Hey everyone, its been months since I been on here. The school semester is drawing to a close so I can fnally get back to my 82' F250 project. Last time I was on here I had discussed having a rear main seal leaking so I decided to pull the motor and try my hand at building a more beefed up version to go back in my mud toy. I took the motor down to the block. It was acid washed & magnafluxed, cylinders honed, new freeze plugs tapped in and cam bearings pressed in. and now it is sitting in my room to keep from oxidation getting to it. Over the last few months I have ordered some new parts after removing the pistons, 2 of them were cracked, the heads on them were beaten pretty badly so I think something must have fell into the cylinders. So here comes the questions. I have a list of all the parts I have ordered, and I would like some feedback on what else I should consider before reassembly. The parts list with all specs:

Summit Racing True Roller Timing Set:fficeffice" /><O></O>
Timing Chain Style: Double roller
Maximum Advance/Retard at Camshaft: 2 degree<O></O>
Maximum Advance/Retard at Crankshaft: 4 degree<O></O>
<O> </O>
FlowTech Headers:<O></O>
Primary Tube Diameter (in):1 1/2 in.<O></O>
Collector Attachment: 3-bolt flange<O></O>
Collector Diameter: 2.500 in.<O></O>
Tuned: No<O></O>
Primary Tube Gauge:1 8-gauge<O></O>
Flange Style: Standard<O></O>
Flange Thickness (in):5/16 in<O></O>
<O> </O>
Summit Racing Street&Strip Stage 1 Intake Manifold:<O></O>
Engine Block Style: Stock/OEM standard deck<O></O>
Intake Style: Dual plane<O></O>
Basic Operating RPM Range: Idle-6,000<O></O>
Intake Finish: Natural<O></O>
Intake Material: Aluminum<O></O>
EGR: No<O></O>
Notes: Manifold does not have rear water crossover passage<O></O>
<O> </O>
Summit Racing Street&Strip 600cfm Carburetor<O></O>
Fuel: Gasoline<O></O>
New or Remanufactured: New<O></O>
Number of Barrels: 4<O></O>
Carburetor Flange: Square bore<O></O>
Choke: Electric<O></O>
Secondary Type: Vacuum<O></O>
CFM: 600<O></O>
Fuel Inlet: Dual<O></O>
Primary Jet Size: 67<O></O>
Primary Power Valve (Hg): 6.5 Hg<O></O>
Primary Discharge Nozzle Size (in): 0.035 in.<O></O>
Secondary Jet Size: 73<O></O>
Carburetor Finish: Tumble polished<O></O>
Ford Kickdown: Yes<O></O>
Throttle Linkage Type: Universal<O></O>
Notes: Summit Racing recommends this part for single carbureted applications only<O></O>
<O> </O>
COMP Cams Thumpr Hydraulic Flat Tappet Cam and Lifter Kits<O></O>
Cam Style: Hydraulic flat tappet<O></O>
Basic Operating RPM Range: 2,000-5,800<O></O>
Intake Duration at 050 inch Lift: 227<O></O>
Exhaust Duration at 050 inch Lift: 241<O></O>
Duration at 050 inch Lift: 227 int./241 exh.<O></O>
Advertised Intake Duration: 279<O></O>
Advertised Exhaust Duration: 297<O></O>
Advertised Duration: 279 int./297 exh.<O></O>
Intake Valve Lift with Factory Rocker Arm Ratio: 0.490 in.<O></O>
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.475 in.<O></O>
Valve Lift with Factory Rocker Arm Ratio: 0.490 int./0.475 exh.<O></O>
Lobe Separation (degrees):107<O></O>
Grind Number: 279TH7<O></O>
Computer-Controlled Compatible: No<O></O>
Lifters Included: Yes<O></O>
Lifter Style: Hydraulic flat tappet<O></O>
Valve Springs Included: No<O></O>
Retainers Included: No<O></O>
Locks Included: No<O></O>
Valve Stem Seals Included: No<O></O>
Timing Chain and Gears Included: No<O></O>
Assembly Lubricant Included: Yes<O></O>
Pushrods Included: No<O></O>
Rocker Arms Included: No<O></O>
Gaskets Included: No<O></O>
Valve Springs Required: Yes<O></O>
<O>Federal Mogul Premium engine Rebuild Kit</O>
<O>Brand:Sealed Power

Manufacturer's Part Number:CSMHP806-000

Part Type:Engine Rebuild Kits

Product Line:Federal Mogul Premium Engine Rebuild Kits

Summit Racing Part Number:FEM-CSMHP806-000


Pistons Included:Yes

Piston Material:Hypereutectic aluminum

Piston Style:Flat top, with four valve reliefs

Piston Rings Included:Yes

Piston Ring Facing Material:Moly

Piston and Ring Oversize (in):Stock

Piston and Ring Oversize (mm):Stock

Rod Bearings Included:Yes

Rod Bearing Undersize (in):Stock

Rod Bearing Undersize (mm):Stock

Main Bearings Included:Yes

Main Bearing Undersize (in):Stock

Main Bearing Undersize (mm):Stock

Cam Bearings Included:Yes

Gaskets Included:Yes

Oil Pump Included:Yes

Oil Pump Volume:Standard-volume

Oil Pump Pressure:Standard-pressure

Oil Pump Driveshaft Included:No

Freeze Plugs Included:Yes

Camshaft Included:No

Lifters Included:No

Timing Chain and Gears Included:No

Assembly Lubricant Included:Yes

Plastigage Included:Yes

Quantity:Sold as a kit.

