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Mild 351 Build Opinions

33K views 166 replies 44 participants last post by  green monster 
#1 ·
I have searched and searched threads/posts but some final opinions on my possible build. Long story short my SAS once again has to be put on hold. I am in the middle of my paint/body work and have the front clip off. So I might as well and pull the engine to fix the oil pan and rear main leak. But why do that when I can freshen up my engine. Runs good with 188,000, just leaks fluid and would like a little more oomph. I need to keep cost down to because I am also doing the paint etc, so I figured on this: BBK under drive pulleys; GT40P heads; Edlebrock truck Performer lower/upper intake; stock cam; new oil pan/pump etc, water pump, 2 row radiator; freeze plugs and obviously gaskets.

I already have FMS headers, aftermarket Y pipe with single high flow cat and Magnaflow muffler. I figure as long as the compression and cylinder walls looks good I can squeeze another 20K miles or more until I have to bore her.

Maybe I can also get close to 300hp and some wanted Tq. I don't think I would be to far off but just probing your minds!

Thanks in advance! :beer
 
#39 ·
Spending that much on heads and intake and not buying a cam to take full advantage of the power potential of them is going to drive you crazy in the end. The camshaft is kind of like the brain of the engine. I would put a cam in and advance it 4 degrees to get the most torque possible as that is what we feel in these broncos more than horsepower....... PM sent
 
#42 · (Edited)
The camshaft is kind of like the brain of the engine.
It is the number one factor in where the power is on the RPM band, and it definitely should not be overlooked. But heads are where the power is.

I don't know how much you want to do, but when you remove the exh knots and slight blend to gasket the E7's flow and make the same power as any of the GT's.
Your gonna tell me you can port a set of E7TE heads that will match the flow of a set of Aluminum GT40-X heads in an afternoon? What about the differences in valve size?

Or are you just talking about the Iron production run models (GT40/GT40-P)
In that case I would agree, I have read articles about ported E7 heads with over sized valves out flowing iron GT40's, and doing so on the cheap.
:thumbup


There are some intake swap info out there too. I'm gona try using the 5.0 truck upper on the 5.8 lower.
Not gonna work.


but then will the rest of your truck hold it?
So far, So good :thumbup

Idk...up to you, I just see so many people come into the shop with mixed matched "500hp" engine builds that don't have the low end to break the boat out on plane. I'll do a dyno run and they have less power than the stock.
That's because they don't know how to build an engine for torque. It took me about a year of research to un-learn how to build an engine for a Mustang, and about another year to learn how to build an engine for a heavy truck. Then running dozens of simulations on DeskTop dyno to come up with my combination.
 
#40 ·
Just FYI....I picked up some very lightly used AFR185s for 1200 with scorpion roller rockers.

If you have time to wait, surf some forums and pickup something lightly used for cheap. Mine had dyno time only.
 
#41 ·
I don't know how much you want to do, but when you remove the exh knots and slight blend to gasket the E7's flow and make the same power as any of the GT's. IMO spending $1200 for 25hp when you can do it yourself in an afternoon isn't worth it.

There are some intake swap info out there too. I'm gona try using the 5.0 truck upper on the 5.8 lower. Figure if it don't work I'm only out acouple hours and $25 in gaskets. If it works I saved $600. Money isn't the main concern for me, I just like doing what they say that can't be done. (wow I watched to much Smokey and the Bandit huh?)

My point being building a "mild", .7-.9 hp per cubic inch is easy with a little work.
9-9.5 compression
Cam
mild head porting
shorty headers
intake, mod or new
spend time with cam and ign timing

Sure spending the money on the short block then $3000+ on aftermarket heads, intake, TB, air intake, high flow exhaust, upgraded ign, dyno tune to get you 1-1.1 hp per cubic inch would be nice but then will the reat of your truck hold it?

Idk...up to you, I just see so many people come into the shop with mixed matched "500hp" engine builds that don't have the low end to break the boat out on plane. I'll do a dyno run and they have less power than the stock.
 
#44 ·
Didn't want to quote your whole post but maybe alittle more than an afternoon but the answer is yes....been done many times, and noted in several fourms. They wont flow the same above .500 of lift but they are the same at .400. Doesn't matter what the head is made off other than your able to run .5 higher on the compression with alum.

Same with the intakes, been done and flows decent....better than stock. Noted on several fourms and builds.

I'm not knocking your build and glad it works for you, just saying there other options for an engine that peaks at 4500 rpms without breaking the bank.

Oh and my point with the boat reference was that a 12 sec car engine looks good on paper but don't do crap in the average boat or 4x4.
 
#45 ·
Didn't want to quote your whole post but maybe alittle more than an afternoon but the answer is yes....been done many times, and noted in several fourms. They wont flow the same above .500 of lift but they are the same at .400. Doesn't matter what the head is made off other than your able to run .5 higher on the compression with alum.
Can you point me to some information on this?


