300 straight 6 to be turbo'ed

[LateApex]

I'm going to drop a 300 i6 into a '64 Econoline van and have a couple of questions for the forum, please.

First, I invested in a decent head that has been ported and had bigger valves fitted, so that's a starting point.

Second, I found two Weber carbs that came off a blow-through vehicle (a Maserati Biturbo).

Third, lurking in some other boards, I read that a good, cheap turbo for a 300 is the Chevy Duramax 6.6 Diesel unit. Any thoughts on this as a turbo for a Ford 300?

I've built a turbo Volvo i4, so I know a little about turbos in general, but what tips might you offer on what I'm trying to do here? For that build, I ran about 9.5 static compression at 0 deck for good quench and off-turbo response but I'm thinking the big six likes less compression so 0 deck but dished-centered pistons to keep quench without high static CR?

I think I'll try my hand at fabricating the intake manifold/plenum which means it will probably be stainless since I can't weld aluminum.

As for the exhaust manifold/turbo compressor mount, I'll try to carve up an existing exhaust manifold...but what style do you think would be best?

Since I'll have the 300 rebuilt, any tips to make it ready for turbo while it's apart and being built?

Thanks in advance for the advice and I'll keep you posted on my progress.

 

[inline300]

Whether the turbo is good for you is tough to say.

You wanna build the motor around the turbo or buy a turbo to match the engine?

 

[Does10s]

Forged pistons. O-ring the block and use a copper head gasket. Unless Cometic makes a gasket for the 300, but I HIGHLY doubt it!
Comp. ratio around 8.5 - 9:1 will work fine.
Camshaft with a 114 LSA. (very little if any overlap).
I don't know anything about that turbo. But a smaller turbo will be more friendly on the street.

Have fun with it!
Will

 

[Emerald 74 4X4]

I have had good results with my T04B Garrett. My cam isn't the most turbo friendly, so the engine doesn't run as efficient as it could until around 1800 and up. I don't know much about the 6.6 turbo. It may be a little "special". They tend not to use as common of adaptation for mounting of inlets and outlets of charge air, exhaust, coolant, and oil.. Turbos like that are usually a very snug fit in the V8 diesels for clearance and heat scavenging purposes.

 

[LateApex]

Thanks for the replies.

I was figuring forged pistons as a given and SEARCH turned up the o-ring and copper head gasket mods. So, 8.5 or 9 to 1 is a good compression ratio, seems to be the consensus. I wasn't sure the exact number on the lobe separation angle for the camshaft. I knew it was supposed to have little overlap. Can you run them advanced for more down-low power? Is the timing set even adjustable or do you have to have the advance/retard set in the cam?

I'll watch out for clocking and weird inlet and outlet positions on the turbos I research. Thanks for that tip. The Chevy could end up being weird.

We'll see how those Maserati carbs turn out, too, won't we?

 

[Emerald 74 4X4]

If this is going to be a street vehicle, I would weigh the copper gasket option a little. They can tend to leak coolant due to the lack of sealing surfaces. The compression holds great, but it's harder to keep the liquids contained. I am sure Does 10's has a couple secrets, but if I remember right, he does have coolant seepage issues on the Falcon.

 

[Emerald 74 4X4]

Oh also - ARP head studs a must. Rod bolts recommended. The mains are quite stout.

And Cloyes makes an adjustable cam timing gearset to adjust 4 degrees off zero, advanced or retarded, as well as zero.

 

[Does10s]

If this is going to be a street vehicle, I would weigh the copper gasket option a little. They can tend to leak coolant due to the lack of sealing surfaces. The compression holds great, but it's harder to keep the liquids contained. I am sure Does 10's has a couple secrets, but if I remember right, he does have coolant seepage issues on the Falcon.

Very true statement.
Copper head gaskets do tend to leak. We were no different. However....after some trial and error, I've found that putting "Right Stuff" silicon sealant on both sides of the gasket seals up the liquids very well.
Later,
Will

 

[Emerald 74 4X4]

So far with my Hi Performance Fel-pro head gasket I have not had any problems. I also have not run anything over 5 psi for any extended period of time yet.

 

[LateApex]

I know everyone hates this question because there are lots of correct answers, but ...

