a new "blow-through" build..

johns3524

Well-known member
Hi there guys, I am new here as you can determine. I've been a lurker for a couple years or so while building a DD powered by the infamous 300-6. My signature bears it's credentials and I built it myself. I was around when "Corsa" 150's and then 180's were around, and built a few DD's while working on a restored "65 180 had to be sold due to "life" and financial issues that were involved. (It died hard though, I towed it to Alaska along with all of the matching serial numbered correct parts, and it was drive-able with a 2-carb 110 at the time.)

Any-who, I get turbos, and I get why "blow-thru" carb'ed at lower pressures (up to 10 or so) may be the best choice for me to shoot for given the following parameters.:

stock crank, rods, cam (with a Cloyes metal set),.060 over block, (pistons are at this point up for discussion, although I like H519p hypers.)

This will be the block. Whether I will turbo or not It will be with me for a while as stated.

Heads: I can use a 90" EFI, or an 86, or 79 carb'ed head.

So, if I use an EFI head (which I prefer), what about using say (2) head-gaskets, lowering the pressure to allow for a safe (fairly experimental) head pressure to allow for up to 10 psi? (If I don't turbo it, I can remove 1 gasket and continue to use the block as a viable carb'ed naturally aspirated block).

This will all be going thru a CARB. I can use an Autolite or Holley, AND If Holley, I MAY be using a leaning device newly discovered that will allow me to adjust a HOLLEY carb from Idle cutoff-100% rich. (adjusted in-cab via a vernier mixture control). (managed by EGT input)

I believe I will use EFI exhaust manifolds, fabbing up a stainless turbo-mount-supporting style header pipe. Using a turbo solves many problems allowing for use of a cummins-style 3" out-flange, making the exhaust install very manageable. I WILL incorporate and EGT manual gauge style overall temp monitoring situation either pre-turbo or post...of course we CAN add an inter-cooler, and no doubt, WILL in time, allowing for higher limits of boost.

This is a long post and thank you for our patience.

May I say, that overall insane POWER is not my main objective. I hope to achieve a -low-boost, air-supplemented type of install suing a carb, and manual adjust-ability using an EGT to monitor overall health of the motor..(basically pistons) of course as testing proceeds, with satisfactory results, I CAN dial in more boost.

I GET how to do the carb hat install, and have the necessary tools and info to seal up the carb...

any "don't do it" input?...I have three engines or so available for testing..I WILL be shooting for low rpm spooling and the ability to "work" this 300-6 to a better potential under 2500-3000 rpm..so turbo choice is also a part of that equation, I get that..open to suggestions there.

On Edit I forgot to mention that I WILL use a DSII ignition probably initially, and am able to modify my own spark curve if need be. I am familiar with catch-can's for for breathing assistance, although at the RPM's I plan to operate at I don't see it as a potential problem.
 
Don't do .060" over bore.
For turbo use you want as much cylinder wall thickness as possible.
Displacement is not as important as block integrity.

Sonic check the block for cylinder wall thickness and core shift.
If you have more than one block to choose from then check them all and use the best one.
Then only bore enough to clean up the cylinder walls.

No double head gaskets. Stacked head gaskets will blow out.
If a person was to go that route then they would use a single thin head gasket or a single thicker head gasket.

If you are going to use an intercooler and 10 psi of max boost, then the engine can be set up one time for both NA and/or boost.
Your looking for a cam and compression ratio combination for maximum torque from idle to 3000 rpm.
Those combinations general dictate a static compression ratio at 8.5 or less.

To minimize detonation, piston to head clearance should be around .040" so no thick head gaskets.
The piston needs to be near zero deck to accomplish proper clearance.
If you use the EFI head that puts around 34cc in the piston dish.
If you use the carb head then the piston has around a 24 cc dish.

You can do an inverse dome piston that mirrors the combustion chamber or a Spherical dish that centers the down force over the center of the piston pin.

I would use the early stock rods that do not have the oiling holes in the big end.

