Dyno’d the 352 again today, with a BT MR 8V this time....

[tks08]

Keep up the good work.  Little JJ gives me some real motivation for my '58 EDC 352 covered in grime in the back corner of my garage.

[WConley]

You two are hilarious with your quoting.

I'm enjoying it too 

[Tommy-T]

Sorry, what I meant was a Tunnel Ram.

If I had a set of mech secondary carbs, I could be persuaded into trying one on one of Jay's adapters.  Having to keep buying 2x4 carbs gets expensive....

Why is it mandatory to run mechanical secondary carbs on a tunnel ram?

[winr1]

https://www.fordfe.com/history-super-stock-352-t7407.html

Bill Heinson and his 352




Ricky.

[blykins]

Sorry, what I meant was a Tunnel Ram.

If I had a set of mech secondary carbs, I could be persuaded into trying one on one of Jay's adapters.  Having to keep buying 2x4 carbs gets expensive....

Why is it mandatory to run mechanical secondary carbs on a tunnel ram?

Tommy, don’t recall saying it was mandatory, but if I were to do a Tunnel Ram, I’d do a pair of mechanical secondary carbs turned sideways. 

Tunnel ram would certainly be tempting.  And would look good.

[Joe-JDC]

Sounds like it is time to go to a 2.125" intake valve, very long rod, rod journals turned down to 2/2.100", mains -.030-060" if bearings are available, and pistons with ceramic coating on crown and coated skirts, .9/.9/2.0 rings, and back to a Street Dominator, or RPM fully ported.  Polish crankshaft, windage screen, oil pump pressure lowered to 50# at WOT, IH oil filter adapter with filter, 5W-20 AmsOil, 950 carb., and electric water pump.  It will take a major change to increase the horsepower from where it is now.  It's only money.  Joe-JDC

[plovett]

Okay, no more quotes.  I'm glad it was entertaining.

Brent, the reason I asked about intake manifolds in relation to cid and rpm was because you brought it up.   You implied that dyno data for the same intake at similar hp levels, but on a different displacement and rpm range was not relevant to what you are doing.  I thought you might want to expound upon your assertion.   You mentioned that the BT2x4 brought the peak rpm down a bit.  Longer runners?  I wouldn't think the 2x4 dual plane would have longer runners than a 1x4 PI intake.  I think they'd be a littler shorter on average?  You also mentioned plenum design and runner shape, but are not opening up about it.   So do you know more about it, or is it just based your dyno experience? Or?   

This is interesting.   For instance, does a smaller higher rpm engine want shorter runners to get the same peak hp as a bigger and lower rpm engine, that is otherwise similar?  I could see some going the opposite direction.   That is, using longer runners to try to crutch the already weaker low rpm power.  Sometimes intuition is wrong, though.   Are we talking big differences or more subtle ones? 

Project JunkyJunk is certainly not the average combo.  Combinations that are at the edges of the range tend to make it easier to see trends.  Is that happening here or is the BT 2x4 acting like it does on other similar hp combos?

Thanks,

paulie

[Joe-JDC]

Paulie, the BT 8V has passages that go from the very back to the front on each bank to all the ports on that plane, making for very long runners.  It is also very convoluted and narrow in places making it difficult to get a good increase in airflow.  Check out Jay's book again, and you will see on the stroker 427 that the ported BT 8V(mine) was only a little better than the stock BT 8V. On pages 182-183, my ported Streetmaster made within 10 hp of the BT and more torque.(page 254 -604.1/632.8hp) A TW would be the next logical step to finding if JJ would respond to more carburetion or intake height.  For all the testing, I still think a Streetmaster ported to 340 cfm, a Street Dominator ported to 340 cfm, or a Ported RPM will give JJ all the airflow it can use in it's current iteration.  JMO, Joe-JDC

[blykins]

Sounds like it is time to go to a 2.125" intake valve, very long rod, rod journals turned down to 2/2.100", mains -.030-060" if bearings are available, and pistons with ceramic coating on crown and coated skirts, .9/.9/2.0 rings, and back to a Street Dominator, or RPM fully ported.  Polish crankshaft, windage screen, oil pump pressure lowered to 50# at WOT, IH oil filter adapter with filter, 5W-20 AmsOil, 950 carb., and electric water pump.  It will take a major change to increase the horsepower from where it is now.  It's only money.  Joe-JDC

I'm not ready to throw in the towel yet.

Normally we look to the displacement, head flow, intake, compression, and cam to get us in the general horsepower area we want to be, and then we look to the "fine tune" things such as you described to give small incremental increases. 

I do have some rods coming in a few weeks.   I wasn't focused on the long rod/short rod argument, but mainly on the fact that I'm looking at more compression down the road and I don't want a domed, 1.920" compression height piston. 

We are right at 1.3 hp/ci with this combo.  A really strong FE on the dyno I use is about 1.5 hp/ci. 

I think there's a little more here in the "general components".  Obviously, going from 10:1 to 12.5:1 would probably net me a 40+ hp gain, but I'd like to dial in the rest of it before I go to that step. 

I have another camshaft coming.  We will see.

On the intake side, the TW, or an adapter with a larger single plane intake may have to be in the cards.   I know a Strip Dominator on a 351C will support 620 hp and 8000 rpm in unported form.  That might be a good one to try on JJ.

