earleys94gt
Active Member
I would think the E7's, even ported, would be too restrictive:shrugg:
A set of GT-40's, I think, would be a better choice.
A set of GT-40's, I think, would be a better choice.
Budget 351W swap/build thread
- Thread starter 99FiveOh
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BlackVert
15 Year Member
will it make more power than a 302? no doubt about it
will it make as much power NA as a hotrod 347? not even close
will it lose power NA in the upper rpm range? you bet
would gt-40s be worth it if you could find them cheap? i think so
with a blower at 15 psi, will it kick some serious butt and still be reliable? damn straight
would i go that route? sure, and i'd plan on upgrading the heads as funds became available
the more i think about what i did and everything i would do differently if i were doing it again, the more i like the idea of a lower compression engine with a blower. with a combo like that, cruising around town, it would have stock like drivability, have decent mpg, and i could use low octane gas, but when i opened it up, it would pull really hard until i decided to let up. and after all, you still have more cubes than a 347 and a block that is much stronger. after you upgrade the heads, intake and exhaust, those 347 boys won't be able to touch you
will it make as much power NA as a hotrod 347? not even close
will it lose power NA in the upper rpm range? you bet
would gt-40s be worth it if you could find them cheap? i think so
with a blower at 15 psi, will it kick some serious butt and still be reliable? damn straight
would i go that route? sure, and i'd plan on upgrading the heads as funds became available
the more i think about what i did and everything i would do differently if i were doing it again, the more i like the idea of a lower compression engine with a blower. with a combo like that, cruising around town, it would have stock like drivability, have decent mpg, and i could use low octane gas, but when i opened it up, it would pull really hard until i decided to let up. and after all, you still have more cubes than a 347 and a block that is much stronger. after you upgrade the heads, intake and exhaust, those 347 boys won't be able to touch you
Heres a link to my 351w build The_Mustang i've read all of your thread so far and if it was me to do again i would buy what you want to be happy with!Like you saying you where going to order or did but it fell threw with that POS typhon intake.I would go with the TFS or go and get a GT40 lightning intake.As far as your post with doing E7's on it with a typhon intake and boost,your gonna barley make more power over the same set up on a 302.A 351 is only 49 more cubic inches then a 302, that little amount of cubes isn't going to make that much difference! Epically if you take 351w heads off and put on tiny E7 302 heads! BlackVert i disagree with your last post,i doubt he'll kick the **** out of 347's with a 351w E7's typhon intake and S/C. My 351w 40 over made at the wheels 319/339 on a mustang dyno because of the small cam i f'd up and put in it. My motor also has 8.1 compression.http://www.stangnet.com/mustang-forums/751223-my-351-build-pics.html peace
john
john
nmcgrawj
Advanced Member
arent 351w heads really just 302 heads? The only 351w heads i've read that are worth a damn are the old D00E heads or whatever they are called. Even lightnings only got the gt40 heads....which are the same as what the cobra and explorer got.
For how cheap you can find gt40p heads, i say get those over e7s.
And one thing to remember, a stock rotating assembly from a 351w is going to be heavy. So even if you make more power, you could still be slower than a 302. Not saying i wouldnt go with a 351....just something to keep in mind.
For how cheap you can find gt40p heads, i say get those over e7s.
And one thing to remember, a stock rotating assembly from a 351w is going to be heavy. So even if you make more power, you could still be slower than a 302. Not saying i wouldnt go with a 351....just something to keep in mind.
That's probably the funniest thing I've read in a while! If that statement had any merit whatsoever, all these companies selling stroker kits would go out of business! There's no replacement for displacement. Think of a cylinder as a syringe and the intake port as the needle. If you replace the syringe with a larger one and leave the port(needle) the same, and give it the exact same pull, it's GOING to pull more volume in, physics says it must.
The point of a 351 was never about more power...maybe in the future but....having had a s/c'd 302 car and the power level being almost block splitting, I feared it more than I enjoyed it. Constantly worrying witch time I nailed it was going to be the last.
And since my motor is about ready to sign off anyway, I'm going to have to replace it. So I figure I could just replace it with a stock 351 and have a much stronger engine. Once it's in the car and everything is all set up, then I can start bolting on the goodies, but in the mean time I'll have a nice, reliable replacement engine. While it may not make much more power than a 302, I have a hunch that I'll gain quite a bit of torque, if nothing else.
BlackVert
15 Year Member
if you read my post again, you will (hopefully) notice that i didn't say this.
did i compare that setup with E7 heads to a 347? no
what did i say? "will it kick some serious butt and still be reliable?"
how did i answer my question? "damn straight" (meaning that i think it will)
did i compare the same theoretical 351 WITH UPGRADED HEADS and the SC to a 347? yes
sure, getting the best intake you can is a good idea, but let's remember that this is a budget build. let's also remember that forcing air through the intake has a tendency to lessen the differences between a good flowing NA intake and a poor flowing one.
