or you could find someone with a cnc mill and design a hemispherical, 24v, dual over head cam, cross-flow head for the 4.0l. That way you could have the intake on one side and the exhaust on the opposite. Now that is an interesting thought experiment...:D

ill test one for you!!

[tealcherokee]

i was thinking about putting in a small turbo in the passenger side of the engine, that way i would not have to mod the header, and the small turbo woold spool up faster.

505 already makes that piece of shit.

this IS the correct size single turbo for a 4.5L stroker, and its pretty good for a 4.0L also.

[5-90]

505 already makes that piece of shit.

this IS the correct size single turbo for a 4.5L stroker, and its pretty good for a 4.0L also.

For a SINGLE turbo, you're right (off the top of my noggin.) However, spooling right about 2400 is a little low for what we're after - you'd want to see it spooling a little lower (say, 1800-2000rpm) so you'd get peak boost right around the torque plateau - which is another reason to go with two. Granted, you'd have to design a new header as well (split the cylinders into groups of three,) but you'd probably have to do that anyhow.

I've also been kicking around ideas for a crossdraft head for the 4.0 as well - just on account of 'cause. It would be too much to make it work as an OHC head right off, but that might come later...

5-90

[MogifiedXJ]

I've also been kicking around ideas for a crossdraft head for the 4.0 as well - just on account of 'cause. It would be too much to make it work as an OHC head right off, but that might come later...

5-90

Nothing worth while comes easy...However, I don't think it would be that hard to do, and just think of the power potential. Twin turboed, hemi-head, 4.7L strocker, and what the hell go ahead and put roller bearings through out the entire engine too. (Homer simpson voice) Ughlllllllllllll (End homer simpson voice). Once someone got a proto type built I don't think they would have any trouble selling them for what ever price they wanted to ask.

[5-90]

Which is why I'm trying to finish school, and why I'm studying Mechanical Engineering and CNC/Tool & Die Maker (at least. I've had to change some plans, but I'm pretty much always in a "state of flux" anyhow...)

5-90

[goodburbon]

Another thing of note is the length of the log manifold you have designed. The expansion of such a long straight tube would almost surely force cracking at the #1 or #6 tie-ins.

Brandon

[MogifiedXJ]

Another thing of note is the length of the log manifold you have designed. The expansion of such a long straight tube would almost surely force cracking at the #1 or #6 tie-ins.

Brandon
It looks just like a cummins diesel manifold to me...

[goodburbon]

Durability and longevity all depend on the material he uses. I'm not saying the design won't work, but that special consideration should be given when choosing material.

Edit: I really should have spelled that out in my first response. I didn't mean it WILL crack. My fault.

[tealcherokee]

Durability and longevity all depend on the material he uses. I'm not saying the design won't work, but that special consideration should be given when choosing material.

Edit: I really should have spelled that out in my first response. I didn't mean it WILL crack. My fault.

im making it out of .88 wall HREW

[Berubeny]

You need to fab a turbo support off the block. My Turbo dodge has one that helps hold the weight of the turbo so the manifold doesn't crack. Is this for offroading or speed? If its for offroading a smaller turbo would spool fast. My stock turbo was a tiny mitsu started spooling at 1800 or so. Now the garrett
I have doesn't start spooling until 2500-2700 rpms but builds boost all the way to 6200rpms.

[Michaelarchangelo]

garrett gt4088, compressor is a .72A/R and i think the turbine is 1.19A/R (could be 1.34, i dont remember)

i think theres more on garretts site



That is a damn big turbo.

[MogifiedXJ]

That is a damn big turbo.
That's what I was thinking. I wonder what his compression ratio is right now, naturaly aspirated???

[tealcherokee]

That's what I was thinking. I wonder what his compression ratio is right now, naturaly aspirated???

9.8:1, going to be 13.8:1 under full boost (6psi). everyone thinks its way to high, but for such low boost, its really not.

[MogifiedXJ]

9.8:1, going to be 13.8:1 under full boost (6psi). everyone thinks its way to high, but for such low boost, its really not.

I didn't realize you were running such a low boost, you're still going to move a large volume of air with that big ass turbo though. Throw in some dish pistons, reinforce the bottom end, O-ring the head and block, and crank the psi up on that thing. By the way are you running studs on the head???

