Looking for input. First V8 engine build. I've done quite a bit of reading, and this sounds like a low dollar setup that will meet my goals, but wanted to run it by you all. Sorry for the length, just trying to be thorough.

96' 351W going in 96' 4x4 F150, E4OD trans, 33" tires, 3.55:1 gears, and flatbed. Far from a "race truck" more like mountain toy. MAF & OBDII equipped. Looking for more low-mid range torque and ability to feed fuel with stock PCM & injectors. If I had to pick numbers, I'd say 400+ ft. lbs. and closer to 260-300hp.

Plan is:
-GT40P heads, gone through by machine shop.
-Stock roller cam.
-1.7 ratio roller rockers. This gives 0.449"intake/0.476"exhaust valve lift and 116.5 LSA.
-Long tube headers.
-5.0L upper intake and hogged out 5.8L lower to match with stock throttle bodies (as discussed in an ongoing thread of this forum).
-Compression ratio should be between 9.3-9.5:1 depending on how much the deck was blocked (stock head gasket thickness & 59cc CC).
-I have carbide burs, I'll try my hand at matching intake to heads, and headers to heads without going crazy.

I'm aware of header clearance issues. 90* wire boots, and header dimpling sound like a reasonable solution, short plugs if needed. I want the smaller combustion chambers of the P heads, and slightly better flow over the non-P heads.

For "maintenance" type stuff: new starter, water pump, oil pump, oil pump shaft, Cloyes roller timing set, new connecting rod nuts, clean injectors, and oil cooler delete. I have the correct distributor gear already.

Bottom end is stock. Machine shop boiled block, magnafluxed it, honed cylinders (they said they looked good), decked block to clean up head mating surfaces (I haven't measured piston deck clearance since), line honed main bores, replaced cam bearings, freeze plugs, boiled crank, polished it, and sized new bearings (standard crank bearings & 0.001" undersize mains).

Pistons checked out. Re-ring stock pistons after thorough cleaning. For other's knowledge, stock pistons are 20cc dish.

Is it a terrible idea to reuse: valve springs? I rarely see over 4000rpm and with my valve lift specs, should be no coil bind issues.

Re-use the roller lifters? They look pretty good, no play in the roller itself, and no scoring on the lifter body. Machine shop thought they looked ok to use.

Thanks for your input!

 

Oh, and quench...Sounds like about 0.035" minimum? Ford set it up at 0.039" from what I have read (zero piston deck clearance and 0.039" compressed head gaskets). So once I measure piston deck clearance, I'll be able to determine appropriate head gasket thickness. Sound right?

 

When I do my engine I'll replace springs with new due to the new one relitivly cheap at under $200 buck cheap insurance. Check out late model restoration.

 

Is damage pretty likely if a spring breaks? I do agree, they're not too expensive, I'm just wondering what areas I can save on. Not afraid of spending money wisely on this build though.

Whats the saying, "penny wise, dollar stupid"? Don't want to be that way. Or, "buy once, cry once" as opposed to buying twice..

 

A lot of cheaper (remanded) heads reuse valve springs and will shim up the weak ones to meet spec. I would not reuse the lifters. I know their a little pricey but it's worth not having to tear the engine back down in the future. I personally like to replace the valve springs simply because if one breaks it could drop a valve into the cylinder and cause all sorts of damage. When i was working at a friends shop a guy brought in a ranger with a 3.0 that was missing bad, after a compression check and pulling the head we found out it broke the spring and dropped a valve and it had snapped the stem, flipped around and stuck through the piston. That engine only had 130k. The piston is hanging on the wall at the shop with the valve still in it.

 

I purchased both of these to use with my rebuild. (not complete yet)

https://www.summitracing.com/parts/tfs-21400004-16

https://www.summitracing.com/parts/tfs-2500100

All new & not excessively expensive or too cheap. Crane makes a similar spring package upgrade, but no seals.

 

Good info, thanks.

That TFS springs upgrade has been on my mind a while. GT40P springs are, from what I've read, not very good springs. Going to good springs makes me want to step up the cam, because I can always upgrade the intake down the road for less work than a cam.

