Ford SB Stroker for Roaring Forties GT40

[Ron Earp]

Colin I checked that link out, but those things are pricey to modify already pricey IDAs. This might not be an easy project because I don't think the 48s are going to be large enough based on flow calculations. It might have to be a 4bbl to handle it, but I really don't want that as it doesn't look too good although it would have great performance I think. Decisions decisions...

 

Hi Ron,

What centerline and lobe seperation is that cam running?

 

[colin artus]

So you lose some topend hp, you'll have enough to spare from the sound of it. A slight restriction in the upper rev range won't stop the engine from revving to your chosen rpm. Perhaps you can find someone with a set of original 50 idas who doesnt know what they are?

Colin Artus

 

[Ron Earp]

Colin,

you are right on the upper end, but it'd be nice to have it pull strongly all the way through. Dave I'll get the cam card and get specs on the lobe seperation for you.

Ron

 

[Charlie M]

Ron/Bill,

What is the thermal coating you discussed for the piston tops and combustion chambers? I'm reading a book on engine management systems and the author mentioned it as a good idea but offered no details.

BTW Ron, that sounds like a killer engine for one of these cars. I'm planning a milder version of the 347, around 400 fwhp. I'm anxious to see how the Audi box holds up for you at 530hp.

Thanks,
Charlie

 

[Ron Earp]

Charlie,

It probably won't hold up well at all, but I'm out to collect data and let everyone have it at face value. So, early next year I'll review my RF GT40 objectively and then I'll review use and driving of the car. My Audi box is brand new, all new parts, so it is as good as it is going to get for the average GT40 guy interested in an Audi/Getrag box. Still don't think it will take a lot of track days, but I hope I am wrong on that account.

As for the coating, that stuff is proprietary and they don't tell you much about it, but I think it is a ceramic layer of some sort. About all you can do is find out that "it reduces heat, yada yada yada". My engine man wanted the stuff on there a lot more than I did, so there it is. I personally don't think much of it, but that is me.

http://www.swaintech.com/swdoes.html

They have some pricing info there too, not too expensive really if that is what you want.

 

[Charlie M]

Thanks for the info Ron. Swain isn't far from me so shipping shouldn't be too bad if I decide to go that way.

You'll have your car running long before me (deluxe kit due in January) so I'll be anxiously waiting to hear your experiences with the transaxle. I hope it works out well for you. What's "plan B" if the Audi box doesn't hold up?

Charlie

 

[Ron Earp]

You know, with the luck I've had racing, Plan B won't work either. In fact, I've proposed changing our race team name from "RTP Racing" to "Plan C Racing".

I think if it craps out then I'll bite the bullet and do a ZF, maybe a Porsche box. Either one seem like they can last in the application but I'm sure it'll require some cutting and fitting of the chassis. But, that is a nice thing about space frames - want to change something, no problem!

 

[Bill D]

Ron-

Do the thermal coatings hold up for a long time in a street engine? Or would the cost be a waste of money?

Thanks
Bill D

 

[Ron Earp]

I think they'll hold up longer on a street engine than a race engine, that is for sure. Lots of people use them in racing and say they are good, but I've never really seen any hard core data on effects. Seems to me a little like oil choices as some folks say "I only run XXXXXX Synethic in my car, no problems!". You know, how many engines do you know that failed because of TYPE of oil? I've seen some that fail because of loss of oil pressure, but that would have happened regardless of oil type. Me - I run good old dead dino stuff in my engines, no problems, just like the $9 qt Lubrication Technologies guys claim, no problems, except I only spend $2 qt.

Oil, women, beer, coatings, gun control, abortion - all the same, everyone has his/her opinion and stick to it regardless.

 

[Alex Hirsbrunner]

Speaking of a loss of oil pressure, I'm wondering if the silicone anti-drainback valve in the oil filters I'm using (purolator) reduced the amount of damage to my SBF last year after snapping the oil pump driveshaft on the way home from Road America (perhaps by letting some oil in the galleys trickle slowly to the lower parts of the engine).

After noticing zero oil pressure on the highway (who knows for how long), I pulled over, listened, checked temps etc. figured bad sender and drove home (80 miles @ 3500 RPM) - yes I am a moron!. Noticed a rear main leak when I got home, but other then that no noise, overheat nothing. replaced the sender, no joy. Tore it apart (found chunks of oil pump drive shaft in the pan) and only the pushrod tips were damaged/discolored, and some minor (<.001") scuffs in the cylinder bores which honed right out.

How is this possible? - I'm still shocked it didn't grenade on the way home!

I did end up replacing the rings, cam/lifters ,main bearings, oil pump etc. but only because I couldn't believe they were still good - they sure looked decent.

Regards,

Al

 

[Ron Earp]

Dave, I am picking the motor this Thursday and will get the cam specs on it for what you want. There are some bits in there that are more expensive than we'd planned on - Jesel rockers and some other bits, but I'll detail them all out on the build sheet later in the week. I think Steve might be right on a 4bbl for this thing, but we'll see what happens on the dyno.

Ron

Ron

 

Thanks Ron,

I look forward to the details.

Why not go for a Kinlser injection system. I know you like simple, but to me Injection is much simpler than Carbs. All you need to worry about is choke and injector sizing. The rest is simple set up.

To me it seems much easier to do a power run on the dyno, Hold the engine at a relative speed/load and adjust a field on a map. Then to look at plug colors, Fuel flow and then play around with Power valves, Primary and secondary jets, emulsion tubes and in the case of webers, ventury size and choke variables.

I was a carb guy through and through untill the last motor when I tried TB's and ECU. I doubt I would go back to carbs now.

Of course injection does nto look the part!

D