Do you plan on using the stock cam?
 
pmuller9":2vf33pud said:
Don't do .060" over bore.
For turbo use you want as much cylinder wall thickness as possible.
Displacement is not as important as block integrity.Dully noted

Sonic check the block for cylinder wall thickness and core shift. I'm not sure I can get that done locally, but I'll look into it..and make a plan
If you have more than one block to choose from then check them all and use the best one. good point and good info to have
Then only bore enough to clean up the cylinder walls. I have 3 blocks, 1 standard, 1=.030, 1=060

No double head gaskets. Stacked head gaskets will blow out.
If a person was to go that route then they would use a single thin head gasket or a single thicker head gasket. Noted

If you are going to use an intercooler and 10 psi of max boost, then the engine can be set up one time for both NA and/or boost.
Your looking for a cam and compression ratio combination for maximum torque from idle to 3000 rpm.
Those combinations general dictate a static compression ratio at 8.5 or less. Noted, I was hoping for about 8.0+

To minimize detonation, piston to head clearance should be around .040" so no thick head gaskets.
The piston needs to be near zero deck to accomplish proper clearance.
If you use the EFI head that puts around 34cc in the piston dish.
If you use the carb head then the piston has around a 24 cc dish.
You can do an inverse dome piston that mirrors the combustion chamber or a Spherical dish that centers the down force over the center of the piston pin. I need to pencil on this some more for sure..noted

I would use the early stock rods that do not have the oiling holes in the big end. good point

Do you plan on using the stock cam?

I have at least 1 good stock cam so it would be my choice at this point. All good points to consider and I appreciate the input. I am juggling my projects around in my little shop this next week, and I'll begin to look at that standard bore block first. It is still all assembled at this time..so I'll know more in a week or two about that.

Thanks for the overall look at the plan. It sounds like I should focus on what piston to use first, based on an EFI head I guess. I haven't forgotten about checking the pistons out that you are using.

I'll be looking for a turbo that will come in as early as possible as well. From what I remember a small IHI did a pretty good job, but I need to look at all the options. The turbo choice flange needs will determine my approach to the exhaust config too, so choosing wisely and early will will make That an easier process.
It may take some time to build this up, but since I'm going to have the basic long block built and running in the truck,( which will more than likely be a c6 install), I'll be able to add what I need as I go. Having a solid, broken-in motor is my idea of a platform. We'll be in touch..and reading..always reading...things change.
 
why is it that you want to run the EFI head? general consensus seems to be that the carb head will flow a bit better, and it would make achieving the lower CR a little easier I think. but fast burn feature of the EFI head, if not disturbed could work for you.
 
country fried 6":2lhrdqkf said:
why is it that you want to run the EFI head? general consensus seems to be that the carb head will flow a bit better, and it would make achieving the lower CR a little easier I think. but fast burn feature of the EFI head, if not disturbed could work for you.

Thanks for asking, I actually have been wanting to buy a new casting while available from Engine-Quest anyway that supposedly has a few thicker areas in the casting. I'm not sure if they are really any better, or even as good as OEM, but having tried one that I'm now using on my signature Bronco, I like it. I like the extra exhaust mount holes for hanging the EFI manifolds but that is a side "benefit".
I mainly wanted a new casting and they are offered with hardened seats. I will merely smooth out any casting roughness but not make any major changes. In my growing interest in these 300's I have found some EFI heads cracked beyond use, and it has become important for me at least in my perception that having a spare head, may not be a bad idea for an engine that is not longer produced. (Using the philosophy--life is in the head) There doesn't seem to be a lot of aftermarket support for these motors either, at least not like the typical SBF or SBC, so again..a spare head.

I will focus on the pistons for reaching the compression ratio I want even if I have to have them custom done I think. Hopefully the "as-I-think" process will help the best ideas to come to the surface as the project matures...
 
johns3524":3elnt9p4 said:
I actually have been wanting to buy a new casting while available from Engine-Quest anyway that supposedly has a few thicker areas in the casting. I'm not sure if they are really any better, or even as good as OEM, but having tried one that I'm now using on my signature Bronco, I like it. I like the extra exhaust mount holes for hanging the EFI manifolds but that is a side "benefit".
I mainly wanted a new casting and they are offered with hardened seats. I will merely smooth out any casting roughness but not make any major changes. In my growing interest in these 300's I have found some EFI heads cracked beyond use, and it has become important for me at least in my perception that having a spare head, may not be a bad idea for an engine that is not longer produced. (Using the philosophy--life is in the head) There doesn't seem to be a lot of aftermarket support for these motors either, at least not like the typical SBF or SBC, so again..a spare head.

I will focus on the pistons for reaching the compression ratio I want even if I have to have them custom done I think. Hopefully the "as-I-think" process will help the best ideas to come to the surface as the project matures...

I looked at the Engine-Quest heads and can see why you want the new casting. Having hardened valve seats is reason alone and with the extra deck material and slightly improved ports is just another plus.