BlackVert
15 Year Member
the complication here is that, sure, given enough time, it will draw in more air, but with the needle only being open for a certain amount of time, there is a limit to how much air will go through it during that time
then again, with a larger syringe, the vacuum that is created is stronger, so it should still draw in more air in the same amount of time than a smaller syringe would
now if you are forcing air through needle from the other side at the same time ...
This is exactly what I was thinking when I decided to build my 351 this way. Just look at the S351. It's intake wasn't anything special (a Cobra intake with a saleen plaque?) and it had....that's right, 302 heads(eddy performers). But it still managed to make in excess of 500 HP.
I'm gonna try it and if I am unhappy with the results I'll come on here and proclaim all the nay sayers... MASTER! :SNSign:
nmcgrawj
Advanced Member
At the end of the day, look at NA lightnings....they had gt40 heads on their 351. An e7 will make less HP.
But blown, you'll be able to make more HP then your car can handle. So build the foundation like u had been planning.
But blown, you'll be able to make more HP then your car can handle. So build the foundation like u had been planning.
That's probably the funniest thing I've read in a while! If that statement had any merit whatsoever, all these companies selling stroker kits would go out of business! There's no replacement for displacement. Think of a cylinder as a syringe and the intake port as the needle. If you replace the syringe with a larger one and leave the port(needle) the same, and give it the exact same pull, it's GOING to pull more volume in, physics says it must.
The point of a 351 was never about more power...maybe in the future but....having had a s/c'd 302 car and the power level being almost block splitting, I feared it more than I enjoyed it. Constantly worrying witch time I nailed it was going to be the last.
And since my motor is about ready to sign off anyway, I'm going to have to replace it. So I figure I could just replace it with a stock 351 and have a much stronger engine. Once it's in the car and everything is all set up, then I can start bolting on the goodies, but in the mean time I'll have a nice, reliable replacement engine. While it may not make much more power than a 302, I have a hunch that I'll gain quite a bit of torque, if nothing else.
what i ment by my cubes answer is,if you put 302 heads on a 351 you just restricted those cubes.if you leave the 351 heads then yes it will work out good.I looked at the stock heads off my 351 when i tore it apart and they were the same size as my GT40P's i had on my 302.If you take time and look hard enough a lighting intake can be had for cheap and is the same intake that is on the s351's/cobras, it's the GT40intake.peace
john
Correction accepted. I just dont want him to build something and make the same mistakes i made when i did my 351. What i should of done was install a larger cam,and flat top pistons.IF anything at the time a bigger cam! Yeah i have a 360 with H/C/I but theres quite a few 331,347's and SOME 302's making CLOSE TO the numbers i'm making cause of my poor dessions. peace
john
BlackVert
15 Year Member
i made more than a few mistakes on my build. some of them were really expensive mistakes too
I junked the heads that came off my 351W. The motor was from a 94 F150 and the ports were exactly like the E7 that are on my car now. I had a set of GT40's sitting right next to them for comparison and there was no comparison. Besides, about 4 intake bolts broke off in those heads so I said to hell with that!
I would really like to install a set of aluminums though due to the weight savings.
I would really like to install a set of aluminums though due to the weight savings.
Maybe I'll get a set of these: Edelbrock 5023 - Edelbrock E-Street Cylinder Heads - Overview - SummitRacing.com
It's nice to see Edelbrock fighting back against the japanese knock offs and offerin something American made for the same price. You know they probably don't make a lot of money selling these.
It's nice to see Edelbrock fighting back against the japanese knock offs and offerin something American made for the same price. You know they probably don't make a lot of money selling these.
BlackVert
15 Year Member
do you still have those gt40s? if so, why not use them?
that's $900+ you could save ...
Nope, sold em a while back. I regret it now because they were in such great shape. Most you see on ebay are all rusted up good! Now Xerxes on here is enjoying them. 
really???? valves everything are the same size as the E7's? Well then are GT40P heads bigger then E7's or GT40's? My P heads had bigger valves then E's peace
john
i made more than a few mistakes on my build. some of them were really expensive mistakes too
From the looks of your sig looks like you fixed it? I still need a cam then runnin a S475.I'm 99% done with the first part of my project now it's onto the turbo system peace
john
The GT40's were bigger than the heads that came on the 351. And of course they're bigger than E7's..lol
BlackVert
15 Year Member
well ... yes and no. it has been on the road a good bit, but now i'm having an issue with the transmission not going into reverse, so it is sitting againFrom the looks of your sig looks like you fixed it? I still need a cam then runnin a S475.I'm 99% done with the first part of my project now it's onto the turbo system. peace
john
too bad too because the fall in DC is perfect convertible weather. sigh
