302 Down On Power

grips · Jun 13, 2014

Well completed my Second v8 Ranger a while ago. The 302 feel down on power and I am sure the 4.0l OHC pulled stronger in fifth gear. When I push is to about
100mph in 4th gear selecting 5th it will start losing momentum till it reach about
85mph. It will maintain 85 at full throttle.

The engine specs are .

302 block bored .040 over.
AFR 165cc Renegade heads.
Efelbrock Performer RPM intake
600 Holley with vacuum secondaries.
PRW - Roller rockers.
Mallory HIE dissy.
Edelbrock 2122 flat tappet cam.

Diff ratio left standard as on the 4.0l sohc 4.1
Gearbox Borg Warner T5 0.85 OD.

First suspected the Holley thinking the secondaries not opening testing it with a paperclip I found it to function as it should.
At this stage suspecting the cam.
Want to try a COMP roller cam part no 35-320-8 grind XE264HR-12 . As I have to convert to roller it is quite an expensive exercise here in South Africa.

Is this the best cam choice or is my current cam up to it and something else wrong? Help would be appreciated.

My build http://www.therangerstation.com/forums/showthread.php?t=145665

Rowdy Fitzgerald · Jun 13, 2014

What fuel pump are you running? Is it supplying enough fuel?
Is the timing correct?
Simple things and they tend to get over looked because they are so simple.

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kimcrwbr1 · Jun 13, 2014

You can check the timing chain for slop but what is the total advance for your dizzy. Dont focus too much on base timing you want the proper total advance. Especially with a built motor advance the timing to where it pings and then back off to the point it no longer pings. What color are the plugs they should be a toasty brown if they are white increase the high speed jets a size or two you dont want to cook the pistons and valves runnig lean. Fuel is the only thing cooling the valves. just a couple thoughts.

grips · Jun 13, 2014

Rowdy Fitzgerald said:
What fuel pump are you running? Is it supplying enough fuel?
Is the timing correct?
Simple things and they tend to get over looked because they are so simple.

Sent from my iPhone using Tapatalk

kimcrwbr1 said:
You can check the timing chain for slop but what is the total advance for your dizzy. Dont focus too much on base timing you want the proper total advance. Especially with a built motor advance the timing to where it pings and then back off to the point it no longer pings. What color are the plugs they should be a toasty brown if they are white increase the high speed jets a size or two you dont want to cook the pistons and valves runnig lean. Fuel is the only thing cooling the valves. just a couple thoughts.

Running a Holley Blue electric pump 152gph with regulator.
Timing is set at 32 deg total.

The engine is very smooth running , revving crispy, is just feel like it is short that extra oompf.

Rowdy Fitzgerald · Jun 13, 2014

Hmm I'm not good with timing. Is that what it's supposed to be for that cam or is that just average?

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dangerranger83 · Jun 14, 2014

Wind resistance may be to much in 5th gear for it. 4th gear is probably where it can stay in its power band area and be able to do 100mph.

And how do you test if the secondaries open with a paper clip...never heard of that?

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grips · Jun 14, 2014

dangerranger83 said:
Wind resistance may be to much in 5th gear for it. 4th gear is probably where it can stay in its power band area and be able to do 100mph.

And how do you test if the secondaries open with a paper clip...never heard of that?

Sent from my SPH-L710 using Tapatalk

I bend a paper clip and put it on the shaft of the vacuum mechanism so when the secondary open it is forced down the shaft staying at the maximum opening position of the secondaries.

Well this Ranger did run to its speed limiter of 113mph with the 4.0l holding speed in 5th gear.

grips · Jun 14, 2014

Thanks everyone think I found the problem. The cam that was supplied is a 7122
and not a 2122 as ordered. Some how I slipped picking this up.
The 7122 is rated to perform between 2500 and 6500 rpm and matched to a Edelbrock Torker II intake.

Please some advise on the COMP roller cam part no 35-320-8 grind XE264HR-12
Is this the right choice for street use. This Ranger will do the minimum 4x4 work.
I would like it to have enough torque for towing.

yankdownunder · Jun 18, 2014

The stock HO cam [202/202] is a good torque cam. May be a bit small for a 347, though. If the cam you have is best suited to a 360* single plane manifold, it is pretty big [bigger than a 202/202].
Do you have the vacuum advance plugged into the ported outlet in the carb?
The amount of advance can be adjusted [in Ford distributors and Mallory] via a allen wrench through the nipple on the distributor. Maybe not getting enough "total advance". This should be about 30*. Initial advance should be about 7*. I usually set initial advance with a vacum guage [disconnected and plugged vacum hose], adjust timing for highest vacum, then lightened springs in dist., with total advance adjusted via hex/allen screw in the hose nipple on the dist. Small Ford like LOTS of advance, cold thermostat/cold engine temp [160* summer], and rich mix.
You can adjust the vacum secondaries opening with lighter springs [lighter=faster] in the dashpot. I usually ended up with the lighter yellow on a 9.0+ cr small block with a vacum secondary 600 cfm Holley. Make sure you've got an anti-back fire check valve.
I much prefer the Weber designed 4bbl [Carter AFB and Edlebrock], they use weighted vanes for the secondaries. Easier to tune, better power, better fuel economy...
Even a semi stocker cam should pull more than 85.
Valve lash [preload for hydraulic lifters], may be valve float?
Get engine to idle at lowest RPM, warmed up, adjust timing for smoothest/lowest idle. Shut off engine, loosen the valve cover bolts. Start engine, remove valve cover, loosen rocker nut til you hear a "CLACK-CLACK", then tighten 1/2 turn. This is for adjustable rockers.
That's all I can think of. Probably in the "total advance" or not ported vacum as you'd be near zero vacum at WOT in 5th. If the vacum hose is not to the "ported" vacum outlet on the carb, that's why you'd not be getting full advance in top gear at WOT.

gsp · Jun 19, 2014

I would still advance the ignition timing to the point of pre ignition on the best fuel you have normal access to,,,

I always do this, BUT,,, I installed a high torque starter, some BIG battery cables and multiple block to frame ground straps to get it to start....