Your project is different from the norm in that the main focus is on how low in rpm can torque be made with a power adder rather than the quest for higher rpm horsepower.
The head needs to have high velocity port flow at low engine rpm which means the stock port size is fine.
The casting around the valve guides in the bowl area could be re-shaped for better flow and just a clean-up in the ports.
The combustion chambers need to be polished and all sharp edges rounded.

I always have the valve seat run-out checked along with the valve guide clearance. The run-out needs to be within .002" for valve guide longevity.

Turbocharger:
I'm figuring a working rpm up to 3500 rpm with a 4000 rpm max. Correct me if I'm wrong.
Max boost is 10 psi.
The stock head with some massaging should allow an engine Volumetric Efficiency of 80% at the low rpm range.
Figure 50% air to air intercooler efficiency.

Using those figures the turbo needs to supply 27 lbs/min of air at 3500 rpm at a compression ratio of 1.76 and a max of 31 lbs/min at 4000 rpm.
This falls in the range of a 47 mm turbo. I believe this also fits the IHI RHF55 turbo that you mentioned.

Using a small .60-.64 A/R turbine housing you should be able to get max boost by 2000 rpm.
The engine will produce 420 ft.lbs of torque from 2000 to 3000 rpm.

Air temps out of the turbo will be around 200 degrees and around 135 out of the intercooler at 50% efficiency.
 
pmuller9":3dvm872b said:
johns3524":3dvm872b said:
I actually have been wanting to buy a new casting while available from Engine-Quest anyway that supposedly has a few thicker areas in the casting. I'm not sure if they are really any better, or even as good as OEM, but having tried one that I'm now using on my signature Bronco, I like it. ....... done I think. Hopefully the "as-I-think" process will help the best ideas to come to the surface as the project matures...

I looked at the Engine-Quest heads and can see why you want the new casting. Having hardened valve seats is reason alone and with the extra deck material and slightly improved ports is just another plus.

Your project is different from the norm in that the main focus is on how low in rpm can torque be made with a power adder rather than the quest for higher rpm horsepower.
The head needs to have high velocity port flow at low engine rpm which means the stock port size is fine.
The casting around the valve guides in the bowl area could be re-shaped for better flow and just a clean-up in the ports.
The combustion chambers need to be polished and all sharp edges rounded.

I always have the valve seat run-out checked along with the valve guide clearance. The run-out needs to be within .002" for valve guide longevity.

Turbocharger:
I'm figuring a working rpm up to 3500 rpm with a 4000 rpm max. Correct me if I'm wrong.
Max boost is 10 psi.
The stock head with some massaging should allow an engine Volumetric Efficiency of 80% at the low rpm range.
Figure 50% air to air intercooler efficiency.

Using those figures the turbo needs to supply 27 lbs/min of air at 3500 rpm at a compression ratio of 1.76 and a max of 31 lbs/min at 4000 rpm.
This falls in the range of a 47 mm turbo. I believe this also fits the IHI RHF55 turbo that you mentioned.

Using a small .60-.64 A/R turbine housing you should be able to get max boost by 2000 rpm.
The engine will produce 420 ft.lbs of torque from 2000 to 3000 rpm.

Air temps out of the turbo will be around 200 degrees and around 135 out of the inter-cooler at 50% efficiency.

Wow..thanks for the extra info for sure.. Your comments on the head mods confirmed what I had hoped making it not as involved as some for sure.

Also the comment about the IHI I found interesting, I had researched them a couple of years ago while gathering parts for a Turbo-coupe motor I was building (an older change-course project)

If you haven't already you might want to read up on my other EGT probe thread. I gave some back story to my interest and history there. I genuinely appreciate the input..

I'll be following your progress on your 240 approach as well. Best wishes as you "play" at what drives you each day...
 
johns3524":3bi3aasn said:
If you haven't already you might want to read up on my other EGT probe thread. I gave some back story to my interest and history there. I genuinely appreciate the input..

I'll be following your progress on your 240 approach as well. Best wishes as you "play" at what drives you each day...

I'm following your EGT probe thread and looked at some of your photos. Great stuff!
I'm interested in your manual fuel control. Sometimes the old ways are a lot more fun. Hope you get it to work the way you want.
I see you would also like manual spark control.
Our shop can modify or fabricate if you need. Spokane WA.