... what size turbo is good to use on a 300?

Ceteris paribus (all else being equal), a Ford 302 smallblock should use the same turbo, so I could lurk on the Mustang fora (Latin plural of forum) and copy them, right?

But I think the 302 has better volumetric efficiency and can be revved higher, meaning the airflow on that engine is greater than on the 300. But, how much higher?

I have a high-flow head with big valves and plan to go with the BBC roller rockers and I'll be using two two-barrel Weber 30mm carbs, so I've got the intake covered. I can build the exhaust for high flow, too. I could have the engine balanced to spin higher RPM, but I'm thinking 5000 should be the upper limit. It'd be nice to keep the nice low-end built into this engine, so that would mean a relatively quick-spool (i.e. small) turbo.

Any thoughts? Thanks.

 

[Emerald 74 4X4]

You should size the turbo to your horsepower output. If you have a big turbo, then you need an engine that will support that, or else it won't be very effective. If you have a have a small turbo, you do not necessarily have to build the engine to match it, but then your horsepower may not be what you want. So choose a turbo that matches the build you have, but also, match the build to suit the turbo. From there, you have a baseline to start from and can change the turbo, if need be, to suit more of an application if desired.

Now obviously there is a range of turbo size you would pick that falls within the displacement and volumetric efficiency of the engine you are building. That would where you would be correct about looking at something similar to a 302, for displacement purposes, while also looking at what this 302's application is, because they range from small to VERY large, because a 302's volumetric efficiency can be raised a little easier than the 300's.

Check out this site:
http://www.gnttype.org/techarea/turbo/turbopage.html

It's from a Buick Grand National site, but they have turbos down well and it has lots of great calculations that help you understand how a turbo should be sized and how it works in conjunction with the engine as far as pressure, volumetric efficiency, and temperature, among lots of other info.

 

[LateApex]

Thanks, Emerald. The Buick Regal site was informative. From that site plus the other parts you wrote plus Corky Bell's books, I think I'll build a 400 hp engine.

Two formulae I've found say 400 hp is either 400 cfm or 600 cfm. The latter number seems more prevalent, i.e. 1.5 cfm per hp.

My two carbs should support 600 cfm. The engine at about 80% volumetric efficiency should flow 350 cfm at 5000 rpm (naturally aspirated). At 85% VE, that could go up to 370 cfm.

Then, with 10 psi boost and 85% VE, I'd be at 634 cfm (or about 48 lb/min). So, I should keep the boost down to around 8 or 9 psi.

Looking at the turbo compressor maps, it seems that lots of turbos would work. I found a few, looked up their prices and availability and figured that a T04E 60 trim can be had for less than $200 new on e-bay and looks like it will perform admirably. It doesn't have water cooling or ceramic ball bearings, but it's one of the most common turbos out there and the numbers seem to work.

At maximum boost, I'm a little to the right of the compressor map at 9 psi, so that's less than perfect. At 2500 rpm, I'm in the middle of the efficiency island, so that's very good. At 1000 to 1500 rpm, I'm still on the map, so I won't have any surge. I guess, if anything, this particular compressor might be hard-pressed to give efficient boost on a 300 CID engine at 5000 rpm but at low engine speeds, it should respond very well.

Looking at the map for the T-61, the turbo can handle the higher-end demands much better and still puts me on the map at low engine speeds (stays out of the surge area). The drawbacks to the T-61 over the T04E 60 trim are that 1) there is no integrated waste gate, so I'd need to add one for more $, 2) these turbos are not nearly as common and may cost more and 3) this turbo really wants more boost, like 10 psi. Maybe that last one isn't so bad, after all but I'd need to add carburetion.

So, I basically have it narrowed down to two turbos. Any thoughts on my reasoning?

 

[LateApex]

Correction: for some reason, I thought the T-61 had no internal waste gate. Now, I find one on e-bay that does have one.

 

[Emerald 74 4X4]

I contemplated the T04E when I was turbo shopping too. The T04B is similar, but the compressor maps are different and yield slightly different results when crossing axis.

I think many turbos can be built with an internal waste gate, even in the T4 flanges. A lot depend on the turbine housing mainly. The smaller turbine housings can tend to have one because of their ability to speed up very fast. That is why almost all the T3 flanged turbos have an internal waste gate.