Same with the intakes, been done and flows decent....better than stock. Noted on several fourms and builds.
Same here, I would like to see an oval 351w truck lower successfully ported to match a rectangular 302 truck upper. Comparison flow numbers between the 302 lower and moded 351w lower would also be nice, but I do understand if they don't exist.

I do remember someone trying it once a long time ago. But IIRC the results where not the greatest in the world.

Oh and my point with the boat reference was that a 12 sec car engine looks good on paper but don't do crap in the average boat or 4x4.
That is absolutely correct.
But 12 second car engines are not what we do here.
 
#46 ·
I can't find the link but it shows all the ford heads, 351W 4bbl, Ported E7, GT40, P and X, acouple aftermarket. At .400 the ford heads were around 200 at .400 of lift.

Just saying a 325hp 5.8 can be done with a budget build and a little work. Only worth it doing it if you can do it your self tho. If you gotta pay labor then it would be cheaper to buy aftermarket heads and intake.
 
#47 ·
There are 2 or 3 threads on here about the intakes, and several on the mustang sites. Had the chart pulled up last night on the heads but it was on PFD and I didn't know how to copy and paste it to here. I'll try to post just the link.

I'll post some pics and keep you posted on the intake mod, I've got a 5.8 lower I'll hack it up and see how much metal is left. Looks like alot of metal has to be removed, and from what I read the lower is retricted in the runner towards the port so it would only be an improvement over stock. But good enough for a truck engine.
 
#48 ·
I found this doing a quick search.

Intake Flow @ 28" H20

.100" .200" .300" .400" .500"
GT-40P 61 128 169 195 196
GT-40 54 107 157 183 192
E7TE 59 114 144 156 156
'69 351W 52 103 149 174 183
289 50 97 127 156 165
GT-40 (Y303) 64 114 167 199 213
GT-40 (X303) 53 114 170 207 226


Exhaust Flow @ 28" H20

.100" .200" .300" .400" .500"
GT-40P 52 90 123 135 139
GT-40 47 94 119 128 128
E7TE 42 78 105 115 116
'69 351W 48 77 100 113 118
289 37 71 93 104 107
GT-40 (Y303) 52 98 128 137 134
GT-40 (X303) 50 106 139 153 161

Interesting
I concede E7's could be ported to keep up with "X" heads. In fact this company claims to do pretty much that.
http://powerheads.com/images/FLOW-TEST-289-302.gif
But that's with CNC porting and at $800.00 a pair exchanged.


toysforme1 said:
Just saying a 325hp 5.8 can be done with a budget build and a little work. Only worth it doing it if you can do it your self tho. If you gotta pay labor then it would be cheaper to buy aftermarket heads and intake.
It can, absolutely.
I just dont think the average builder is going to make a set of E7's flow as well as a set of "X" heads in an afternoon on his work bench using a dremmal. :toothless

That's all :thumbup
 
#50 ·
I'm doing a re-freshening/top end myself. Here's some of the major parts I'm using.

Crane 444232 cam. 114 degrees lobe separation and .448/.464 lift. SD friendly.

Edelbrock Performer Truck EFI intake

Ford Racing Turbo Swirl aluminum heads.
Combustion Chamber Volume (cc)58
Intake Runner Volume (cc)178cc
Exhaust Runner Volume (cc)62cc

I plan to run full length headers of some type, to a single 3" exhaust. From what I've read around here, and on ford-trucks.com, it seems to be a pretty standard/mild type of build. This + 4.56 gears should provide plenty of power to turn 33's or 35's. Hope I helped!
 
#51 ·
It's getting a little heated in here! I see this is bringing out some interesting view points and opinions.

Anyways after consideration of my budget, need and intent I think I will get rid of the smog crap, get a set of worked GT40P's and a cam to match it. Best bang for the buck and I have money left for other misc engine and body work. I will still be left with a decent improvement in HP/TQ and it won't be pissing coolant and oil everywhere.

I am looking some rebuilt and worked 40P's. Any ranking order/opinion of these three?
1. The earlier mentioned pair off Ebay for $500
2. A freshly rebuilt pair milled .030" 3 angle valve job, bowl blended new seals etc
brand new heads for $500.
3. A set with 4k miles on them, with upgraded FRRP spring kit for $220

I will be finishing pulling the engine tomorrow and start cracking her open to see what she looks like in the inside and start buying parts!

I will keep you posted as I progress on this and the body/paint.
 
