Top end upgrade

[Grey owl]

So rather than a 347 I have decided a top end upgrade. Starting with a fairly mild Comp cam with lifters hardened steel push rods. Set of 190 cc aluminum heads with roller rockers. A low rise Aluminum intake with manual choke and 600 cfm 4bbl. Plus a set long tube headers. Should be a good start in waking up a stock 302

 

[fordguy]

Start with a roller block and never look back

 

[AZ73]

Your 190 cc heads would be great for a high RPM Mustang but you're going to be sacrificing low end torque. Too much flow. Without more specifics I would recommend 170's if you're running stock ~8:1 compression pistons.

 

[Grey owl]

The compression ratio is 9.5 :1 the combustion chambers 56cc. It also has 42-25 Hughes stall converter i am not concerned by slight loss in bottom end engine power. I do not use it off road at all in fact since I have owned it the hubs have never been locked, it doesn't get driven in winter, no towing, no trails, no mud etc. It's just a cruiser, grocery getter.

 

[Broncobowsher]

Small chambers.
I was thinking that your compression ratio was going to be garbage. That small of a chamber does make for some unicorn heads. Will really limit any future engine plans as well. Generally you will want a flat top piston and control compression ratio with camber size.
Before you buy the heads, get your old engine apart. Are you sure the bottom end is really up to it? Pretty common even on stock engines that a fresh top end will make the engine run good enough that the questionable bottom end decides it is time to exit the party. Are the cam bearings (as well as the bottom end bearings) still in good shape?

The last Ford V8 I was in only had 60k on it and I rolled in a fresh set of bearings (really should have had cam bearings as well). Got the leaks stopped and made it drivable enough to decide how I would really like to have the engine built. Wasn't a bad engine, just wasn't good enough to hop up without doing a lot more work in the engine.

 

[Grey owl]

Your 190 cc heads would be great for a high RPM Mustang but you're going to be sacrificing low end torque. Too much flow. Without more specifics I would recommend 170's if you're running stock ~8:1 compression pistons.

Small chambers.
I was thinking that your compression ratio was going to be garbage. That small of a chamber does make for some unicorn heads. Will really limit any future engine plans as well. Generally you will want a flat top piston and control compression ratio with camber size.
Before you buy the heads, get your old engine apart. Are you sure the bottom end is really up to it? Pretty common even on stock engines that a fresh top end will make the engine run good enough that the questionable bottom end decides it is time to exit the party. Are the cam bearings (as well as the bottom end bearings) still in good shape?

The last Ford V8 I was in only had 60k on it and I rolled in a fresh set of bearings (really should have had cam bearings as well). Got the leaks stopped and made it drivable enough to decide how I would really like to have the engine built. Wasn't a bad engine, just wasn't good enough to hop up without doing a lot more work in the engine.

 

[Grey owl]

Correction they are a Flo - tec head 180 cc with 58 cc chambers...Like I said I am more interested in mid range power. I have had a dozen or more 289s and 302s over the years and have ZERO concern about the bottom end handle a mild upgrade like this. Carefully matching the cam and converter is the key to any upgrade i am quite confident this will be a good combination for my needs.

 

[Grey owl]

I had this motor torn down this winter to freshen it and address leaks etc, i reassembled it adding the common stuff like new timing gears & chain, a new high volume oil pump. It's making 40+ lbs of oil pressure at idle..

 

[Jakedog]

The compression ratio is 9.5 :1 the combustion chambers 56cc. It also has 42-25 Hughes stall converter i am not concerned by slight loss in bottom end engine power. I do not use it off road at all in fact since I have owned it the hubs have never been locked, it doesn't get driven in winter, no towing, no trails, no mud etc. It's just a cruiser, grocery getter.

This was almost like watching a St. Jude's commercial.
My eyes teared up when I read the part about the hubs never being locked.
Poor little Bronco.

 

[DirtDonk]

Well, we can always go back to the owners manual instructions to lock the hubs in every now and then!
Even if it never sees any off-roading action, at least the front inner bits will stay lubricated and rust-free for the long haul.

It's not a bad practice for any of us, but especially for the street driven Broncos (which most are in fact) to lock the hubs now and then and drive it a bit.
I used to lock mine for a couple of days worth of commuting a month. And I wheeled it more than some.
Of course, that monthly practice turned into bi-monthly, then yearly, then semi-yearly, then came the "hmm, wonder when the last time those silly things were locked" kind of maintenance.

But at least a "now and then" practice will keep the tears at bay.

Paul

 

[Broncobowsher]

I had this motor torn down this winter to freshen it and address leaks etc, i reassembled it adding the common stuff like new timing gears & chain, a new high volume oil pump. It's making 40+ lbs of oil pressure at idle..

That sounds good. I was thinking you were dealing with an engine that had not been opened up since Reagan was prez. Try to fix a tired engine with speed parts.

 

[.94 OR]

These used to be a lot more reasonably priced.
https://www.summitracing.com/parts/edl-2027

 

[Grey owl]

Your 190 cc heads would be great for a high RPM Mustang but you're going to be sacrificing low end torque. Too much flow. Without more specifics I would recommend 170's if you're running stock ~8:1 compression pistons.

 

[Grey owl]

Well, we can always go back to the owners manual instructions to lock the hubs in every now and then!
Even if it never sees any off-roading action, at least the front inner bits will stay lubricated and rust-free for the long haul.

It's not a bad practice for any of us, but especially for the street driven Broncos (which most are in fact) to lock the hubs now and then and drive it a bit.
I used to lock mine for a couple of days worth of commuting a month. And I wheeled it more than some.
Of course, that monthly practice turned into bi-monthly, then yearly, then semi-yearly, then came the "hmm, wonder when the last time those silly things were locked" kind of maintenance.

But at least a "now and then" practice will keep the tears at bay.

Paul

¾

 

[Grey owl]

It's definitely a good idea for sure i drive mine about 2500 miles a year and will lock them in every once in a while just to keep them lubricated.

 

[Grey owl]

Small chambers.
I was thinking that your compression ratio was going to be garbage. That small of a chamber does make for some unicorn heads. Will really limit any future engine plans as well. Generally you will want a flat top piston and control compression ratio with camber size.
Before you buy the heads, get your old engine apart. Are you sure the bottom end is really up to it? Pretty common even on stock engines that a fresh top end will make the engine run good enough that the questionable bottom end decides it is time to exit the party. Are the cam bearings (as well as the bottom end bearings) still in good shape?

The last Ford V8 I was in only had 60k on it and I rolled in a fresh set of bearings (really should have had cam bearings as well). Got the leaks stopped and made it drivable enough to decide how I would really like to have the engine built. Wasn't a bad engine, just wasn't good enough to hop up without doing a lot more work in the engine.

I think adding a proper converter to the mix when using an automatic is the key for bottom end power. Just off idle a 302 is making 60 to 80 hp so there is not much power until the rpm comes up. The new converter technology gets the engine in the power band quicker and smoother . These little trucks have some weight so getting into the power band early is important. Losing some bottom end with higher flow heads is inevitable but a proper cam and LONG TUBE headers probably adds more than is lost with 180, 190 cc heads. And exhaust system that can scavenge the exhaust gases properly and work with the heads to create more cylinder volume and velocity. That's where the trade off occurs.
So saying that high flow heads hurt the bottom end may not be an accurate statement when considering the other modifications. You need that higher flow to make HP and torque. The heads are just one piece of the puzzle. But certainly adding high flow heads with stock exhaust manifolds, stock cam, and 2bbl carb will hurt bottom end.