351w into a coupe - building motor - question?

[chgovfk]

Hey all-

I have a 1993 4cyl mustang coupe - I'm putting a 1971 - 351w in it that's .30 over - new pistons / 4 valve reliefs /slight dome (but basically a flat top) / stock rods - and I have the new edelbrock E -Street heads - 60cc chamber / 170 cc intake - can handle anything less than a .550 lift - ....it will be converted to stick (TKO) ....and I can 'run' any rear end gear ratio I want - ....I just bought a 5.0 rear end out of junk yard -...anyway - the BIG question ....

I'm thinking either of (3) three cams or ?- I've been looking on all kinds of forums / called comp cams etc ....and the only thing I really learned - is that there all kinds of different ways to go - the guy at comp cams basically said an opinion on ea of these three - with running issues - I was wondering what you guys thought?


Comp cams said - Magnum 270 - rough idle (which is good) - good vacuum - less power - ticky lifters -

Thumper cam 35-600-4 (the smaller of the thumprs) - gd power / and TQ - and will sound the best - but no vacuum -

XE 268H - best TQ and power over all - a little ticky -

With the 'new' heads - and this being a street only car - I'm want it to be street- able - but what the heck.... why not make it sound lumpy and bad/azz......I'm thinking the magnum 280 ...my friend who's a ford tech and an engine builder wants me to go to the Ford racing 'letter' cams - I have the mutha thumps in my 07 gt and I love them - but they are more for sound (but have punch) - the project car will run pwr steering / brakes and air -.....I want to start building this puppy - anything you guys can help me with would be great .....

 

[chgovfk]

Bump....

 

[12Pack]

Sounds bad ass but me personaly id stay away from the letter cams. Check out comp cams.

 

[chgovfk]

Thx 12 pack - ya I'm thinking either the 280 magnum comp cam or the mutha thumpr - I've been on u tube looking / other forums - but the best advice was a guy who's running a 280 in a 351w - he saying that it's good - w/good vaccum ....and since it''s like some mystery on picking one - if it doesn't work out I'll just 'pull' it and try something else - ....

 

[strtrcr50]

If it were me, and I didn't know what cam I wanted, I'd call Rick at RNH performance. He is a member on this site, and an engine builder. If I wasn't happy with his answer, I'd try Ed Curtis, tell him exactly what I was running and wanted and price out a custom cam. I certainly wouldn't be shopping for a cam based on idle characteristics.

 

[hoopty5.0]

I'd read the threads about the E-Street heads on here BEFORE I bought them. Might save you alot of grief.

 

[chgovfk]

I read through the threads on the E streets - just now - but I think I'll be ok -I'm putting in a flat tappet cam - sounds like the issues are more for roller cams and roller lifters (spring breakage) - which I won't have - and since it's a street motor with a mild cam the springs should be ok ...I hope -

.....I acquired these heads in a sort of weird situation - I won/secured a $2.5MIL contract here at work - w/a main-stay client - my VP who's in charge of this client knows I'm a gear head and said he would let me charge a 'G' note on summit ( as a bonus) - for what ever I wanted - I was stuck - $1000 was my limit - so I tagged the E street heads - ....but in matter of fact I didn't pay anything for them - ....so for free .....what I can say.....he surprised me at my laptop - said bring it up ....I took his CC and went for it - I was planning on just getting the original iron heads re-done - I'm acutally a body and paint guy ...worked in a bod shop as a young kid.....

 

[ratio411]

Couple of points if I may...

*The 351 cubes will 'tame' a cam compared to a 302.
Reading the descriptions of the cams, I felt like you were describing how they'd act in a 302, not 351.
I have had 2 of those cams in a 302, and you described them dead on. In a 351, they'd be milder.

*Have you done any calculations on what your compression will be with those heads on a 351?
Dome pistons and 60cc chambers on a 351 will be a tight squeeze. I know we all love a hot engine, but do you really want to have to buy premium fuel every tank? And depending on what your compression really is, 93 may not be enough to keep it happy.

*The Magnum cams sound cool, but the 268, 270, and 280 are 40 year old designs.
You might look at a more modern series of cams. I know even Comp has several new families of cams out in the last 10 years. Even flat tappet...

Is your engine going to be carb'd or EFI?
What intake are you using?
(If it is going to be mild and carb'd, I like the Weiand Stealth or Torker myself.)
(Stealth will need a taller hood, Torker will go under the stocker)

Sounds like you need something between 220-230* @ .050" to me though. (280 Magnum is 230 with 110 lobe center.)
I wouldn't go over that though, you don't want the engine to be weak down low on the street.
With a manual tranny, you can push the lobe center down to the 108-110 range on the street and have a strong runner with a racy idle. (Auto trannys need 110-114 depending)

Did you tell us what your exhaust plans were?


Edit:
I zoned out on the "XE" before the 268 cam. I had the HE 268 in mind when I was saying it was a 40 yo design. The XEs are much more modern.

 

[ratio411]

Looked at your cam choices again...
I'd go with an XE, but maybe bump it up to the next grind.
I'll have to look up the specs, I'm curious.

 

[ratio411]

Tell us more about your driving habits and intent before we talk gearing.
Sounds like you want a strong street runner.
So we are narrowed down to 3.55 to 4.10 range.
Now you need to think about gas prices, exact cam you are going to use, and if you drive only a little of highway, or alot.
Not much highway, not worried about fuel cost, and bigger cam, that all equals 4.10.
If any of these are a concern, or you downsize cam (rpm), then you start shaving the number downward to 3.73 or 3.55.

 

[ratio411]

Oh, and make sure you hang on to the original heads.
Store them up for another project, or sell them.
The 69-74 Windsor heads are excellent SBF heads when ported.
They can outflow some of the aftermarket heads if done right.

I'll quit posting now!

 

[chgovfk]

No keep going...your making Great points - I have thought of some of these ....the great guy at my machine shop calculated about 10.4 or 10.5 to 1 ..and I ran it through a compression sheet (on-line through comp) and came right in the same area -
So 10.5 -
Carberated - 650 cfm (probably a holley ) electric choke
I was thinking the edlebrock 8121 dual plane ( looks like it's pretty common on the 351w's)
Probably shorties ( I live in AZ - emisiions ) w/an H-pipe and then switch it out with stock cats for E testing - or long tubes / with a high flow catted H - not to sure - what evers cheapest ....and I can dig up - but I'll need conversion's for the 351w -
but the exhaust will not be stock -
I don't care about gas prices - this won't be a everyday driver - very little highway - mostly around town on weekends - so a 4: 10 will probably go in

As for the cam - I really like the 268 XE ....all around good - but I have a gear drive going in - and I really would like a lumpy sound to go with it - I know you drag strip guys cringe ....but I don't have the room nor a trailer - nor a pick up to haul it to firebird dragstrip ....so I'm going for a really stock looking coupe - with a little lope in the motor - but mostly low end HP - but I want to run air/ pwr steer / pwr brakes w/no problems.....maybe your right
maybe an XE - 270 / 274 or a 280 ......thanks again for the help