First time Porting.

[PRHeads]

The 1.6’s are usually the first thing to get changed on a 516 head.

Every set I’ve done always got the bigger valve.

 

[Runner71]

The 1.6’s are usually the first thing to get changed on a 516 head.

Every set I’ve done always got the bigger valve.

Well, it's alot to take in when trying to lear all the parameters of this Guess it's a trial and error until i tested it in the car, ofc with a video

 

[Cranky]

Hmm, it's pretty crisp on the throttle.. or was .. Does it have something to do with the 1.60 exhaust of the 516 head?

Small ports are most likely the most of it. Just doing a good bowl port job (pocket port) and blending it into the ports will wake up just about all of mom's heads.....and making sure the ports match with the intake is a good thing too along with at least going with the 1.74 valve.

 

[Runner71]

Just measured the exhaust valve, its 1.802" .. Make the other head, slap it togheter and take it for a ride and see how it moves i guess

 

[PRHeads]

Just measured the exhaust valve, its 1.802" .. Make the other head, slap it togheter and take it for a ride and see how it moves i guess

That’s pretty much it at this point.

 

[69a100]

Small ports are most likely the most of it. Just doing a good bowl port job (pocket port) and blending it into the ports will wake up just about all of mom's heads.....and making sure the ports match with the intake is a good thing too along with at least going with the 1.74 valve.

I have a set of 516's that I did the exactly that to and it really livened things up, and that's just on the exhaust end! Good Luck

 

[PRHeads]

Hmm, it's pretty crisp on the throttle.. or was .. Does it have something to do with the 1.60 exhaust of the 516 head?

Just measured the exhaust valve, its 1.802

Sounds like the crispy magic was not from a 1.60 exhaust valve in the heads.

 

[BSB67]

What will be the measurement to judge the benefit?

 

[PRHeads]

What will be the measurement to judge the benefit?

The length of the black marks?

 

[PRHeads]

When in doubt, I like to use a quality success-o-meter:

 

[BSB67]

The length of the black marks?

Exactly. Maybe a smaller cam then?

As you know, what you think the black marks and butt meter are telling may differ from reality. But then again, for some, the black marks and butt meter are all that matter.

 

[PRHeads]

Exactly. Maybe a smaller cam then?

As you know, what you think the black marks and butt meter are telling may differ from reality. But then again, for some, the black marks and butt meter are all that matter.

If you’re not going to the track....... if it “feels” faster....... that’s probably all that matters.
How would you know otherwise?

 

[BSB67]

....if it “feels” faster....... that’s probably all that matters.

Yep, I think that's what I was saying.

I would say that in this case, the OP might be looking for more usable rpm, which he might get if the heads were limiting.

 

[Runner71]

What will be the measurement to judge the benefit?

Thats a good question, i think my butt meter is 100% accurate Dont know how far away a flowbench is and if it's even something to do on a set off iron heads, mayby in educational purpose then. But for me it's to gain the last few hp thats in the build and try to find some power at higher rpm's, im pretty happy with the cam for a cruiser but could use some more between 3800-5500rpm when flooring it, i have no problems with blacklines, have more off a hooking issue so next season im going for streets slicks. All this "perfection" off the build/tuning has become a drug so i cant stop wrenching and try to learn more.

I think it's a combination off all things and that every engine want's different things. Would have been more interesting with some timeslips in glovebox to compare against

 

[PRHeads]

How about a few more details about the combo?

 

[Runner71]

Well it depends on the performance!

But anyway, making progress on what im trying for.
Lapped the valves and completed the first head!
Time consuming and keeps me busy eitherway

 

[PRHeads]

Since the exhaust valves are 1.81’s, are the intake valves still the stock 2.08” size, or have the heads had been upgraded to 2.14’s?

Looks like you’ve done some smoothing out of the bowls & runners compared to the previous pics.

 

[Runner71]

Since the exhaust valves are 1.81’s, are the intake valves still the stock 2.08” size, or have the heads had been upgraded to 2.14’s?

Looks like you’ve done some smoothing out of the bowls & runners compared to the previous pics.

Thank you for sharing the knowledge. I measured 2.137 so i guess 2.14 on intake.

Yes been smoothing it out a bit but havent going hardcore "behind" the valve bowl. Should i go for more or is it enough already? Haha mayby i'll check with the porting templates.

Fresh on intake and exhaust.
Ive tried to create a "wall" on the backside, it's been lowered but saved some meet and smooth it out to help steer the airflow to each side. Don't know if it's gonna work like intended but that's the plan

 

[Runner71]

 

[Runner71]

Oh well. That's my effort as porting goes. Fresh paint and order me some new valve stem seals then re-install valves,springs and so on. It's a long wait until spring is here for some test driving doe!