Notes:Approximate compression ratio 9.17:1 with a 63cc head. </O>
<O></O>
My questions:
Does everything seem to fit together so far? I got the cam in and realized I was not very well informed on duration, lift etc..
Should I have the heads reworked or order new ones?
The cam requires aftermarket valve springs, but should they be Single, 1.460 in. Outside Diameter, 328 lbs./in. Rate, 1.195 in. Coil Bind Height, or Single, 1.435 in. Outside Diameter, 330 lbs./in. Rate, 1.037 in. Coil Bind Height.
When adding these springs what else as far as head parts should be changed or upgraded (i.e. pushrods, rocker arms, valves etc)?
Electric or manual fuel pump?

Sorry this is alot its just the first time I have had a chance to get back into my project build and I'm excited. any feedback would be greatly appreciated.

 

Also, Should i have the rotating assembly balanced? It has the original crank, I should reuse it right? I have also gone with an aftermaket Superdut Truck clutch since its going to be in the mud. Should I buy new connecting rods or are the originals good to reuse. Pictures tomorrow, fixing to head to work.

 

The 351W has a good strong lower end. I would have the crankshaft checked out just like the block was. The rods need to be resized and get new ARP bolts. I would
have the reciprocating assembly balanced.

The cylinder heads will make the biggest power difference. I would recommend an
aftermarket cast iron heads that are assembled with the type valve springs you
need for your cam and have 2.02 and 1.60 valves. Summit, Jegs and RHS are all
good sources for these heads. Good luck with your engine.

 

You say it's going into a mud truck? Here's a very important question then. What kind of rpms do you think this engine will see?

That's going to have a big part in choosing parts, heads, etc..

 

That cam will have a good sound to it, but did you see the rpm range? You did good with the small carb and 0-up dual plane intake, but your cam is only good for 2000-up. You will have to wind this motor out to get it to go. If you mud with this thing and have big tires, this will mean at least a 4.11 rear or maybe even higher. Someone can probably plug the numbers in to see what's happening at 2000 rpm. What is your mph normally when spinning through the mud, keep the tires clean with rpms correct? Not your actual mph but what the speedo reads.

 

I'm thinking like Dave and probably 81 - too much cam. I would go to Comp Cams site and either use their on-line dyno tool or download their app and play with it. And, I'd be looking for a cam that comes in lower than 2K.

Also, when using their app don't just take their head #'s for gospel. IIRC, their head flow #'s are way too high for stock heads. Go look at Thumper's heads, read the spec's on them, and compare to CC's #'s. I was thinking I was going to have way more power than I really got because the head flow #'s in their program were way beyond what I had - even after I ported them.

 

Thanks to everyone for the replie, it means alot having other oinions from more qualified persons. This will be my irst mud toy project actually. I hve rode with a few friends and one of them had built a 302 motor and used this ame and recommended it to me. But from the opinions im getting it sounds to me like I shoul return the cam and ge one more of an idle-4,500 rpm range right?
Also for the heads, change out my heads instead of reusing the old ones if im reading right. Get the rotating assembly balanced. I thought I was going right with the top end but when I got to the cam I was unforsure what would be best performance wise for mud,and the guy who built the 302 said you normly rack the motor to high rpms when your in the mud so you should look for somethng at least starting out at 1,500 to 2,000rpms

 

With a little 302 and its short stroke you do have to rev it to get any torque. The 351 has a longer stroke and more torque at lower RPM. And, for a truck or mudder you need torque to turn the big tires. And, idle to 4500 seems a good choice to me.

As for the heads, it is up to how many dollars you have. Thumpers heads seem to me to be a good compromise - good flow at lower cost than aluminum heads. However, sometimes you can find heads on Craigslist. BUT, you do NOT want large port heads. They are for high RPM and will kill your low RPM torque. DEAD.

Or, you can use stock heads and maybe do a bit of port matching. However, I don't recommend spending much time doing home porting as I did that and then had the heads tested on a flow bench. I helped them, but not nearly as much as I expected. In fact, the guy that did the testing showed me that he could have gotten that much flow with a 3-angle valve job. So, if you don't have a lot of experience in porting I'd just do a simple cleanup and leave the porting to those who know what they are doing.

 

Now that's devotion!!



Heads, if you don't want to spend money on aftermarkets, look for a set with the E7TE casting, or pull a set of 302 heads off a V-8 Explorer, and just drill the bolt holes out to 1/2", and a good valve job.

Rod bolts, I recommend a set of ARP wave lock bolts. You probably don't need the pro series, just the entry level wave-locks. Your rods should work fine, just have them reconditioned.