Conanski has recommended the 35-512-8 cam to others before 35-512-8 - Xtreme Energy? Computer Controlled Hydraulic Roller Camshafts (For 1992-02 Magnum Engines WITH 1.6:1 ROCKERS) . If I used that with 1.7:1 roller rockers, it gives 0.510" intake/exhaust. That works with the TFS springs. I've read the GT40 & GT40P heads are about maxed out for flow at 0.5" valve lift anyway (183intake/123exhaust CFM @ 0.4" valve lift, 185/126CFM @ 0.5" valve lift), so that seems like a good match. At the same time, because the heads don't increase in flow over 0.4" valve lift by much, that supports me being cheap & using the stock cam.

For reference:
Stock cam (I think this is correct): 256 intake/266 exhaust degree duration (advertised) Lift with 1.7 rockers: .449/.476, Lobe centerline angle is 116

35-512-8: 258 intake/264 exhaust degree duration. Lift with 1.7 rockers: 0.510/0.510, Lobe centerline angle is 114

I'm not convinced I'll get $280 worth of performance from the new cam. What do you guys think?

Currently thinking TFS springs (for reliability & the GT40P springs aren't known to be very good), new roller lifters, stock cam, and Crane 1.7:1 roller rockers.

 

A good cam will be noticeable over the factor one. Considering the similar duration of the cam your looking at it should behave some what like the original. The heads are where you'll notice a bump in power. But as far as the cam i think it would be a good choice. Personal giving the way ford designed the exhaust I like running a cam with a little larger lift on the exhaust than the intake. Getting exhaust out is just as important as getting the fresh charge in.

 

When you say the way ford built the exhaust, do you mean the exhaust ports of the heads or the manifolds and back?

I started putting the bottom end together tonight. All is going well. Cleaning the block was tedious. The machine shop had it pretty clean (said it was ready to assemble), but i ran nylon brushes and about a gallon of brake clean through the oil galleys anyway, and scrubbed the bores until a white cloth came out spotless. Plastigage shows between 0.001-0.0015" main bearing clearance and the crank turns nicely with mains torqued down. Slipped the old cam in too, it turns nice as well. Checked all ring gaps, all between 0.022-0.025". I'm cleaning pistons now.

 

The exhaust ports are pretty restrictive and wasn't a very performance minded design. Porting helps but not as much as most would like. Thats a little tight on the main bearings. I've always tried to get .003 clearance on the mains. I know some people will disagree but It's done me well. Are you going to use assembly lube on the bearings? Good luck!

 

Yep Permatex assembly lube in place. I figured engine oil would run out before I got it running. The machine shop recommended the 0.001" undersize main bearings (standard rod bearings). The guy has been in business since 73' with a good reputation so I trusted him. I've read that 0.001-0.003 will work on the mains, so I wasn't too concerned. Sounds like the larger main journals of the 351w help with making larger clearances work. From what I've read, Ford spec'd 0.0008"-0.0015" desirable & up to 0.0026" allowable on mains. Thanks for the luck!

 

I just looked in the manual and you are correct, .0008-.0015 is what is says. Seems awfully tight to me but thats ford spec. We've usually run .003 on the mains and .002 -.003 on the rods depending on what the use was. Which then again the guy that taught me that owned a racing shop for years and stayed busy so I figured it was good enough for me. As long as you ain't trying to spin it high rpm than I'd say go with the factory tolerance.

 

Oh and it also said you were allowed up to .0006 taper across the bearing. Didn't know if you seen any when you were checking

 

I didn't see much taper with plastigage. Not enough to "measure" without a good micrometer anyway. This truck won't see anything over 4500rpm. I've never seen the E4OD shift any later than that. I'll be checking rod bearing clearance once the pistons are all cleaned up.

 

No taper is great! Sounds like your well on your way to building a good reliable engine that should be within your horsepower goals. Just out of curiosity, i know you said your running 3:55gears and an e4od with 33" tires and was going to use it in the mountains. Have you thought about swapping the 3:55 out in the future for a lower ratio? It tends to help with the larger tires