 

[LateApex]

The T04B-H3 looks really nice because it won't surge at low RPM. Its upper limit of abut 400 flywheel HP is right about where I want to be, too. So, it might be a really fun turbo for a street engine. If I ever got crazy with wanting to make power, I'd have to go larger. This seems like a perfect "starter" turbo.

If you wouldn't mind answering another question: when I look on e-bay for the T04B, there are several. What trim or other identifying feature is the H3?

Thanks

 

[Emerald 74 4X4]

A lot of it has to do with actually measuring the major and minor of the wheel diameter to determine what it is, if it is not stated. If the seller states what it is, I would research their history to make sure they sell what they state to be true, or question him. Find the major and minor wheel measurements for the H3 and ask them with the measurements.

I remember looking at the H3 as a consideration, but I think it was too big for my 250-300 HP goal, which I probably have not quite accomplished!

If you can locate a shop that does turbos, like a fuel injection shop, a performance shop, or something, you may be able to purchase a wheel and then have it mounted and balanced to an existing turbocharger.

http://www.blaastperformance.com/index.php
This is where I purchased mine for about 350 or 400 bucks. Personally, I was not impressed by the quality of the part, but it was sound to say the least, and obviously working. Since I live in Alaska and they are in Canada, shipping prices and customs were something keeping me from sending it back. It was the proper A/R ratios that I stated I wanted at least. I think a little shopping can yield a little better results though.

 

[LateApex]

Doing more research ...

... it seems like a lot of what I'd thought earlier about having a nice, quick-spool turbo won't work at all on the top end.

They say that engineering=compromise and here's an example of that truth.

Simply, a turbo on my particular setup that will support 600 cfm / 48 lb per minute / 400 horsepower needs to be big enough to create those flow numbers. The little guys look good up to about 300 horsepower but will choke out past that.

At this point, I'm thinking a GT35R. It'll support about 450 horsepower but it's going to be a little more laggy than I'd like. Again, compromise. At least it'll be ball bearing, which will help it spool a little quicker.

 

[Emerald 74 4X4]

Yep, and that is why all the new diesels use the variable vane or variable nozzle turbos to keep the back pressure before the turbo up and exhaust velocity moving past the turbine wheel. It's a careful priority list to go through to make th turbo work for your application.

 

[LateApex]

Thanks for your comments, Emerald; much appreciated.

So, are you using a t04b on yours? Are you liking it? I understand we're building different engines, but I'm curious what your experiences have been.

 

[Emerald 74 4X4]

I am using a T04B with .60 compressor and .82 turbine housings. So far I am liking it. It really comes alive when the cam kicks in. If I had a more turbo friendly cam with similar lift characteristics, I think it would have more low end power and spool a bit faster. Also run cleaner and not so rich in the lower RPM's. Right now, I think the T04B is a good turbo with enough left in it make more than adequate power, for me anyways. I would say my engine, on 5 psi boost, empty, feels like a modern diesel in a pickup truck (6.0L, Duramax, maybe a Cummins), as far acceleration speed/feel goes. But, I have not "worked" it with a load to find out how that torque and power hold up. It has all been empty weight. I have taken it out on some steeper inclines. It slows like any other truck if you cruise without giving it the fuel, but push a little on the pedal, the boost jumps up, and it feels like the hill isn't there anymore.

I have a stainless turbo header (6 into 1) that I made, but it needs to be modified to fit with the EFI lower intake. I messed up on the dimensions or something. It has just been sitting around until I get some time. Right now I am running both banks of cylinders (123, 456) into EFI manifolds, a Y-pipe, and then it collects without division at that point, so I am not benefitting from the division of the turbine housing and bank separation.

It's hard to keep the boost from jumping up there above the 5 psi mark. That is on 87 octane. If I run 91 octane, I can push almost 10 psi boost under most conditions, but safely boost to 7 or 8 under all conditions. Since I have not rigged up a boost controller, I just watch the boost pressure and take it easy until I get some more time and money to implement a boost controller. I want to use the electronic one that Megasquirt has implemented. It would make it a nice clean setup. I am also seriously thinking about upgrading my MSII to an MS3.