#52 ·
Didnt have time to read through the whole thread.But it seems to me that running a stock cam with upgraded heads and intake limits your gains.I would look into maybe a reground cam that will be workable with the SD system but give you more lift.I didnt do it to mine and regret it and am looking into a good reground cam now for my roller 351w with the Fast EZ-Efi on it now.I will be able to run a larger cam than you will.But you can get some good gains still and make use of those better flowing heads and a intake.http://fullsizebronco.com/forum/showthread.php?t=128302&page=11 Look at post #204 I ported a stock intake and put a 60mm BBK TB on it.I gained about a 1,000 rpm over stock but not much power difference due to a stock cam limiting flow.I also have ALM. heads.So you can make some gains on the stock intake with some porting work.
 
#60 ·
its the way aluminum disapates heat . aluminum heads are great to cut some weight of the front but if your building hp you need compression to build heat to raise combustion temp . youll be able to run pump gas 10-11 to 1 comp.if you just bolt them on your better off porting the stock heads . http://speedtalk.com/forum/viewtopic.php?t=5973
if you need more info i have it.
Interesting.

From what I read in that thread if two heads are the same, and one is aluminum, the iron head will produce more HP at the same compression ratio.

But you wont "Loose" power by going from stock Iron to aftermarket aluminum at the same compression ratio.

I actually did not know that. I guess that's the reason engine simulation programs ask you what material your heads are made out of.

Ok, so what is the minimum rise in compression ratio to stave off this loss (Lack of gain) of power between the two materials. You said raising it to 10.5:1 is the minimum, but that thread said 1 point will do it.

Also, how does this affect torque? Most of us want to hit max torque at 2,000-3,500rpm depending on the build. And are more than willing to sacrifice HP to get more torque at a lower RPM.

How does raising timing affect this?

And finally, in regards to pump gas....you do mean 89 Octain regular, right?

Gack, I have to roller F4E whatever block.
It will at least be roller ready, but you will probably find a roller cam in there:thumbup
 
#59 ·
I should be able to get you some numbers on a good cam grind next week.The engine builder that I know likes using custom ground regrinds not only for cost but he uses them in his own stuff.He thinks he can come up with a good grind for me.He,s pretty sharp on that stuff.
 
#64 ·
Yogib, it would be interesting to hear what cam guy has and would like to keep posted on it.

I will have to get on a desktop dyno and play with numbers and such. But i think its definite on the GT40P's and maybe the stock roller cam. Still looking into the cam though.

The heads, with E truck performer upper/lower and with what I already have should be a marked improvement in all areas. Just have to do the EGR delete and smog pump removal with those heads. I will just pack them away incase I move somewhere with emission testing.

I have been sick all day and still haven't finished yanking the engine out, so off I go to see what I can do.
 
#77 ·
Yogib, it would be interesting to hear what cam guy has and would like to keep posted on it.

Ya I will do.I saw a chevy roller cam today that he regroud and rehardened.There like a 100 bucks for it not counting shipping.It looked very nice and well done.They all come with a new cam card of course.He hadnt got the 351w roller cam back yet so I will try and keep you informed.He could im sure grind you one to just about any spec you want to work with your SD system.I assume you have a roller block being as you have a later model 351w but if its not already a MAF setup then Problem is.If your block isnt already a roller block it probably wont work.On a non roller block the lobe has to be different so the roller lifter doesnt rise to far out of its bore and the oiler hole is exposed and you lose oil pressure.It just squirts oil into the lifter valley then on full lift.But I will find out more on that soon.If im wrong, and it wouldnt be the first time, could someone please correct me on that.Oh G M show us some pics if ya can of the build.
 
#66 ·
ok, sooo if you went a slightly different route...

balanced 393 assembly... $900
used GT40's...$500 (or DIY ported E7's and valve job $200)
BC upper intake adapter...$100
used mustang 5.0 upper intake...$50
boring and decking block...$350
cam and liftes....$250


thats 350hp for around $2000.
 
#69 ·
Agreed, I have ordered the Edlebrock truck upper lower intake. More money but easier install. I think it will work good with the GT40P heads too. by the way, those two bell housing bolts behind the intake suck! Just the motor mounts left and she is out
 
#72 ·
I have been searching the forum for different ways to use a mount point for lifting the engine out. The holes in the head which the A/C and power steering go into would be ok, but there sleeved in side and don't seem to sturdy to use. How bad would it be to use a ratchet strap and wrap in under and over the headers on each side, then a chain to the 2 hooks? There pretty dang thick hooks too?

Any other ideas/thoughts?
 
#74 ·
Well more changes to this master plan of confusion! So I have talking to guy who i can get AFR 165s shipped for $1000. I know there has been a debate about 165 vs 185's, but for my purpose I think 165's will be pretty good. Plus I can be legal and keep the emissions crap. I still have to get on a Desktop Dyno but have been to sick with double ear and respitory infection to get motivated.
 
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