Guess the horsepower game, Ford 311 SBF

[Stangman]

i like the coated bearings. Is it a harder surface like a shell or can you csratch it with your nail.

[JC-427Stroker]

It had 10.59:1 compression and we ran 112 Sunoco.  I think we would have benefitted from a pump gas mix and I will try that when we go back.  The exhaust ports were a little on the sooty side.  It has a lot of cylinder pressure due to the cam being so advanced, so I really didn't know what I could get away with.  We played it safe the first time and I can back into something else on the next session.

I ran 5W-20 oil.  Some of the rod bearing clearances were .0018-.0019".  It completely makes sense to me to set them up a little tight, since aluminum expands so much.  We just gave the engine ample time to warm up. 

I pulled the pan off the other day to change the rear main seal and the timing cover seal to a double lip/teflon setup for a vacuum pump addition.  I checked the bearings while I was in there.  You can still see my mic tracks.



Aluminum rods do make people nervous.  This engine is gonna go in a street car after I thrash it on the dyno for awhile.  It will keep the aluminum rods. 

I attribute the horsepower to a really nice set of heads, a well-chosen camshaft, and some careful measuring and planning.  Tight quench with a little engine that pulls hard on the ports.

Thanks for the info.  Were you able to spin it over for a cyl psi test ?

That's a great little test bed ... Have fun with it.

[blykins]

It had 10.59:1 compression and we ran 112 Sunoco.  I think we would have benefitted from a pump gas mix and I will try that when we go back.  The exhaust ports were a little on the sooty side.  It has a lot of cylinder pressure due to the cam being so advanced, so I really didn't know what I could get away with.  We played it safe the first time and I can back into something else on the next session.

I ran 5W-20 oil.  Some of the rod bearing clearances were .0018-.0019".  It completely makes sense to me to set them up a little tight, since aluminum expands so much.  We just gave the engine ample time to warm up. 

I pulled the pan off the other day to change the rear main seal and the timing cover seal to a double lip/teflon setup for a vacuum pump addition.  I checked the bearings while I was in there.  You can still see my mic tracks.



Aluminum rods do make people nervous.  This engine is gonna go in a street car after I thrash it on the dyno for awhile.  It will keep the aluminum rods. 

I attribute the horsepower to a really nice set of heads, a well-chosen camshaft, and some careful measuring and planning.  Tight quench with a little engine that pulls hard on the ports.

Thanks for the info.  Were you able to spin it over for a cyl psi test ?

That's a great little test bed ... Have fun with it.

Got caught up in making horsepower last time, but can do that the next time around.   DCR with Pat Kelley's calculator shows 8.9................

[JC-427Stroker]

Your power numbers are all the more impressive at 10.6:1 compression. 

Great combination.

[blykins]

Ok, so I'm gonna have to make a choice:  try vacuum pump first or try this beauty that I just got from Mr. Craine.  And yes, it's Australian, not Chinese LOL

[JC-427Stroker]

Was it set up with light tension oil rings ?

I like that manifold... Sexy.

[frnkeore]

I'm interested in what that Parker Funnel Web manifold will do, too. But, if a larger carb, reduced power, on a ported Vic Jr, that would indicate that the intake flow, was maxed out at 750 cfm or, that there was something wrong with either the Edel manifold design or the larger carb you tried, if it picks up power with the PFW.

There are two more manifolds worth trying, the Super Victor and the Holley 300-275 Tunnel Ram.

[blykins]

I'm interested in what that Parker Funnel Web manifold will do, too. But, if a larger carb, reduced power, on a ported Vic Jr, that would indicate that the intake flow, was maxed out at 750 cfm or, that there was something wrong with either the Edel manifold design or the larger carb you tried, if it picks up power with the PFW.

There are two more manifolds worth trying, the Super Victor and the Holley 300-275 Tunnel Ram.

The larger carb was an older Holley 830.  They just can't hang with the newer carbs with their fancy billet metering blocks, venturi designs, and fancy emulsions.  That's why I put "small carbs" in quotes on the other page.  Even though it was "just" a 750, they actually flow ~800 cfm, +/-, and make more horsepower than the older "bigger" carbs. 

[frnkeore]

So, a real 850 jeted right or 1000HP would be worth trying.

What carb are you going to run on the FW?

[blykins]

Intake from Joe came yesterday.   Nice lookin' piece.  385cfm, which I assume is an average flow as Joe usually balances the runners. 

Even though the intake flows more, it could totally be a wash as the engine may not want that runner length.   You never really know for sure until you try and I haven't had much luck with software determining the optimal runner lengths.   Even if I lose a few ponies, I think I'll keep it as the intake just demands attention. 

Got it all swapped this morning.  Took all of 15 minutes and I remembered how much quicker it is to change an intake on a small block vs an FE....LOL

I went ahead and swapped it because I shot myself in the foot when I was at the dyno last time.  I was using a borrowed carburetor and I don't have access to that carburetor anymore.  Instead of going down, getting a baseline with a new carb, and then pulling the VJ to find out that the intake needs cut would have been a slight kick in the pants.  I'm pretty confident that the new carb has the same metering blocks, baseplate, etc., so it should be pretty close.....crossing my fingers.....

Any guesses as to what it will do?

BTW, the pictures show the engine with a 2" Super Sucker.  I'm almost 100% sure it won't want the 2" carb spacer, but I had to slap it together just to see how mean it looks.

[Joe-JDC]

Yes, that is average flow at 385 cfm.  All ports were between 383-387 cfm.  You need a camshaft change to .650" lift or more to see an appreciable difference, IMO.  It would have been neat to see how this engine ran with your first camshaft at .710" lift.  I have cut the top of the guides down a small amount to get valve stem seal clearance and still have the seals grip the guide.  You might try that next time.  Joe-JDC

[blykins]

Yes, that is average flow at 385 cfm.  All ports were between 383-387 cfm.  You need a camshaft change to .650" lift or more to see an appreciable difference, IMO.  It would have been neat to see how this engine ran with your first camshaft at .710" lift.  I have cut the top of the guides down a small amount to get valve stem seal clearance and still have the seals grip the guide.  You might try that next time.  Joe-JDC

I would have done that, but the seals touch the locators.  I also wouldn't have had any piston/valve clearance.  I'm at .078" on the exhaust side right now. 

If I want to run another cam, it will require longer valves and different pistons. 

Even if I pick up 6-7 hp, I'll be pleased because I think I can pick up another little wad with a vacuum pump. 

Joe, you've been my dyno mule intake supplier LOL....JJ got the adapter and tunnel ram and this little guy got the FW.