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351w engine build advice

4K views 26 replies 16 participants last post by  Grimbrand 
#1 ·
I picked up a used 95 351w and just finished the teardown. Basically, it needs a complete rebuild. The heads are junk, the cylinders are wavy, not much can be saved.
End goal is a torqey (sp?) street motor. 400hp at the crank would be more than adequate. A couple questions:
1. rebuild bottom end myself or just buy a finished short block? I haven't priced machine work since the 90's so which would be cheaper? I'd like a 408, but bottom end budget is about $1000-$1500 total and honestly a 351 would be sufficient.
2. I want to make big power by 2000 rpm and be done by 5500. Would 170cc heads do that or should I step up to 190's? Budget for heads is also about $1000 so they'll be some Pro-Flo-GT4X chinese knock offs on there.
3. Edelbrock rpm or air gap rpm intake. Is there any difference or advantage at my power levels?
I'll get a cam recommendation from Comp because I'll be running a v6 torque converter in my 4r70w and don't know my head flow numbers yet.


Any help, especially on that bottom end stuff
 
#2 · (Edited)
Whether machining your current block is worth it is area dependent.

I know when I had my engine done, I would've been better off buying a shortblock, instead. The reputable shops charge much more than buying a shortblock, esp if you have to buy your core, etc.

Other than that, I clicked on this topic, because I was thinking about something similar and am interested in what others have to say.
 
#3 ·
You can probably throw another crank in there and get it to 393. I am going to go the 427 stroker route with a low compression build eventually put a power adder or two on it.
 
#5 ·
Why a V6 torque converter?
Because he's not aware that the V8 and V6 "high stall" 145 K factor stock converters are the same thing? For a higher stall stock style converter he'd actually want one for a Lincoln Mark 8/Mustang 4.6 which is an inch smaller diameter and has a 168 K factor.
Just me talking though.
 
#7 ·
Cop, have the connecting rods you already have reconned, and choose 302 pistons, and buy a 3.85 crank, Have the asembly balanced. That will give you a 393 if you go 030 over. Cheap, easy, and effective. LSG
I've heard about that. How much is balancing, or is that something I should just do myself with a scale?



The V6 converter came with the V6 transmission. It doesn't feel too loose or tight, so I'll re-use it unless I come across some reason I shouldn't.
 
#8 ·
Balancing should be around $200. Don't try to do it yourself with a scale. A special machine is required which the crank is installed, weights placed on rod throws and spun then weight taken or added to counter weight on crank. The 393 with Trick Flow 11r 190s and cam will produce plenty of torque. Keep an on going budget for rear tires!
 
#9 ·
Personally, if I were doing a 351w (not stroking), I'd try to find a good running roller motor out of a truck and not touch the shortblock. The factory 351w shortblock is part of what makes the 351w so good and economical for performance. I'd sell what you have to someone who does want to go 408 and try to find a decent runner.
 
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#10 ·
That was totally the plan. It was running before I pulled it, but it ran smoothly because it was evenly worn out. Now I've got it tore apart and putting it back together would cost me money in time and gaskets at the least.

I'm currently leaning towards throwing some bearing and rings in it after running one of those dingleberry honing tools on the cylinder walls.
 
#12 ·
Bump for any advice on heads port volume or intake.
For the intake, I'm leaning towards the Weiand Stealth because it's significantly cheaper than the RPM or RPM air-gap. I expect I won't be much different power wise to justify $100 more in price for the Edelbrock?
 
#14 ·
For heads you really can't go wrong with Twisted Wedge. 170's would be fine if you're looking at 2000-5500 rpm. Cam it properly and 190's would meet your goal as well. Don't worry about clearance as the cam that meets your goals will be small enough to not cause ptv issues. Having said that always check to verify clearance after installation.

Sent from my LG-D631 using Tapatalk
 
#18 ·
I bought a 96 351 out of an F-250 $400. Current build cost is $7500 ...
Holy cow, what are doing to that thing, stroking it? I've got my roller 5.8 short block about done and have like under $350 in it total so far. But then I'm not rebuilding it, just "freshening" it up. I think I spent more on new bearings than I did the actual engine.
 
#19 ·
I hope to stay away from $7500. Ive got $300 into buying it, probably $20 into cleaning supplies, $250 for a rebuild kit, and $50 for a hone tool and ring compressor tool.


I'm still leaning towards sending it out to be cleaned and have cam bearings and freeze plugs installed. That will probably be another $300.