Have the rotating assembly balanced. I'm assuming they should be able to hit a 1 or 2 gram balance.

Pistons, I'm not too fond of the Federal pistons. The engine is going to see some good abuse and I feel forged is more the way to go.

Looks good for the intake, timing chain, headers. Pushrods, rockers, valves should be good. When you get new valve springs (may want to call Summit tech line and have a chat with them on that), have them get you a new set of retainers and locks.

The carb sounds reasonable, but a 750 really wakes up a 351. Just sayin'. It's really up to you.


Seeing that you're mudding, and I don't know how serious of a mudder you are, you need some good low end grunt along with some higher revs. The intake looks good, maybe switch the cam out for an idle or 1500-5000 rpm one. You should never have to take that engine over the 4500 mark anyways. If the duration was kept down a little more, that will help you. High durations like to rev high. Look for a 270/280 or 280/290 max.

Here's a couple that look good for you to check:

COMP Cams Xtreme Energy Camshafts 35-238-3 - SummitRacing.com
COMP Cams Xtreme 4x4 Camshafts 35-235-3 - SummitRacing.com

 

There is nothing wrong with setting a engine up for rpms, as long as everything works together. A engine with a 2000-up rpm cam would have large valve heads for better breathing, and very strong bottom end to hold together, and more importantly, would need a stall converter if you are running a automatic tranny, and both a manual and automatic would need a gear change in the differentials. The gear change would let the engine rev up to it's designed powerband.

But a high revving engine is expensive to build. It takes a lot of force to stop the piston and change it's direction at high rpms, that's why the bottom end has to be strong.

 

Ok I talked to Sumit and returned the thumpr cam this morning. Im going with one of the two 81ChopTop recommended.

These are the new specs for it:

Brand:COMP Cams

Manufacturer's Part Number:CL35-235-3

Part Type:Camshaft and Lifter Kits

Product Line:COMP Cams Xtreme Energy 4x4 Cam and Lifter Kits

Summit Racing Part Number:CCA-CL35-235-3



UPC:036584040941

Cam Style:Hydraulic flat tappet

Basic Operating RPM Range:1,200-5,200

Intake Duration at 050 inch Lift:210

Exhaust Duration at 050 inch Lift:218

Duration at 050 inch Lift:210 int./218 exh.

Advertised Intake Duration:254

Advertised Exhaust Duration:262

Advertised Duration:254 int./262 exh.

Intake Valve Lift with Factory Rocker Arm Ratio:0.477 in.

Exhaust Valve Lift with Factory Rocker Arm Ratio:0.493 in.

Valve Lift with Factory Rocker Arm Ratio:0.477 int./0.493 exh.

Lobe Separation (degrees):111

Grind Number:FW X4 254H-11

Computer-Controlled Compatible:No

Lifters Included:Yes

Lifter Style:Hydraulic flat tappet

If i can find some gt40p heads from an explorer, aside from the valve job (3 angle) correct? woulld they be able to hold.
Im going to talk to their techs see if they can match me up with the correct valve springs, retainers etc. Also now going with hardened push rods, and im going to look into some good forged pistons. Im building on a budget so it may take me a couple months to get all the parts i need but some day it will be finished

 

Im trying to find a farily cheap engine rebuild kit 400-500 for bottom end with forged pistons but only supplier for engine rebuild kits through summit is federal mogul. Anyone have other possibilities?

 

Are you sure you want to use forged pistons? If you need the strength, ok, but they have to be set up a little sloppy in the cylinder bores, so they are noisy when the engine is first started in the morning(the engine will have a knock to it till it warms up). They have those hyperteutic(spelling) pistons that are supposed to be strong, and don't expand as much as the forged, so they can be run tighter in the cylinder bores.

You don't need hardened pushrods unless you are going to run guide plates. But converting the heads to an adjustable valve train and using guide plates would be a good thing. But here we go again with the Ford heads. They need a lot of work to get them in shape. Check how much it will cost you to have the heads machined for studs and guide plates versus a aftermarket head already done. And the aftermarket heads will have larger valves and better combustion chambers and already be modified for good flow.

 

That should be a good cam for your application. I ran their 252H and it had very strong torque from idle up.

And, I agree with Dave on the forged pistons. I'm running hypereutectic pistons and they are a very good piston for anything short of all-out racing.

Ditto what he said on the hardened pushrods - not needed w/o a guide plate. Put your money into the heads.

 

I ran that cam(254H11)in a 351w with Performer RPM heads 2.02 1.60,roller rockers,Stealth intake,Holley 650 vac. sec.shorty headers with a c6,stock converter and 4:10 gears.The engine was in a '83 E150 4x4 van that weighed ~5600 lbs and it was a huge improvement over the stock engine.That thing was an animal.It had power from idle to 5500 rpm.The heads made the biggest power improvement.As Gary said,you could find heads on Craigslist for a reasonable price.I got mine new in the boxes for 600.00.Before I sold the van I replaced the heads with ported E7's and noticed a big power loss.