Thanks for the best wishes on my 300 project. The engine is for a college student who wants a six that will be faster than his friends that have V8 powered trucks. He originally wanted to go turbo but that was more than his budget allowed.
We were looking at a 500+ hp build.
 
Cam and compression considerations:
This is long and detailed because of it's importance.

As you already know, the stock cam is 4 degrees retarded and would best serve a turbo application in an advanced position.
If you advance the cam from 4* retarded to straight up, the Dynamic compression ratio is increased 1/4 a point
so would need to drop the static compression ratio by at least 1/4 a point.

The stock cam has 2 more parameters that are not compatible with turbocharging.

The stock cam's .050" lobe lift duration is only 192* but the seat to seat duration is a very long 268*.
That is a 76* difference. (lobe minor intensity) If you split that in half you have 38* to gently open the valve the first .080" and the same to gently close the valve on the seat from .080" valve lift. (.050" x 1.6 rocker ratio = .080")
This was probably done for valve train and valve seat longevity.

The second parameter is the 110* Lobe Separation Angle.
Combine that with the 268* duration and you get 48* of valve overlap.

With the intake and exhaust valve open together for that long of a period during boost, part of the intake charge will go out the exhaust instead of filling the cylinder and you lose engine torque and turbo spooling time especially at low rpm.

The solution is to keep the 192* .050" intake duration but shorten the 268* duration 20 degrees to around 248*.

Just a note at this point.
Normally we don't get that concerned with the advertised duration timing events and focus more on the .050" duration points.
In your case we are looking for performance in a working range from idle to 3500 rpm where valve motion is relatively slow and low valve lifts have greater effect.

The exhaust side is a different story.
There are 2 parts to the exhaust cycle.
The first part is the blow down period where the exhaust valve opens and the high pressure exhaust exits and continues until the cylinder pressure equals the exhaust system pressure somewhere after BDC.
This is where the turbo makes use of the exhaust energy that would have been wasted.
The second part is where the piston travels to TDC during the exhaust stroke and any pressure left in the cylinder acts against the piston and becomes a "pumping loss".
The more back pressure the turbo system creates the more pumping loss and the more exhaust pressure is present when the intake valve first opens.
At low rpm the exhaust gas will enter the intake port and reverse the flow of the intake charge.
On our turbo race engine at WOT, low rpm, when trying to get boost before launch, the exhaust gas would come up the intake runners far enough to melt the plastic ends on the injectors.

The goal is to minimize valve overlap.
At a low rpm application like yours there is plenty of time to evacuate the exhaust from the cylinder and since there is a benefit to closing the exhaust valve early, the exhaust valve duration can be less than the intake valve duration.

After consulting with one of my cam suppliers, a good combination would be an intake .050" duration of 192* and an advertise duration around 248*
The exhaust .050" duration of 184* with a 240* advertised duration.
That gives a lobe minor intensity of 56* which is still reasonable for valve train longevity especially if you use the heads that have hardened valve seats.

We want to start the exhaust evacuation early to minimize residual exhaust gas in the cylinder and reduce the valve overlap period so the LSA should be increased from the 110* stock spec.

If we use a LSA of 114* the overlap with the new lobe specs will be reduced from the stock 48* down to 16*

New cam spec:
Intake 192*/248*
Exhaust 184*/240*
LSA 114*

The cam can be set straight up or with 1 or 2 degrees advance
Static compression ratio between 8.0 and 8.5 depending on the amount of intercooling and final cam position.
To be safe just go for something closer to 8.0 which will keep the Dynamic Compression Ratio in the high 6s

Valve lift can be just over .400"

Idle will be super smooth with grunt power from 600 rpm.

Crower cams shows a variety of lobes in this range.
 
:shock: :wow:

that is awesome!

this is pretty much the exact same project i'm working on as well, small turbo for torque and efficiency. let the 6 do what it does best and pull. leave racing to the kids... haha! i'm too old for that, i just want to tow a car trailer across the rockies whenever it strikes my fancy.


Its reassuring to see that i got almost the same numbers from a turbo calc that you did. the 420 ft lbs sounds way too good to be true, but is spot on the number i came up with. I think that is assuming no wastegate loss, which my research leads me to believe is impractical.

I was initially looking at the TD-04E-16T from a 'hot' volvo v70 2.5 L as found in the V70R's. Cheap and plentiful, also very reliable and internally wastegated

After some more research, i'm concerned with having too small of a turbo, I'd like to start making power as low as 1500 so i can hold high gear on the highway, but if I have to climb a mountain, down shift into 4th and rev her up to 3000, will she cook the exhaust valves and turbo bearings?