[tealcherokee]

I didn't realize you were running such a low boost, you're still going to move a large volume of air with that big ass turbo though. Throw in some dish pistons, reinforce the bottom end, O-ring the head and block, and crank the psi up on that thing. By the way are you running studs on the head???

I'm building a 5.1L stroker, thats going to be running the same size turbo, w/ a clifford head, at about 15psi, looking for 600whp.

this is just my test motor and jeep.

I'm running grade 9 bolts for the head, i like them better than studs

[MogifiedXJ]

I'm building a 5.1L stroker, thats going to be running the same size turbo, w/ a clifford head, at about 15psi, looking for 600whp.

this is just my test motor and jeep.

I'm running grade 9 bolts for the head, i like them better than studs
That sounds impressive. Have you checked out hescos new aluminum head? I don't know how it would do with 15psi under it though. Why a clifford head? I'm not sure I've seen one of those...

[tealcherokee]

lol, sorry man, hesco head, clifford carb intake

ditchin EFI

[MogifiedXJ]

lol, sorry man, hesco head, clifford carb intake

ditchin EFI
Three two-barrel webers would look nice hangin of the side of the block. It would be easy to fab up an intake for them. I don't know how they like the boost though.

[tealcherokee]

just 1 4bbl

hey, do you have an AIM, if so

AnXjOnTheRocks

[MogifiedXJ]

just 1 4bbl

hey, do you have an AIM, if so

AnXjOnTheRocks
No man I don't...I guess I'm fallin behind the times.

[zthang43]

9.8:1, going to be 13.8:1 under full boost (6psi). everyone thinks its way to high, but for such low boost, its really not.

SPOBI

Sorry, but I have to chime in here, because it always bugs me when people talk about having a different compression ratio under boost. BOOST DOES NOT CHANGE COMPRESSION RATIO!
Compression ratio is calculated based on cylinder volume at BDC vs. cylinder volume at TDC. (Bore, stroke, cylinder head volume, and piston dish volume are used to figure this out.) None of these things change under boost. Compression ratio is a function of volume, boost is pressure; they are different.

[5-90]

He may be referring to "effective compression" - which is a function of boost. I don't recall how it works (and I don't have the book handy at the moment, or I'd explain it,) but it is a real phenomenon.

However, the "basic" or "geometric" CR of the engine does not change, unless you change something within the acting cylinder (head dish dims, piston dish/dome, bore size, stroke.)

Effective compression ratio, however, is a function of several other things. For instance, you can build an engine combo with a "basic" or "geometric" CR of 9.0:1, but that can be changed (always to soemthing lower than 9.0:1) by changing camshafts, for instance. The key there is the timing of the "Intake Valve Closing" event. I believe I cover this in my book - but I'll add it as an update if I haven't (gotta finish the Tech Archive updates first...)

5-90

[OT]

Effective compression ratio calculator (http://www.rbracing-rsr.com/compression.htm)

[5-90]

Thanks. Even if that site doesn't explain the idea, it illustrates it (and correcting for altitude is a nice touch...)

5-90

[ArcticXJ]

I'm keeping an eye on this one. You cats are getting pretty wild with the forced induction. How much of an over-bore are you using to achieve the 5.1 displacement? 258 rotating assebly or something totally one off? If those cylinder walls are getting as thin as I'd assume they are, then that 600 whp (which would translate to over 700 at the fly) and 15psi is really going to be testing the structural limits of that block.

Nonetheless, I'd really, really, really love to watch/listen to a dyno pull when you get around to it.

[OT]

Sorry, Jon.
Here ya go....
http://www.motorsportsdigest.com/tech/forced2.htm

[MogifiedXJ]

boost psi / 14.7
+ 1
x motor compression
= effective compression.

[5-90]

Sorry, Jon.
Here ya go....
http://www.motorsportsdigest.com/tech/forced2.htm

Oh - no trouble understanding here. I've probably got the theory in a couple of books (remind me to send my my "list of references" sometime...) I just wanted to see it explained for everyone else...