I'll buy heads that accept factory valvetrain - $800
Intake - $250
oil pan - $50
dizzy - $50
flexplate - $50
headers - $250
cam - $200


Total should be $2550 for a rebuilt low compression aluminum head 351w. I sold my old spare 302 for 250 and I'm hoping to get at least 500 for the one I have in there so $1800 out of pocket.


I'll be keeping a lookout for used parts to save cash
 
#20 · (Edited)
#21 ·
I was thinking blueprint didn't have the best reputation around here, but I may be mistaken. No matter to me, I don't trust anyone I can afford to build an engine for me.

copracr's list gave me a mental itch to add mine up the same way. It would be good to keep in mind that my engine is a "let's do something with some of this junk laying around" project. And if/when it blows up it will be like "Oh darn, have to break out the REAL engine now." So my list should be fairly unique.

Heads. I bought some Canfield heads off a boy racer that upgraded for $400. Those are resting on this engine now but I think I will use some GT40P's instead. They came from a core engine I bought for $50. Probably use Alex's valve spring set for about $120. New seals, a little porting, cleanup, and lapping. Plus seals, call it $180.

intake. I've lost my mind and thought I'd blow the dust off my old VV carb. I found the original 2V intake off the engine that is currently in my '67 and was OEM in about a 1978 police car. I traded around so much I don't have a price to put on it. At one time I honestly thought I tossed it for scrap. No idea why I still have it.

oil pan. Swap meet $30. Blasted and repainted.

Distributor. Well, my brother in law gave me a dual point (Mallory, I think). No clue where it came from. I hope to swap the F4TE steel gear onto it. Haven't got there yet. If it won't new gears are $60 last I looked.

Flexplate. If I choose to use that old C6 that's been lurking in the back corner of my shop for 20 years then I have two or three flexplates that came from core engines I bought. If I go with the the other option, a T5, I'll need to buy a flywheel and clutch kit. That C6 has been calling to me though. (Use me! Abuse me! Throw me away.) I could use the room.

headers. I found some at a swap meet for $25. They've had some bashing where it's obvious they didn't fit around somebody's AOD but I can live with that. Big point is that they bolt right up to the P heads. Wish I knew who made them.

Cam. F4TE is in there now. Some people here won't shut up about "B" cams though so I might pop $200 for one of those.

Oil pump. Melling standard. Ebay $10+ $5 shipping. New in box.

Pump pickup. Rock Auto again. $12?

Timing set. Melling. Summit Racing.

Timing cover I had.

New Aluminum water pump. Ebay $20+free shipping.

Maybe I'll need new pushrods.

Intake and exhaust gaskets on clearance at RockAuto. Two sets of each for $16, so $8 in the exhaust and intakes for this engine.

FL1A-Walmart. $3?

Carburetor. One of the two VV's that have been hanging on the wall the last 15 years. Plus a rebuild kit.

Other misc, I don't know. Teflon rear main, timing cover gasket set, pan gasket, etc. Pretty sure I'll be in under a grand altogether.
 
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#24 ·
one_fast67-

I've wore out a couple 5.0's and they like to lose oil pressure from the worn out cam bearings. I don't know if 351's do the same but I'm basically doing what you said because I fear losing oil pressure there. I'm also also doing a whole rebuild kit with all new bearings and rings cause once I got it apart I saw a lot of copper on a few of the mains.
 
#27 · (Edited)
The 5.0 engine I bought from a big rebuilder had a 100k mile warranty on it. All the fancy stuff. Line bored with torque plates, the works. .030 over, new forged pistons, blah blah blah.

They did the things they said they'd do. But all the supporting stuff that they SHOULD have done - wasn't. When I first fired it up, I had several lifters sticking. They sent me more, and I put them in myself. The bottoms of the bores were razor sharp, because they didn't clean things up after the bore, and that tore up the piston skirts pretty bad. The bearings were shot by 10k miles. Balance was terrible. Then, through a sad mistake *I* made (pinched fuel rail using a big crescent wrench) the thing caught fire and sat for many years.

It's only now, after double-checking everything 'while it's out' and getting ready to make it right that I discovered all these problems. I think this motor would've been windowed by 20k miles, or at least in very serious need of help.

IMHO, it's not wrong to have someone else rebuild your engine, but it darn well better be someone within arm's reach, so they can be held accountable for their work - whether it's good OR bad.

Don't use some faceless company that cranks out hundreds of cookie-cutter rebuilds. It's a whole lot cheaper for them to crank out junk, and then never face the consequences because their motors are out of warranty before the real problems set in.
 
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