Grassroots Motorsports

Register Log in to GRM
- Community

Birthdays
Recently on the Classic Motorsports forums

Subscribe get a full year for only $23.95 Sample Free Test Drive—no strings attached

Login to post Forums » Grassroots Motorsports » What cam for my early bronco?

Feb. 2, 2012 9:18 p.m. hobiercr HalfDork

In the middle of replacing a leaky intake manifold gasket on my '77 Bronco I have determined that I probably have a blown head gasket. Lots of compression in the coolant system even with no heat built (and no thermostat). Oh well, just one (2) more things to take off. While I've got the heads off I figure I'll finally get around to put a cam in the motor, I'm just not sure what to use.

The specs: Early 302 block (not 77 but not later than 85). Stock bore, , stock heads, etc., Edelbrock 289 performer intake, Edelbrock 1406 (600 cfm) carb, Headers, MSD dizzy and 6AL

I've had a recommendation from a local shop friend to use the ford motorsports x303 cam but there is a FM A351 cam on the local CL boards for $40 with lifters that appeals to my cheap side. Any suggestions on these or other options?

I have the card tuning kit so dialing in the a/f mixture shouldn't be too bad.
Feb. 2, 2012 9:55 p.m. a401cj Reader

my advice is run away from those that advertise X more horsepower over stock. Unless you're racing or mud bogging you'll be a lot happier with an "RV" type cam that may even produce less "peak" HP than stock. It'll make more power under the curve and that's what you'll feel when you press the skinny pedal
Feb. 3, 2012 1:23 a.m. pimpm3 Reader

I will second the "RV" cam. If I ever decide to do a cam on my 76 that is the route I will go.

Do you have any pictures of your rig? Here is my 76, pardon the dust ...
Feb. 3, 2012 7:39 a.m. Gearheadotaku SuperDork

I'm more of a GM guy, but I approve of the early Bronco.
Feb. 3, 2012 8:03 a.m. hobiercr HalfDork

a401cj wrote:

my advice is run away from those that advertise X more horsepower over stock. Unless you're racing or mud bogging you'll be a lot happier with an "RV" type cam that may even produce less "peak" HP than stock. It'll make more power under the curve and that's what you'll feel when you press the skinny pedal

Yeah, I'm not looking for massive HP. A better torque curve and more power is really the goal.

BTW, has anyone ever run a 351W cam in a 302? From what I've read you just have t change your timing to that of the 351W.
Feb. 3, 2012 8:08 a.m. hobiercr HalfDork

pimpm3 wrote:

Do you have any pictures of your rig?

This is the only one I have online right now. Need to take more.
Feb. 3, 2012 8:16 a.m. fasted58 SuperDork

Axle ratio, tire diameter, manual or auto/ stall converter... lotta variables. Cam mfg websites oughta get ya in the ballpark w/ their recommendations... then ya oughta call their tech line w/ your engine/ driveline specifics to clarify further.
Feb. 3, 2012 8:16 a.m. Greg Voth HalfDork

I have a cam and lifters for a 302 that you can have. It wont work in any of the HO 5.0 stuff we are running now.

They were originally in the Classic Motorsports Falcon but was taken out during break in because they thought it may be too large as the engine wasn't producing enough vacuum. Turned out to be a separate issue (gasket leak I believe). I don't know the specs of it aside from it being a crane.

Its in the box from the cam that replaced it which was milder.
Feb. 3, 2012 8:21 a.m. hobiercr HalfDork

fasted58 wrote:

Axle ratio, tire diameter, manual or auto/ stall converter... lotta variables. Cam mfg websites oughta get ya in the ballpark w/ their recommendations... then ya oughta call their tech line w/ your engine/ driveline specifics to clarify further.

3.50 gears, 31.5" tires, auto w/o stall converter. The variables makes finding the right one tough. I've got a call into my local speed shop to see what they say.
Feb. 3, 2012 8:24 a.m. hobiercr HalfDork

Greg Voth wrote:

I have a cam and lifters for a 302 that you can have. It wont work in any of the HO 5.0 stuff we are running now.

They were originally in the Classic Motorsports Falcon but was taken out during break in because they thought it may be too large as the engine wasn't producing enough vacuum. Turned out to be a separate issue (gasket leak I believe). I don't know the specs of it aside from it being a crane.

Its in the box from the cam that replaced it which was milder.

Greg, any way you can find out more info/specs/part number on the cam?
Feb. 3, 2012 8:58 a.m. oldtin SuperDork

Gratuitous hotlink of my 73.

Broncos are happier with low end torque like RV type cams. A ford X cam puts power in the upper rev range.

For Greg - I've got a spare ford motorsports X cam for a roller motor still in the box.
Feb. 3, 2012 9:13 a.m. hobiercr HalfDork

oldtin wrote:

Gratuitous hotlink of my 73.

Broncos are happier with low end torque like RV type cams. A ford X cam puts power in the upper rev range.

For Greg - I've got a spare ford motorsports X cam for a roller motor still in the box.

What cage is that and where did you find that top which I will now refer to as "the toupee"? Love the look of the flares smoothed in. Did you do that?
Feb. 3, 2012 9:26 a.m. Greg Voth HalfDork

In reply to hobiercr:

Ill pull it out of the attic and see if I can find anything.

In reply to oldtin:

Very interested!
Feb. 3, 2012 9:40 a.m. Greg Voth HalfDork

Just pulled the cam down. Its got some slight surface "rust" that I can almost rub off with my finger. Should be easily polished.