As far as "high-boost" engines, you're probably going to be better off with a RENIX block (I've had the opportunity to "sonic check" RENIX/GEN-I HO/GEN-II HO, and I'll have to see what I did with those figures...) and the casting walls got progressively thinner. I remember hearing that Mike Parrish (formerly of Accurate Machine) had bored a RENIX block out to 4.000", and the RENIX block I checked would still have had something like .175" of cylinder wall all around - with the "accepted minimum" for boring a block being .100". Intereting to think that a RENIX block might be able to handle what would be oversize SBChevvy pistons, no?

I'm also hoping to get a little more out of Flatlander Racing on their stroked 258 crank - 4.145" stroke! Just imagine what we could do with that... If anyone else would be looking for information, please write requests and email them to me, and I'll include them with the next letter I write to them (once I get a few other things done - which will allow all of you to formulate your letters...) Previous communications with them said "that it would only work in the AMC258I6, since that's what we developed it for," but if it fits the 258, I'm sure it can be made to fit a 242 - and 4.000" x 4.145" = ~312cid! I would be honoured to design other components (like pistons, and possibly cams) that would make something like that well-behaved at cruise, but a torque MONSTER off-idle! So, the more help I get from you in terms of requests, the more information I might be able to develop (and share!) from them.

5-90

[ifoundastick]

One question that ponders in my mind about this whole setup is your still going to have to deal with a carburetor. I mean yeah your going to have a alot of horsepower but if your going to be really wheeling that beast aren't you going to have to deal with the carb flooding and the troubles that comes with carburated engine?

[MogifiedXJ]

One question that ponders in my mind about this whole setup is your still going to have to deal with a carburetor. I mean yeah your going to have a alot of horsepower but if your going to be really wheeling that beast aren't you going to have to deal with the carb flooding and the troubles that comes with carburated engine?
From what I gather it's going to be a "street" jeep.

http://www.naxja.org/forum/showthread.php?t=90989

[zthang43]

He may be referring to "effective compression" - which is a function of boost. I don't recall how it works (and I don't have the book handy at the moment, or I'd explain it,) but it is a real phenomenon.

However, the "basic" or "geometric" CR of the engine does not change, unless you change something within the acting cylinder (head dish dims, piston dish/dome, bore size, stroke.)

Effective compression ratio, however, is a function of several other things. For instance, you can build an engine combo with a "basic" or "geometric" CR of 9.0:1, but that can be changed (always to soemthing lower than 9.0:1) by changing camshafts, for instance. The key there is the timing of the "Intake Valve Closing" event. I believe I cover this in my book - but I'll add it as an update if I haven't (gotta finish the Tech Archive updates first...)

5-90

I think you are talking about Volumetric Efficiency, which is a known and accepted term in the automotive industry. The idea of "Effective compression", while I understand what you mean, is a bit skewed and misleading. 13.8:1 "effective compression" under 6psi boost does not behave the same as a real 13.8:1 compression ratio. That high compression ratio would destroy most engines very quickly running on pump gas, but the same "effective compression ratio" achieved by running 6psi boost should be perfectly safe in a properly built engine running on cheap pump gas.

The difference is that the forced induction motor is forcing a larger volume of the air/fuel mixture in the cylinder, as opposed to a NA motor squeezing a smaller volume to get a high compression ratio. Theoretical maximum Volumetric Efficiency for any NA motor is 1 (although with proper tuning of the intake pulses a slightly higher VE can be achieved); but a forced induction motor can have a VE greater than 1 (or 100%, .9 would be 90%). This is still related not only to boost but to cam profiles, head geometry, valve sizes, intake configuration, etc, etc, so even a boosted motor that is poorly designed can have a VE less than 1.

Hopefully this explains why the concept of "effective compression" is flawed; sure, it's an easy calculation that sounds good, but it doesn't actually make sense unless you account for the Volumetric Efficiency of the engine without boost.

Sorry, I didn't mean to sidetrack this thread; it just bugs me when people throw around artificial compression ratios that are completely bogus, just because they think it sounds cool, like "yeah, i'm running 15psi boost so i've got 18:1 compression ratio". A motor with that kind of compression ratio could run on diesel fuel, not gasoline.

