help me decide: 302 or 351

1slow95 · May 12, 2009

Black95GTS said:
I look at your combination and I don't think its a monster at all, I think its very well thought out, makes great power and torque, and uses quality parts. If you're doing an engine build and don't crack the 1rwhp per CI, its not a good build. If I did a 351 build I'd probably copy what you did, excepting I'd throw in a Gforce T5 instead of the TKO600.

Adam

It took me about 2 years of planning before I starting on my engine. It started out as just a simple H/C/I, then I decided to go with a new short block because my stock one had over 150k on it. Then it moved up to a 351 because the short block was about the same price as a 331. Then everyone said to go with a big stroker if I went 351, so that's what I did. I ended up with the power I wanted, but I also went about $4k over what I wanted to spend.

My point here is it sounds like The_Mustang doesn't want an "engine build" right now. A simple 351W swap will give a nice boost in power and torque, and the build can happen later.

1slow95 · May 12, 2009

Pokageek said:
Same thing here. LOTS of drive-ability issues that have been a PIA. The car had the best driveability with the XX (not going to say which ones..) heads and shorty headers.

I expect about = 500rwhp out of it this week on the Dyno. We'll see how close I can get.

What did you change to get to 500rwhp?

Venom351R · May 12, 2009

Low-5.0 said:
Low rpm bucking/surging, and the idle never was steady all the time. Since I installed the AEM EMS and switched from MAF to MAP it's much better, and my tune still needs a ton of work.

My compression should be around 10.5:1 or just a bit higher.

so its mostly a tune issue and not a combo issue?

Pokageek said:
Same thing here. LOTS of drive-ability issues that have been a PIA. The car had the best driveability with the XX (not going to say which ones..) heads and shorty headers.

I expect about = 500rwhp out of it this week on the Dyno. We'll see how close I can get.

why wont you say which heads? What ones are you using now?

Pokageek · May 12, 2009

The procomp heads gave it great driveability but a max of 35xrwp IIRC. I dont want to say the name so no one else will buy them and make the same rwhp mistake.

My car has a ton of blowby with the open breather system. Rick has seen cars pick up 30rw by going to some sort of vacuum type system he is putting on because the rings are allowed to seal. I am already near 460rwhp. Plus the tuner thinks they can get even more out of my car with the adj FPR that they just put on. All this, the pms, etc.. I should be close.

final5-0 · May 13, 2009

Low-5.0 said:
Low rpm bucking/surging, and the idle never was steady all the time. Since I installed the AEM EMS and switched from MAF to MAP it's much better, and my tune still needs a ton of work.

My compression should be around 10.5:1 or just a bit higher.

A couple of things here that needs to be seen IMHO

1) Mike has made progress on the tune

2) Mike is doing the tuning himself

I have no doubt things will get better as his tuning skills improve

Don't let anybody kid you

I ain't really all that hard to get spark and fuel optimized for WOT

Working out all the driveability bug a boos

That my friends Separates the Men from the Boys :Word:

Stay at it Mike ... You'll have that nice ride behaving in no time

Grady

Venom351R · May 14, 2009

pokageek and low5.0 what are you guys running for lumpy sticks? I know low5.0 has an FTI but can you tell me the specs? I currently have an FTI but am uncertian at this point if I want to keep it or go w/ a new grind.

1slow95 · May 14, 2009

.600/.608, 240*/248*, 114 LSA.

:OT:

Grady, maybe you can help me out with my tuning. I don't know what timing I should have for my lower load cells... The default tune that came with the AEM has it really low, like 28* at WOT and 32*-34* at the lowest load values, which I never see. I think I'm running somewhere between 27* and 30* right now at the load I see while cruising. I pic of a stock or tuned N/A timing table would be awesome.

Pokageek, when you say vacuum system are you talking about a vacuum pump? Or some type of evac system, like PCV? Let me know if it helps, I could probably use something like that on my car.

final5-0 · May 14, 2009

Low-5.0 said:
.600/.608, 240*/248*, 114 LSA.

Grady, maybe you can help me out with my tuning. I pic of a stock or tuned N/A timing table would be awesome.

Here you go my friend

A virgin or unmolested spark table

Grady

1slow95 · May 14, 2009

Awesome. Thanks!

It looks like I have too much timing at higher load in the 1000-2000 rpm range, and I need more timing in the lower load cells. My top row looks like load 0.4 in that pic.

final5-0 · May 14, 2009

Glad the pic can be of some help to ya Mike

I hosed around a good bit at low load driving conditions cause I had a
good bit of bucking and surging with my 109 lsa bump stick

I found too much spark would indeed make it worse
but
You just have to pull small amounts and test to see what works

I found I got a bit more stable conditions being a bit fat
as opposed to being a bit lean

Between what you discover on your own and what can be found on the
tuning forums ... You'll see trends which can help you to not waste
too much time

My downfall to all that tuning stuff was .........
I just had to see how close I could come to perfection

Grady

95Vert383AOD · May 14, 2009

BTW guys wasn't the Cobra R 300hp/ 365tq Flywheel numbers just like every other advertised power rating??? So realistically the 300hp Cobra R was more like 255-260hp at the wheels. Kinda like the 225hp foxes were really about 190hp at the wheels.