Your selection 35-320-8 grind XE264HR-12 is a nice cam,,, for manual transmission, higher idle speed

ford racing E or F, X, Z 303 cam is a good one

http://www.fordracingparts.com/parts/part_details.asp?PartKeyField=1329

ON EDIT:

I just realized you are not running a roller block????

You have a flat tappet cam in it?

As you stated: convert to roller: or find a roller block and bore to accept the pistons you have in this motor,, to get the power you want, you need to go roller

Here is a bad ass flat tappet,, valve to piston clearance might be a problem,,, will need high torque starter and some BIG battery cables

http://www.lunatipower.com/Product.aspx?id=5447&gid=284

or lower RPM

http://www.lunatipower.com/Product.aspx?id=2254&gid=284

full list:

http://www.lunatipower.com/ProductGroup.aspx?id=284&cid=68

grips · Jun 19, 2014

yankdownunder said:
The stock HO cam [202/202] is a good torque cam. May be a bit small for a 347, though. If the cam you have is best suited to a 360* single plane manifold, it is pretty big [bigger than a 202/202].
Do you have the vacuum advance plugged into the ported outlet in the carb?
The amount of advance can be adjusted [in Ford distributors and Mallory] via a allen wrench through the nipple on the distributor. Maybe not getting enough "total advance". This should be about 30*. Initial advance should be about 7*. I usually set initial advance with a vacum guage [disconnected and plugged vacum hose], adjust timing for highest vacum, then lightened springs in dist., with total advance adjusted via hex/allen screw in the hose nipple on the dist. Small Ford like LOTS of advance, cold thermostat/cold engine temp [160* summer], and rich mix.
You can adjust the vacum secondaries opening with lighter springs [lighter=faster] in the dashpot. I usually ended up with the lighter yellow on a 9.0+ cr small block with a vacum secondary 600 cfm Holley. Make sure you've got an anti-back fire check valve.
I much prefer the Weber designed 4bbl [Carter AFB and Edlebrock], they use weighted vanes for the secondaries. Easier to tune, better power, better fuel economy...
Even a semi stocker cam should pull more than 85.
Valve lash [preload for hydraulic lifters], may be valve float?
Get engine to idle at lowest RPM, warmed up, adjust timing for smoothest/lowest idle. Shut off engine, loosen the valve cover bolts. Start engine, remove valve cover, loosen rocker nut til you hear a "CLACK-CLACK", then tighten 1/2 turn. This is for adjustable rockers.
That's all I can think of. Probably in the "total advance" or not ported vacum as you'd be near zero vacum at WOT in 5th. If the vacum hose is not to the "ported" vacum outlet on the carb, that's why you'd not be getting full advance in top gear at WOT.

gsp said:
I would still advance the ignition timing to the point of pre ignition on the best fuel you have normal access to,,,

I always do this, BUT,,, I installed a high torque starter, some BIG battery cables and multiple block to frame ground straps to get it to start....

Your selection 35-320-8 grind XE264HR-12 is a nice cam,,, for manual transmission, higher idle speed

ford racing E or F, X, Z 303 cam is a good one

http://www.fordracingparts.com/parts/part_details.asp?PartKeyField=1329

ON EDIT:

I just realized you are not running a roller block????

You have a flat tappet cam in it?

As you stated: convert to roller: or find a roller block and bore to accept the pistons you have in this motor,, to get the power you want, you need to go roller

Here is a bad ass flat tappet,, valve to piston clearance might be a problem,,, will need high torque starter and some BIG battery cables

http://www.lunatipower.com/Product.aspx?id=5447&gid=284

or lower RPM

http://www.lunatipower.com/Product.aspx?id=2254&gid=284

full list:

http://www.lunatipower.com/ProductGroup.aspx?id=284&cid=68

Thanks for all the advice going to install the roller stick this weekend will re-check the timing.

grips · Jun 29, 2014

Installed a Comp Roller Cam 35-413-8. Yes it is a 351w cam, changed the firing order.
What a difference power is to the level that I expected right from the start.

Rowdy Fitzgerald · Jun 29, 2014

I've never heard of that before. What's the hp gain?

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yankdownunder · Jul 6, 2014

The 351-HO firing order thing:
The 351w had a revised [yet same cam dims] firing order that was supposed to change the crank loadings for the larger engine. The HO adopted this same firing order/cam order. The regular cam and the 351/HO cams ARE interchangable, only a rewire of the dist. cap is required to get them to run.
So, cam bearing size, lobe spacing, overall length, chain/gear... all the same. Only thing that I can think of, early cams may not work for FI, but later cam will work with carb.

gsp · Jul 8, 2014

Nice, My E303 cam is 351 firing order

302 Down On Power

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