Will it hurt the turbo to be blowing off most of the exhaust gas through an internal wastegate from 2500 up? And if I do increase the wastegate pressure will the intake temps get too high?


i'm quite a few months out on this project, still getting the basics sorted out (brakes, transmission, axle, etc) and daily driving the truck, so it will move slow, but I'd like to nail down a turbocharger so i can start lurking craigslist and junkyards waiting for something to come up cheap.


my latest thought is to grab the small cummins/holset HY35 that most of the late 90's 6bt 12v engines had. folks have said its too small, but i'm also working with a 240 instead of a 300 for now. my thought is to scrap together something quick and dirty to daily drive and start breaking it, then build up a dedicated platform once i've learned what brakes and what i got wrong on the first one.
 
pmuller9":40csg6ey said:
Cam and compression considerations:
This is long and detailed because of it's importance.

New cam spec:
Intake 192*/248*
Exhaust 184*/240*
LSA 114*

The cam can be set straight up or with 1 or 2 degrees advance
Static compression ratio between 8.0 and 8.5 depending on the amount of intercooling and final cam position.
To be safe just go for something closer to 8.0 which will keep the Dynamic Compression Ratio in the high 6s
Valve lift can be just over .400"

Crower cams shows a variety of lobes in this range.

Well researched for sure..and dully noted. I can tell we will have a few things to discuss in coming days for sure.

I am responding to your other post about valve spring pressure now.. again dully noted.

I'm not against a new cam especially If there is a significant gain of performance in the lower rpms. I really perked up to the "Idle will be super smooth with grunt power from 600 rpm".. This interests me.

In planning this out, I understand I will need to watch CR making sure is is in the lowers 8's..how much will this effect any use NA?, Only time and use will tell possibly.

I suppose by now, you figured out my want of manual adjustment on-the-fly of MIXTURE, BOOST, and now my new love..TIMING.

With a vernier control cable I can micro adjust very precisely, so working out the details on the advance plate is soemthing I WILL be looking for sure..

Country Fried 6 mentioned it, and I was thinking about it already..so What comes to mind is...I'm sure your basic centrifugal timing can be set in a range...then you can tweak by vernier..probably setting it where the working range will allow for retard adjust and advance both..yet being able to push it all in to zero it out for starting or?..the neat part is..it's all a cable adjustment, like your manual choke..simple...Some of this may be necessary if/when you get a bad batch of fuel.

For me again the safeguarding of all of this is being abler to monitor the heat EGT,,and the fuel mixture (carb leaning device) In my mind, and AFR meter may just make you paranoid, thinking ur too far outta the box for the purists, but with this combination ur way past that IMHO...again the oil temps, pressures, and EGT reading along with your ears will tell you how close u may be to catastrophic issues.

I understand the problems of fuel pressure being indexed so, there really isn't much left to do except to choose a cam, pistons, and rings. I like SS valves at least, with a good valve job, and some prep on the ports, chambers..not much. ARP studs, a good 1024 gasket, basically then just need to enjoy the effect of the push pedal...
 
motzingg":an239ijl said:
:shock: :wow: that is awesome!
this is pretty much the exact same project i'm working on as well, small turbo for torque and efficiency. let the 6 do what it does best and pull. leave racing to the kids... haha! i'm too old for that, i just want to tow a car trailer across the rockies whenever it strikes my fancy.

Pretty kewl, and I've made note of your turbo comments..that may change for us in a few months when the project gets more mature..at least for me.
One this i miss about my earlier years of "flying". I read about it again the other day. It was the concept of "FLYING THE MOTOR" This really means using the various knobs provided to get the most out of the motor at any altitude or use or situation. The airplane pretty much flies it self..the motor needs to be tweaked to get, speed, economy, longevity etc. all with levers and knobs in the cockpit...That pretty much what I want to do I guess.

I get that a racer wants maximum when racing with short bursts of power while shifting, watching for other cars, and cops etc. I got time..just want it to run sweet at any altitude get a good balance of power and economy and last for a while...and the constant tweaking helps keep me awake and interested.
 
johns3524":1f8wuj7q said:
In planning this out, I understand I will need to watch CR making sure is is in the lowers 8's..how much will this effect any use NA?, Only time and use will tell possibly.

