Unless you're just chomping at the bit to run roller rockers the bolt-down ones work okay with hydraulic cams. Not having to spend much on the head is more for balancing, etc. on the bottom end.

 

I'm curious to see what you do Justin. I'm not diving as far yet..but ya never know when the day may need it! Heck..the 300 is a very good engine to do a first rebuild cuz it is so simple! Anyhoo..keep with the updates!

 

I found balancing to be inexpensive and a bargain. Since AB is now a master porter, I'm certain he is dying to port the head. I hope the cam experience did not sour him on aftermarket cams.

 

AB, apologies for interjecting, but what's involved in using stud mount rockers on your 85-ish cylinder head you have posted above? any benefits versus using the traditional 84 and below head?

 

Ive heard porting the head can hurt the low end torque of the engine due to the air traveling at lower velocities at low rpms..
However it does help with the high rpm power output

 

Yeah, my Dad told me about the ridge remover and said he had one I could've used. I guess I'll know next time. I didn't know there was a tool for such a thing. Oh well, it wasn't too bad.

The cam I bought was off of Craigslist. Someone had purchased it from Comp but never installed it. The box, however, looked pretty dated, so they probably had it sitting on a shelf for quite some time. I don't know if that've had anything to do with it though.

I hadn't thought about magnafluxing the block. It's probably a good security, especially since it's been bored over before.

The machinist I'm going to be using has been doing this for a good 30 years or more. I've worked with him before and I also liked that when I spoke with him about my current project, his response was, "Ahh, 300s. Good motors. I just got done finishing one up for another customer."

 

That's what I'm thinking. The head's pretty much done. I'll most likely take it down and have it looked over "just in case" but I don't think I'll be doing over-sized valves, roller rockers, etc. Most of the extra money will be going towards balancing the engine. I'm wanting glass smooth when it's done.
Over-sized valves would be fun, but I imagine it'll have a negative effect on gas mileage, and since the valves are new, it'd be hard to convince myself it needs them.

It's definitely a very easy engine to work on. I love it.

I'm still planning on an aftermarket cam, but I still say, the experience certainly has made me very nervous. The worst part is is when I've relayed the experience, every machinist I've spoken with told me there wasn't anything more I could have done correctly. I'd rather I did something wrong so I could remedy it! It just boiled down to "bad parts". Yikes.

From what I've heard/read, the pedestal rockers put less stress on the valve tips. They also require 0 adjustment. You just torque them down and you're done. The previous style was also a press in stud, so they could pull out under the right (wrong) conditions. Since I'm not going for an all out performance build, I don't think it's too big of an issue.

I can't remember the specifics on that, but I think that has more to do with enlarging the runners/port matching etc. Porting for flow only helps since you're just smoothing it out and removing any obstructions, which is mostly what I did.

 

That's good. Most of what I "know" comes from reading tech articles.. I'm trying to get well educated before I attempt my rebuild.
I've read that smoothing or polishing the intake ports also has a negative effect. Many of the little textured areas in there are meant to act like a golf ball surface creating less drag and also to help fuel evaporation that builds up in droplets.
I've also seen it when there are imperfections in the manifold from the casting process, in which case def grind them off
But this is all speculation.. Maybe someone with a degree in this sort of stuff will chime in to lay these theories to rest

 

If you do the oversize valves, get the new ones from SI valves. They have the proper Ford size valves. You just tell them the year of the head, and they will ship them out to you. Ck #'s on head to be safe. Ford changed v.length, so be sure.

And don't use the replacement studs from your machinist. Replace oem ones with ARP for sbc.

Good luck.

 

Hey Buddy!!! Hope you have as much fun as i did rebuilding mine!! Keep the Pictures coming brother!

 

AB quote:
From what I've heard/read, the pedestal rockers put less stress on the valve tips. They also require 0 adjustment. You just torque them down and you're done. The previous style was also a press in stud, so they could pull out under the right (wrong) conditions. Since I'm not going for an all out performance build, I don't think it's too big of an issue.

gotchya. so what are u planning for the rockers? pedestal or stud mount? and if its stud mount, what does all that entail? just threading in studs and its good?

 

About time you rebuilt this thing. The bearing were pretty well worn, but nothing stands out as unusual wear. The lower mains always wear more than the upper, as the lowers support the weight, and the uppers just tend to help guide the crank along.

Aftermarket cams are always a bit of a gamble. You did everything correctly, but still encountered problems. That was a simple case of of having something that was defective. Most likely, a lifter. Comp had issues with lifters in the past, you probably just happened to get one of those older kits.
Don't let it deter you from giving it another try. If you buy the cam kit new, do everything right again, and still have an issue, you may be able to get it replaced. Even stock replacement cams can suffer the same type failure, and they sure leave a lot to be desired as far as power/torque are concerned.

 

Are they really that poor? i imagine they were pretty bad back in the late 60's too then huh... I'll prolly have to look for a replacement as well

 

I started a porting thread on the FSP board and this is the answer I got when I worried about enlarging the ports too much and killing low end:

You are displacing 50 cid/cyl, drawing thru an inlet path of equal or smaller cross-section (and flow capability) area than the 289/302 (~37 cid/cyl) used in stock form. Making the port bigger should be the least of the worries. Even with the stock head thoroughly opened up and massaged, the 300 six combination is still awfully restricted.

FORDSIX PERFORMANCE • View topic - Some porting pics; any advice?

OTOH, unless the engine's turning 4,000+ rpm all the "extra" porting I did won't be that noticeable. At least that's been the case on the V8s I've fooled with.

The right compression ratio and the right cam will cure any low end problems.

 

I'm very impressed with the work you've done in that thread! I can only hope my hand is as steady with such tools... although i'll most likely be more subtle around the valve guides and not take as much away as you did. i dont need any cracks
so the area where the valve seats in the head, how do you know it's a proper seal all the way around without having it machined? or did you and i missed something..
(before you think i have know knowledge in areas such as these, i don't. but cant learn without asking dumb questions right?)
and what would the right compression ratio be for low end torque? (i plan on mating a 240 block to 300 internals, along with the 240 head creating, im told, higher compression. however i'm not sure how much more...)

any new updates AB?