[plovett]

Paulie, the BT 8V has passages that go from the very back to the front on each bank to all the ports on that plane, making for very long runners.  It is also very convoluted and narrow in places making it difficult to get a good increase in airflow.  Check out Jay's book again, and you will see on the stroker 427 that the ported BT 8V(mine) was only a little better than the stock BT 8V. On pages 182-183, my ported Streetmaster made within 10 hp of the BT and more torque.(page 254 -604.1/632.8hp) A TW would be the next logical step to finding if JJ would respond to more carburetion or intake height.  For all the testing, I still think a Streetmaster ported to 340 cfm, a Street Dominator ported to 340 cfm, or a Ported RPM will give JJ all the airflow it can use in it's current iteration.  JMO, Joe-JDC

Joe,  thanks for the to the point response.   I actually have a 2x4 BT here and will look at it again right now.  I was thinking the two carburetor locations made for slightly shorter runners, but apparently not.   I do remember that port matching the BT 2x4 made little difference.   

It will be interesting to see if more airflow at the intake will JJ or if the restriction is in the heads.

Brent, in my line of work people like you are very dangerous.  Egos and the need to be right and/or look confident all the time lead to product being let through when it shouldn't be.  It is a loss of a quarter million dollars IF it is caught after production.   10x more so if another egotisitical person lets it through the next step again and it gets to the customer.  Look up the Dunning/Kruger effect.  I don't know if I spelled that right.  Might be another "e".    I am glad you are just building engines.

paulie

[blykins]

Paulie, the BT 8V has passages that go from the very back to the front on each bank to all the ports on that plane, making for very long runners.  It is also very convoluted and narrow in places making it difficult to get a good increase in airflow.  Check out Jay's book again, and you will see on the stroker 427 that the ported BT 8V(mine) was only a little better than the stock BT 8V. On pages 182-183, my ported Streetmaster made within 10 hp of the BT and more torque.(page 254 -604.1/632.8hp) A TW would be the next logical step to finding if JJ would respond to more carburetion or intake height.  For all the testing, I still think a Streetmaster ported to 340 cfm, a Street Dominator ported to 340 cfm, or a Ported RPM will give JJ all the airflow it can use in it's current iteration.  JMO, Joe-JDC

Joe,  thanks for the to the point response.   I actually have a 2x4 BT here and will look at it again right now.  I was thinking the two carburetor locations made for slightly shorter runners, but apparently not.   I do remember that port matching the BT 2x4 made little difference.   

It will be interesting to see if more airflow at the intake will JJ or if the restriction is in the heads.

Brent, in my line of work people like you are very dangerous.  Egos and the need to be right and/or look confident all the time lead to product being let through when it shouldn't be.  It is a loss of a quarter million dollars IF it is caught after production.   10x more so if another egotisitical person lets it through the next step again and it gets to the customer.  Look up the Dunning/Kruger effect.  I don't know if I spelled that right.  Might be another "e".    I am glad you are just building engines.

paulie

Thanks, I'm glad I'm building engines too.  I really enjoy it. 

[chilly460]

It’s logical to look to the I take due to wave tuning, even though the intake has supported more power on other combos.  On the same thought, what’s the minimum CSA on the heads?  Looking at the flow numbers you’d think there’s no way they’d be the bottleneck, but any way the rpm is causing the head to go turbulent? 

[blykins]

It’s logical to look to the I take due to wave tuning, even though the intake has supported more power on other combos.  On the same thought, what’s the minimum CSA on the heads?  Looking at the flow numbers you’d think there’s no way they’d be the bottleneck, but any way the rpm is causing the head to go turbulent?

I suppose anything is possible. 

The reason I'm leaning toward the intake is that the peak hp rpm changed so drastically.  A 400 rpm change is pretty big, that's about what I saw from going from a non-ported head to the ported head.   In addition, we did gain 7 lb-ft of torque and the peak torque rpm changed as well. 

I have yet to do any wave tuning calculations.   Will try to work on that this weekend. 

I expect the camshaft to make a difference, but I don't know how much.   It has a lot of overlap for this size engine and I think I made the wrong call there.

[frnkeore]

Just looking at these numbers, my first impression is that the 2x4, did what you might expect on the torque side, raising the peak 200 rpm but, on the HP side, it did the  opposite, like it was choked off. 600 rpm is a LOT to loose, if you increase the air flow.

Was the A/F numbers about the same at 5.6k as at 6.6k?

Peak Horsepower:  465 @ 7200
Peak Torque:  410 @ 5400

Peak Horsepower:  464 @ 6600
Peak Torque:  417 @ 5600

To verify the manifold causing this, I would run it with a pair of 660's, 715's or even 750's and see what happens.

Edit:
Did you have a vacuum gauge hooked up on the 2x4 run?

[blykins]

Just looking at these numbers, my first impression is that the 2x4, did what you might expect on the torque side, raising the peak 200 rpm but, on the HP side, it did the  opposite, like it was choked off. 600 rpm is a LOT to loose, if you increase the air flow.

Was the A/F numbers about the same at 5.6k as at 6.6k?

Peak Horsepower:  465 @ 7200
Peak Torque:  410 @ 5400

Peak Horsepower:  464 @ 6600
Peak Torque:  417 @ 5600

To verify the manifold causing this, I would run it with a pair of 660's, 715's or even 750's and see what happens.

Edit:
Did you have a vacuum gauge hooked up on the 2x4 run?

A/F ratios were pretty much the same, within .2 of a point. 

I was not running a vacuum gauge, but opening the secondaries only gained us 15 hp.  Before we made them open, it was making 450 hp running on essentially the "front" barrels of the carbs.