With that said, for the aftermarket available, if he only wants 250hp -300 at the wheels he can save himself the trouble of doing a 351 swap. Theres people getting 300hp to the wheels (NOT CRANK) with a properly built nonstroked 302!

If you're building a performance 351 i would be upset at any RWHP under 360.....And if you stroke it you better put down over 400hp before boost.

But i digress. if your goals are Cobra R power. Well you can have that in a 302 and save a few dollars and pounds in the process.

I would hate to see someone reverse engineer a 351 (based on available technology) to the point it made 302 power with all the H/C/I options available to make a 351 swap a true performer. Then well have to hear how you got beat at the track by someone in a Hyundai Genesis or WRX because it was making the same power or more than your oversized paperweight of a 351 that you basterdized into a 302 power range. Would be a waste IMHO

You want under 350RWhp as a goal (Thats 400+ Crank HP)...then don't bother with a 351 swap. Those cobra R's with the right intake, Heads and Cam had the potential of making 100hp more than what they were sold at. Ford just never decided to R&D into the heads and intake to do so. Seeing how the following year they ceased production of the pushrod engine in the mustang all together.

Remember guys...the Cobra R was amazing because the GT couldn't get over 200hp to the ground. But the Cobra R made a Whopping 60-70hp more!!!

99FiveOh · May 15, 2009

According to what I've read, the 95 R was under rated. Either way, I'm not just doing this for more power. I'm doing it because I want a more reliable block when I throw some boost into the mix.

And you cannot make 300 hp to the wheels with a 302 inexpensively! You'll need good aluminum heads (1000$ or more), then you have to get the proper cam, pushrods, springs, intake, etc...

I followed a couple stories where guys tried to reach the 300rwhp mark with GT40P's, not sure if they ever achieved it though.

1slow95 · May 15, 2009

final5-0 said:
Glad the pic can be of some help to ya Mike

I hosed around a good bit at low load driving conditions cause I had a
good bit of bucking and surging with my 109 lsa bump stick

I found too much spark would indeed make it worse
but
You just have to pull small amounts and test to see what works

I found I got a bit more stable conditions being a bit fat
as opposed to being a bit lean

Between what you discover on your own and what can be found on the
tuning forums ... You'll see trends which can help you to not waste
too much time

My downfall to all that tuning stuff was .........
I just had to see how close I could come to perfection

Grady

Yeah, I found the same thing with mine running pretty smooth the way it is right now. Problem is it's at 10.5 to 11 AFR. When I take fuel out it doesn't run very good at all. It looks like that's because I have the timing way to high at some loads. I've learned a lot about tuning over the last couple months, but I still feel like I have no idea what I'm doing.

Mark, I'm sorry for continuing the :OT: but nobody replied in my tuning thread.

99FiveOh · May 15, 2009

Nah, it's cool man. Something different than everyone telling me I'm an idiot for what I'm doing! lol

S351Saleen77 · May 15, 2009

The_Mustang said:
Nah, it's cool man. Something different than everyone telling me I'm an idiot for what I'm doing! lol

Your not an Idiot!!! You are doing the right thing asking....but this seems to be how the forums are. Ask a question and get many different opinions.

I say go for the 351 swap. With everything the same the 351 will have more power. Then as time and money allow buy your parts to make more power.

And when the 351W came out in 1969 it was offered in Mustangs. Shelby dropped the 302 option and the 351 was the standard small block. The 351C came along then the Mustang 2 which changed everything. So when the Fox's came out why Ford never put a 351W in beats me? It should have been an option at least.
So to me this whole "truck" engine thing is really kind of funny.....

99FiveOh · May 15, 2009

Well, I've decided to stay with the 351. I tallyed up all the cost and it won't be much of a difference after I sell off all my 302 stuff I have laying around.

That being said, I ripped off all the F150 crap from my motor and threw it on a stand. Pulled the water pump off and the balancer and that's as far as I got. I'll start a new "build" thread when the real progress starts.

Here's a couple pics of my new beast:

Filthy!

1slow95 · May 15, 2009

I wonder if your explorer upper intake will bolt up to the stock 351 lower?

final5-0 · May 15, 2009

I too think the 351 is the way to go Mark

You have the basic block in place and you can upgrade the rest
when funds are available

Grady

99FiveOh · May 15, 2009

No, the ports on the explorer intake are staggered while these ports on the lower are straight. I wish it could be done, would save me some cash! And there's no way I could have used the truck upper on my car, it'll would have stuck up a good 6" above the hood line!

help me decide: 302 or 351

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