Very nice.

Are you converting stud mount rockers? Roller rockers?

Was the stock flow measured with stock valves? If so, it would have been interesting to see what the gain was with larger valves alone, and then with the porting. But forget about that. It looks great! Good for you!

What is the cc of the chambers? What will be your dynamic cr?

Nice cam with an easy, gradual v. lift ramp.

So, the $1,000,000 question: After doing all that to improve the breathing of the engine, are you going to restrict the exhaust with a set of efi's?

 

Thanks K,

Yes, converting to screw in studs next. He's going to pull the studs, mill it down and tap them. I saw his work on someone else's there, and it looked great.
Roller rockers are a bit out of my budget, so as fun as those'd be, I'll pass on those for now.

The stock flow was measured with the larger valves alone, since it was ground for the larger valves before being sent off to the head shop. It'd definitely be interesting to have all three numbers to compare! But yeah, 211cfm to 241cfm with porting alone is pretty cool. I'm curious what the stock flow with the stock valve would be. I imagine it'd be close as only the opening was enlarged for the valve. Maybe 200 to 205cfm?

I believe he said the chambers were 74.4 before it was milled, so... maybe 75 right now after porting? We'll be shaving it down to around 72 or 73cc. Not very much, which will definitely be great for leaving plenty of meat on the head, should I ever need to work on it again.
As it sits, shaving to:
73cc = 8.92:1
72cc = 9.00:1

With the gradual lift on the cam, I'll shoot for the 9:1 since that calculates out to a pretty tame DCR of 7.06. I don't think I'll have much to worry about when it comes to pump gas.


As for the EFI vs. headers... It'll be sticking with EFI for now, since as is, I can simply drop the engine right in. Headers would require some exhaust work (as well as the headers themselves) and I'm just at the end of my budget for a while. That's not to say they won't make an appearance in the future.
I'll be dyno'ing it after it's all broken in, so it would definitely be interesting to have dyno numbers with EFI vs headers.

 

It is a great build, AB! I hope it is all you wish for, and more.

 

Nice work.
The stock valve flow probably topped out at or below .500 lift, so you could just plug in the .500 lift flow at the .550 and .600 lift points. Now you can begin to see why this engine responds so well to the head work you did.

Polishing the pistons - like polishing the chambers - improves the heat reflectivity. If more heat is kept in the chambers then more cylinder pressure is developed for the same amount of charge, resulting in greater power. One study I read from a Japanese researcher said gains were in the 1% to 2% range.
Reducing hot spots and the chance for preignition is another plus.

 

That makes sense on the piston polishing. Thanks for the info.



Does anyone have any recommendations on rocker arms? Are the stock ones just fine?

 

I am running oem rockers. I like roller rockers b/c the oem rockers don't give a true 1.6 ratio. That means you get less lift at the valve. Pmuller and FF confirmed that.

But the r.r.s coast so much. Comp makes a steel set with bearings at tip and stud, and they are only two hundred and something dollars. I'll pass along the part# if you would like. Pls., be sure to get ARP studs. Nothing less. I had a set of grade 8 ones sheer off, three of them.

BBC rockers work, as do Chevy I6 ones for the 250, 292. But I'd use the 1.6 ratio. Don't purchase some Chinese brand, or I'll have to cyber smack ya. The 1.7 and above ratios move the p.rod closer to the valve, and the head hole/slot needs to be machined accordingly. And ask FF about guide plates.


Good luck.

 

Oh, hey AB, I wanted to mention a nice upgrade you may already know about: Using the long plates Ford put around the lip of the oil pan on the efi years. They distribute the torque, like the plates around v.covers.

Cheers.

 

Thanks K, I'd be curious on the part number for those rockers. I could probably squeeze in a set of roller rockers if they don't cost too much. However, as far as I know, that requires modifying the valve cover. I don't have cutting/welding equipment to make my own valve cover, so that'd be another expenditure on top of that. But... It'd be nice.

Otherwise, I'll probably go with stock rocker arms, unless there's some Chevy I6 version that would work better with the adjustable studs I'm putting in.

Definitely ARP on the studs, and no worries about getting some knockoff Chinese brand. I'd rather quality parts over anything.

I've never seen or found any of those oil pan or valve cover rails. I'd love a set, so I may have to venture out again and see if I can find some. They'd definitely be great. I know I've already had to get rid of both a pan and valve cover because the areas around the bolts were so mushroomed.

 

AB--Here is a link for those rockers, $288, free shipping:
https://www.summitracing.com/int/par...6-12/overview/

For the v.cover, height is the issue. There is a guy on the other forum, cnc dude, I believe, who makes spacers to raise the v.c. PM me with an email and I'll send you a photo of a friend's roadster with the spacer on it. *Oh, come to think of it, he said he was going to start making cast v.covers too....

As much as I hate to admit it, he runs the efi manifolds, and calls them efi headers! We have an ongoing debate about that, lol. He's the one that told me about the pan tabs/plates.

 

Thanks for the link. Definitely some nice looking rocker arms.

A CNC'd spacer would definitely do the job nicely. That'd be sweet. My brother used to work at a place like that, and it was awesome just being able to design a part in CAD and then wait for something to go through the machine that had space left over and squeeze it in.

I'd be curious what his debate is on calling them headers. As far as I understand it, the idea of a header is to make the runner for every single cylinder the exact same length, hence all the crazy tubing.

 

I have the spacer from cnc-dude. It's pretty solid and well made. I have yet to install my new amped up head yet so I can't verify that it works, just that it's true and my rockers do clear upon test fitting everything on a table. I see no reason whatsoever that makes me think it won't work when installed and things are active under the cover.
I'll pm you his email address if you are interested.

Tomato, tomato maybe?

 

Those are 'tuned headers,' and there is, of course, an ongoing debate about them, and the pros and cons of tuned vs. non tuned.

 

Getting closer.

Went in today and caught him balancing the crank shaft.





We've also been looking for springs that will work with the oversized valves and cam, that have the right specs. He tracked down some that fit the bill, but none of his suppliers stock a set of 12 (only sets of 16). Summit has them, but he's a bit leery of them seeing as he said they get the bulk runoffs, instead of the quality parts.

https://www.summitracing.com/parts/crn-99838-12

 

That's the first time I've ever heard that. I've been buying parts from Summit Racing for around 20 years or so. And I've never had an issue with a parts quality.

 

Yeah, I get stuff from them all the time too.

Basically, what he said was if you can buy it directly from the manufacturer as a machine shop, you're more likely to get their highest quality stuff, whereas someplace like Summit is getting the bulk runs. Not saying that you're getting anything less, just the likelihood of a bum part can be higher, so he avoids it if he can.