The only markings on it are "1064P" a "Y" and 2 "BB" markings.
Feb. 3, 2012 10:03 a.m. oldtin SuperDork

It's a fiberglass tub (I'm now pretty good at tracking down wiring ground faults) the flare is molded in - also has a larger rear wheel well than a stock tub. My "safari" top is just a stock top that's been cut up (there's usually a few free tops in the classifieds on classicbroncos.com). With a little bit of vinyl and some snaps it could be full weather protection. I welded in a 1x1 cross beam and just clamped it to the cage.

Speaking of the cage - it's a Bronco Bob family cage (same cage sold in the tom's bronco catalog - just cheaper)- I got the unwelded kit, then added extra sections for seat attachment, a harness bar and frame connectors so the cage ties in to the chassis.

edit - the hardcore offroad bronco crowd like the crab cages a little more than bob's - but with a few tweaks I don't think there's much structural difference (bob's are 2" x .125 DOM) - I think the crab cages are 1.75.
Feb. 3, 2012 10:09 a.m. hobiercr HalfDork

Greg Voth wrote:

Just pulled the cam down. Its got some slight surface "rust" that I can almost rub off with my finger. Should be easily polished.

The only markings on it are "1064P" a "Y" and 2 "BB" markings.

I'm guessing that is an Elgin E-1064-P Dur: 224/224 Adv Dur: 294/294 Lift: 510/510 Lobe Spread: 114

That cam could work well. It might be a little more angled towards upper end power than torque. What do you want for it? Still need my short trailer?
Feb. 3, 2012 10:13 a.m. ReverendDexter SuperDork

I'm thinking the stock cam would be best in a Bronco... I mean, it's not like you're out there tachin' the motor out all the time, right?
Feb. 3, 2012 10:15 a.m. jimbbski Reader

If the block you are using is older then 1985 then you can't use one of the new roller cams in that block. There are "retro-fit" roller lifters that can be used. These are hydraulic roller lifters with bars linking pairs of lifters. This is required as the older Windsor blocks can't be retro fitted with roller lifters, the "dog bones" and "spider bar" that are used on the OEM roller lifters 302's. The down side of using the retro-fit lifters is they are very expensive. The cheapest I found used when I looked was a bit under $400 and went up from there.

Stick with a flat tappet cam from any one of many cam grinders that offer "RV" or "High Torque" cams.

Visit here, lots of great info and advise.

http://www.ford-trucks.com/forums/index.php
Feb. 3, 2012 10:22 a.m. fasted58 SuperDork

maybe something like this in flat tappet

http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=790&sb=2
Feb. 3, 2012 11:08 a.m. monsterbronco New Reader

wow i wouldnt have guessed there would be this many early bronco owners on here!!! awesome!

I have 77 with glass tub and little of what remains from a rusted out 76.

Sadly all my bronco stuff is 500miles away at my moms house waiting for me to have time to spend on them.

here is my 77
Feb. 3, 2012 11:31 a.m. JFX001 SuperDork

I've had a '67, a '69 half-cab, and a '77 at the same time. Love the EB's.
Feb. 3, 2012 11:31 a.m. a401cj Reader

monsterbronco wrote:

wow i wouldnt have guessed there would be this many early bronco owners on here!!! awesome!

yeah I kind of forgot we weren't talking about a Jeep XJ
Feb. 3, 2012 11:37 a.m. alex SuperDork

You guys are making me jealous. I loves me some early Bronco.
Feb. 3, 2012 11:35 p.m. novaderrik Dork

hobiercr wrote:

a401cj wrote:

my advice is run away from those that advertise X more horsepower over stock. Unless you're racing or mud bogging you'll be a lot happier with an "RV" type cam that may even produce less "peak" HP than stock. It'll make more power under the curve and that's what you'll feel when you press the skinny pedal

Yeah, I'm not looking for massive HP. A better torque curve and more power is really the goal.

BTW, has anyone ever run a 351W cam in a 302? From what I've read you just have t change your timing to that of the 351W.

the 84 and later 302 HO's (and probably every other 302) used the 351W firing order.
March 22, 2012 9:57 a.m. hobiercr HalfDork

Quick update.

So I went with Comp Cams 31-234-3 Torque Cam and lifters. Adv Dur: 256/268 Dur @ .050" 212/218 V Lift: .477/.484 L Lift: .299/.303 RPM range: 1000-5200 L Sep: 110 deg

We were going to swap the cam with the block in the chassis but had to remove the front grille. Hmmm, after spinning one rusty grille retaining bolt up inside the fender we opted to just pull the block. We determined the heads needed a little work so I had a valve job done and the heads decked. They are back from the shop so we pulled the block Monday night. Drained the oil and it was goopy/nasty. We definitely had water getting into the oil. While it is out we will do a pan gasket, rear main and possibly a front tranny seal, oil pump, oil pump shaft, engine mounts.

Funny thing, though. We pulled the old cam last night and guess what? VERY similar to the new cam. Arghhhhhhh. Old cam is a Melling MTF1.

Adv Dur: 280/289 Dur @ .050" 214/204 V Lift: .448/.472 L Lift: ?? RPM range: 1000-4500 L Sep: 112 deg

Meet the new boss, same as the old boss?

What really sucks is that the old cam looks great as did the lifters. Oh well, that teaches me to "upgrade" before I know what I already have.

You'll need to log in to post.