Either advancing the stock cam or using the suggested new cam bumps the Dynamic CR up.
You would need to drop the static CR down to 8.5:1 to compensate just for NA use.

On paper, going from 8.5 to 8.0 CR is a 2% drop in engine thermal efficiency.
That's supposed to translate to a 2% decrease in torque over the entire power band.
That seems low to me.

The one thing that is sure, you get a lot more margin with gas octane at 8:1 CR and you don't get stuck using premium gas.
It also gives you a lot more room to play with manual adjustable timing on the fly.

As you can tell I'm really interested in this project.

Is this engine going into the Bronco?
 
pmuller9":1p56kngp said:
johns3524":1p56kngp said:
In planning this out, I understand I will need to watch CR making sure is is in the lowers 8's..how much will this effect any use NA?, Only time and use will tell possibly.

Either advancing the stock cam or using the suggested new cam bumps the Dynamic CR up.
You would need to drop the static CR down to 8.5:1 to compensate just for NA use.

On paper, going from 8.5 to 8.0 CR is a 2% drop in engine thermal efficiency.
That's supposed to translate to a 2% decrease in torque over the entire power band.
That seems low to me.

The one thing that is sure, you get a lot more margin with gas octane at 8:1 CR and you don't get stuck using premium gas.
It also gives you a lot more room to play with manual adjustable timing on the fly.

As you can tell I'm really interested in this project.

Good morning. Well, I can appreciate the "interest" for sure. On my end putting these plans on paper has helped in the thinking process for me for sure, almost to the point of "over-thinking" as it always is for me. But as you wring out the plan eventually it will look clearer and solid as it translates into hard parts, and the intersections of no return are past, (mainly pistons and cam choices).

Another question has kept me awake some..that only mat be answered by reading, asking others, or testing:
"At what lowest RPM will this engine safely produce the most torque?' (all this while staying cool enuf for a practical DD)

Having a hunch about that rpm range..how can I best build some margins of strength, and reliability by other choices? Naturally all of the on-board tuning tools (leaning/enriching, boost and timing control) should handle whatever "influence" adjustments are necessary moment by moment) My gut tells me that it may not take much boost at that RPM but we'll see..

Of course timing is a critical factor..In my thinking I have thought of basically been thinking about (3) 12's as a starting point. 12 base, 12 centrifugal, and 12 manual advance..(and probably being all-in centrifugally at that lowest practical RPM point).. that could change of course.

I like the idea of non-ethanol premium as a base, but I know e85 is also part of the discussion. With the proper prep to the fuel system, (and it probably is a good idea) , using a Holley, it will be easy to build the carb if need be. I hate to paint myself totally into THAT corner though.

More thinking...AND reading.

But for now, pistons and cam choice. May I ask, it that an expensive "neighborhood" where those pistons you like are made?
 
motzingg":2mz1ujdj said:
:shock: :wow:
that is awesome! my latest thought is to grab the small cummins/holset HY35 that most of the late 90's 6bt 12v engines had. folks have said its too small,

hmmm..I'm not so sure about one of those myself..From what I've read, I would think it would be too big actually. It's capable of 20+lbs...which is kewl if you want to break things while testing I guess..be careful
 
johns3524":3ityb45z said:
motzingg":3ityb45z said:
:shock: :wow:
that is awesome! my latest thought is to grab the small cummins/holset HY35 that most of the late 90's 6bt 12v engines had. folks have said its too small,

hmmm..I'm not so sure about one of those myself..From what I've read, I would think it would be too big actually. It's capable of 20+lbs...which is kewl if you want to break things while testing I guess..be careful

As johns3524 said, it is too big for this application.
Most of the turbos used for diesel engines are designed for high pressure ratios and are not a good match for boost levels below 15 psi.
If you look at a compressor map you will notice the map gets very narrow below a pressure ratio of 2 or 15 psi.

The HY35 map shows a starting flow point of 10 lbs/min. This project needs a turbo that can flow 5 lbs/min without going into surge.

I couldn't find any specs on the TD04E-16T for the 2.5l Volvo V70 turbo.
Since it is used on a 2.5L engine I'm assuming it is too small for a 4.9l Ford six even at low rpm.
I was curious if it was small enough to possibly use it as a twin setup.
 
johns3524":d0e2uo9d said:
Another question has kept me awake some..that only mat be answered by reading, asking others, or testing:
"At what lowest RPM will this engine safely produce the most torque?' (all this while staying cool enuf for a practical DD)

Is this engine for the Bronco?