[5-90]

I think you are talking about Volumetric Efficiency, which is a known and accepted term in the automotive industry. The idea of "Effective compression", while I understand what you mean, is a bit skewed and misleading. 13.8:1 "effective compression" under 6psi boost does not behave the same as a real 13.8:1 compression ratio. That high compression ratio would destroy most engines very quickly running on pump gas, but the same "effective compression ratio" achieved by running 6psi boost should be perfectly safe in a properly built engine running on cheap pump gas.

The difference is that the forced induction motor is forcing a larger volume of the air/fuel mixture in the cylinder, as opposed to a NA motor squeezing a smaller volume to get a high compression ratio. Theoretical maximum Volumetric Efficiency for any NA motor is 1 (although with proper tuning of the intake pulses a slightly higher VE can be achieved); but a forced induction motor can have a VE greater than 1 (or 100%, .9 would be 90%). This is still related not only to boost but to cam profiles, head geometry, valve sizes, intake configuration, etc, etc, so even a boosted motor that is poorly designed can have a VE less than 1.

Hopefully this explains why the concept of "effective compression" is flawed; sure, it's an easy calculation that sounds good, but it doesn't actually make sense unless you account for the Volumetric Efficiency of the engine without boost.

Sorry, I didn't mean to sidetrack this thread; it just bugs me when people throw around artificial compression ratios that are completely bogus, just because they think it sounds cool, like "yeah, i'm running 15psi boost so i've got 18:1 compression ratio". A motor with that kind of compression ratio could run on diesel fuel, not gasoline.


"Effective CR" is more applicable to cam changes than boost levels, but it's not the same thing as VE.

"Volumetric Efficiency" is the percentage of theoretical air moved per revolution versus air actually moved. Assuming your engine is supposed to move 400CFM, having 80% VE at one point means that your engine will move 320CFM.

"Effective Compression Ratio," as it is commonly used, is the ratio between the space left at TDC versus the space left in the cylinder at the time the intake valve closes. Closing the valve earlier (closer to BDC) will increase the ECR, and closing it later (farther from BDC) will decrease it. However, ECR, in this case, will NOT be higher than the theoretical CR. "Effective" compression ratio is more like "actual" compression ratio, in this case.

"Effective" compression, in the case of boost, relates to the pressure of the compressed gas mix at TDC versus atmospheric pressure, which is why ECR for boosted engines damn sure CAN be higher than the theoretical CR. However, I'm still explaining this rather poorly, but I haven't gone through my notes. I probably did a better job in my book, but I didn't write that off the top of my head...

5-90

[zthang43]

"Effective CR" is more applicable to cam changes than boost levels, but it's not the same thing as VE.

"Volumetric Efficiency" is the percentage of theoretical air moved per revolution versus air actually moved. Assuming your engine is supposed to move 400CFM, having 80% VE at one point means that your engine will move 320CFM.

"Effective Compression Ratio," as it is commonly used, is the ratio between the space left at TDC versus the space left in the cylinder at the time the intake valve closes. Closing the valve earlier (closer to BDC) will increase the ECR, and closing it later (farther from BDC) will decrease it. However, ECR, in this case, will NOT be higher than the theoretical CR. "Effective" compression ratio is more like "actual" compression ratio, in this case.

"Effective" compression, in the case of boost, relates to the pressure of the compressed gas mix at TDC versus atmospheric pressure, which is why ECR for boosted engines damn sure CAN be higher than the theoretical CR. However, I'm still explaining this rather poorly, but I haven't gone through my notes. I probably did a better job in my book, but I didn't write that off the top of my head...

5-90

I hear ya, but Effective compression ratio in the case of boost is still a misleading and completely useless calculation that I hear used by people who think it sounds cool and don't understand what they are talking about.

You can't equate 13.8:1 "effective compression ratio" under boost to 13.8:1 actual compression ratio in a NA motor. The combustion process would be much faster, and peak at much higher pressure (with detonation a likely result), than the boosted motor, which will have a combustion process that lasts longer with lower pressure and produces more power.

[tealcherokee]

Holy crap my thread took off.

for the 5.1 im going to be running hescos alum block if it ever comes out

as far as the evvective compression, you guys got it covered

[5-90]

I hear ya, but Effective compression ratio in the case of boost is still a misleading and completely useless calculation that I hear used by people who think it sounds cool and don't understand what they are talking about.