The only time the engine would be worked hard enough for cooling issues for water temp or turbo turbine temp is if you are towing a heavy load up a long grade.
Otherwise there shouldn't be a problem even for short high boost sprints as in the passing lane or just for fun.

Of course timing is a critical factor..In my thinking I have thought of basically been thinking about (3) 12's as a starting point. 12 base, 12 centrifugal, and 12 manual advance..(and probably being all-in centrifugally at that lowest practical RPM point).. that could change of course.

I see you having to monitor several gauges as you drive.
One of them should be a vacuum/pressure gauge so can keep track of the intake manifold vacuum or pressure to help you adjust the timing.
During the times while cruising on a long level strip and showing high manifold vacuum you may want to be able to get the total timing out to 40 degrees to maximize the fuel mileage.

The engine will let you know about the centrifugal advance but it will probably be all in by 2000 rpm.

I like the idea of non-ethanol premium as a base, but I know e85 is also part of the discussion. With the proper prep to the fuel system, (and it probably is a good idea) , using a Holley, it will be easy to build the carb if need be. I hate to paint myself totally into THAT corner though.

I agree that running on E85 only and having to find E85 stations as you travel would not be a good plan.
There is always the water/methanol spray for those times where you might need to control detonation.

But for now, pistons and cam choice. May I ask, it that an expensive "neighborhood" where those pistons you like are made

I put the order in for my pistons this past Monday and I'm waiting for their engineering department to finish so the can give me a price.
I will let you know as soon as I get that info.
 
pmuller9":2b3j4ndm said:
johns3524":2b3j4ndm said:
Another question has kept me awake some..that only mat be answered by reading, asking others, or testing:
"At what lowest RPM will this engine safely produce the most torque?' (all this while staying cool enuf for a practical DD)

Is this engine for the Bronco? actually this is up for grabs at this point

The only time the engine would be worked hard enough for cooling issues for water temp or turbo turbine temp is if you are towing a heavy load up a long grade.
Otherwise there shouldn't be a problem even for short high boost sprints as in the passing lane or just for fun.

Of course timing is a critical factor..In my thinking I have thought of basically been thinking about (3) 12's as a starting point. 12 base, 12 centrifugal, and 12 manual advance..(and probably being all-in centrifugally at that lowest practical RPM point).. that could change of course.

I see you having to monitor several gauges as you drive.
One of them should be a vacuum/pressure gauge so can keep track of the intake manifold vacuum or pressure to help you adjust the timing.
During the times while cruising on a long level strip and showing high manifold vacuum you may want to be able to get the total timing out to 40 degrees to maximize the fuel mileage. We're on the same page

The engine will let you know about the centrifugal advance but it will probably be all in by 2000 rpm.

I like the idea of non-ethanol premium as a base, but I know e85 is also part of the discussion. With the proper prep to the fuel system, (and it probably is a good idea) , using a Holley, it will be easy to build the carb if need be. I hate to paint myself totally into THAT corner though.

I agree that running on E85 only and having to find E85 stations as you travel would not be a good plan.
There is always the water/methanol spray for those times where you might need to control detonation.

But for now, pistons and cam choice. May I ask, it that an expensive "neighborhood" where those pistons you like are made

I put the order in for my pistons this past Monday and I'm waiting for their engineering department to finish so the can give me a price.
I will let you know as soon as I get that info.
good info.....have a safe weekend..
 
I was thinking about the possibility of using mechanical fuel injection where you can manually control the main and secondary bypass and have full control of the fuel. No carb and the problem of boost referenced fuel pressure goes away.
Just a thought.
 
pmuller9":wfv27ee5 said:
I was thinking about the possibility of using mechanical fuel injection where you can manually control the main and secondary bypass and have full control of the fuel. No carb and the problem of boost referenced fuel pressure goes away.
Just a thought.

Something to think about..and read up on of course..I'm sure they've made some advances since inception years ago..and since we're reading how about this?

https://en.wikipedia.org/wiki/Pressure_carburetor

AND: https://en.wikipedia.org/wiki/Bendix-Stromberg_pressure_carburetor

ps5 style actually ebay has a cple that were used on O470CI continentals in the 50-60s 230HP...well, more thinking I know.

I have decided to buy the leaning device from the maker as soon as he can ship, and try it on one of my Holley's' on the DD I have now. that may tell me if that type of thing is workable..
 
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