You can't equate 13.8:1 "effective compression ratio" under boost to 13.8:1 actual compression ratio in a NA motor. The combustion process would be much faster, and peak at much higher pressure (with detonation a likely result), than the boosted motor, which will have a combustion process that lasts longer with lower pressure and produces more power.

True, very true. "Effective compression" due to cam changes is a little more realistic - there are too many variables (most notably altitude and ambient temperature) to go into calculating "effective compression" due to boost.

5-90

[DirtyMJ]

Teal, gotta ask about your intended ignition system with a carb...


What exactly are you doing? How will you set your timing? (Don't need numbers, I need process) Or are you going to use some fancy computer controlled setup which allows you to do that in real time and blah blah blah...?


I have a similar project, which is nothing alike other than it involves ditching the Renix FI. The only hitch I have right now is that there's no timing marks on my harmonic balancer, and I'm having no luck finding an ideal solution...

[MogifiedXJ]

You might want to consider adapting something like an old hilborn mechanical fuel injection to your turbo setup instead of a carb. It's about the simpliest injection I can think of. Everythings mechanical even the fuel pump which is belt driven of the engine.

[DirtyMJ]

How about we convince teal to run propane? 107 octane, very clean fuel, and making a draw through setup is VERY easy. Having the mixer after the turbo gets tricky though, but I know there is a system out there for it.



Other than propane isn't big south of the border.

[tealcherokee]

theres 2 ways to go carbed. 1, msd set up. 2, stock 258 distributor

so the cheap way, is the 258 distributor

[DirtyMJ]

theres 2 ways to go carbed. 1, msd set up. 2, stock 258 distributor

so the cheap way, is the 258 distributor


Well, I've got a GM HEI dist/etc from a 250 I6. Basically bolts in. However, I'm a little bit weirded out as the harmonic balancer has no timing marks, and I'm not even sure I can put timing tape on it.


I'm looking into it.

[tealcherokee]

Well, I've got a GM HEI dist/etc from a 250 I6. Basically bolts in. However, I'm a little bit weirded out as the harmonic balancer has no timing marks, and I'm not even sure I can put timing tape on it.


I'm looking into it.

it does have a mark, its just hard to see

[tealcherokee]

heres a little taste of what im working on

http://ryan.tehbaron.com/header.jpg

[Michaelarchangelo]

Where are you going to mount the turbo in that setup? Will It clear the intake? I like the look of this one better, but you are going to need to collect the gases together before you reach the turbp.

[tealcherokee]

Where are you going to mount the turbo in that setup? Will It clear the intake? I like the look of this one better, but you are going to need to collect the gases together before you reach the turbp.

as i said, its just the start.

there will be a collector of some sort on the end

[MogifiedXJ]

What software are you using to design this on? I've got some copies of pro-e if you don't already have it.

[tealcherokee]

What software are you using to design this on? I've got some copies of pro-e if you don't already have it.

i use auto cad, ive been using it since i was about 13 lol, ive never heard of pro-e, i dont even look at anything else im so fimiliar w/ cad

[MogifiedXJ]

i use auto cad, ive been using it since i was about 13 lol, ive never heard of pro-e, i dont even look at anything else im so fimiliar w/ cad
I used to use autocrash too before I learned Pro-E. It's a world of difference...It takes a little while to get the basics down but its truly an amazing software. Are use using autocad inventor or just autocad to do your drawings?

[tealcherokee]

just autocad, good old autocad, version 2007, but on the old style setting

[MogifiedXJ]

just autocad, good old autocad, version 2007, but on the old style setting
Oh man doing 3d in autocad really sucks. Both of those manifolds in Pro-e would have taken 5 minutes max...plus parts can be machined from pro-e straight to a cnc machine.

[tealcherokee]

Oh man doing 3d in autocad really sucks. Both of those manifolds in Pro-e would have taken 5 minutes max...plus parts can be machined from pro-e straight to a cnc machine.

yeah, i dunno, i like auto cad, the longest part was making it fit, using only 90* bends

http://ryan.tehbaron.com/images/street/tubeheader.gif