Ryno's Cylinder head story.

[spiffy]

air cooled ranch

He knows his stuff could point you in the right direction for your needs.

[Ryno]

air cooled ranch

He knows his stuff could point you in the right direction for your needs.

Thank you again Spiffy. PM sent to ACR.

[Amskeptic]

big valves were stock for dual carbs, smaller valves were stock for FI.

Yep, FI wants velocity around the intake valve to help atomize the injector pulse.

Good lord, what was that spray-painted head with the vise-grip-installed valve guide? Ayeeeee.

As a general rule with dual carbs, I have been told that venturi diameter (36 in your case?) is a good determinant of correct intake valve size, i.e. don't exceed by a crazy amount or the air flow is going to drop to truly lazy and give your carbs trouble with spray.

As you look at upgrading, keep an eye on the whole combination. I wince when peoople start flinging specs at the wall (you might as well put in . . .) because it is all much more tightly interrelated. You want better torque? Displacement followed by stroke. You want better horsepower? Cam grind bigger valves matched carburetion and balancing for sure. Track down the whole system though. Exhaust needs to be looked at when horsepower is your goal. Great torque does not involve the exhaust system until the airflow has reached the pipes' flow limits. With a bus, torque is what lets you get moving and hang in 4th a little longer on the hill, horsepower is what gives you pull in 3rd gear at 60 mph.
Colin

[Ryno]

big valves were stock for dual carbs, smaller valves were stock for FI.

Yep, FI wants velocity around the intake valve to help atomize the injector pulse.

Good lord, what was that spray-painted head with the vise-grip-installed valve guide? Ayeeeee.

As a general rule with dual carbs, I have been told that venturi diameter (36 in your case?) is a good determinant of correct intake valve size, i.e. don't exceed by a crazy amount or the air flow is going to drop to truly lazy and give your carbs trouble with spray.

As you look at upgrading, keep an eye on the whole combination. I wince when peoople start flinging specs at the wall (you might as well put in . . .) because it is all much more tightly interrelated. You want better torque? Displacement followed by stroke. You want better horsepower? Cam grind bigger valves matched carburetion and balancing for sure. Track down the whole system though. Exhaust needs to be looked at when horsepower is your goal. Great torque does not involve the exhaust system until the airflow has reached the pipes' flow limits. With a bus, torque is what lets you get moving and hang in 4th a little longer on the hill, horsepower is what gives you pull in 3rd gear at 60 mph.
Colin

Thank you for your input Colin, I appreciate it. You as well vdubyah. That is not my spray painted head, that belongs to chris I believe.

My goal is really to get back to being able to jump in the bus and drive to a bitchin camping spot somewhere in Northern WI. Really the engine was running good until I discovered this. I think a good valve job and a cleanup is all we need then.

[CoPilot]

Prolly will do ya just fine then. I would check into some port work on any heads you end up getting, THAT will help you out. I have been hanging out at Rocky's shop and I have seen what the ports look like on brand new heads...YIKES. Just imagine a waterslide that had ridges and sharp bumps in it.....yeah, that is what gets smoothed and rounded out so the heads flow much more efficiently.

[spiffy]

Prolly will do ya just fine then. I would check into some port work on any heads you end up getting, THAT will help you out. I have been hanging out at Rocky's shop and I have seen what the ports look like on brand new heads...YIKES. Just imagine a waterslide that had ridges and sharp bumps in it.....yeah, that is what gets smoothed and rounded out so the heads flow much more efficiently.

MAN, the copilot has been absorbing all this engine build stuff

Hey copilot, log out when ya go would ya?

[airkooledchris]

that ugly head is the work of AVP, the same rebuilder that did Ryno's work unfortunately....

a closer look at their work:


as for the what changes get what results post Colin made, more torque is ALL I wish I had.

theoretically, if one were willing to sacrifice some (money? - longevity? must be something?), what sorts of changes would you go about making to an otherwise stock hydraulic FI 2.0 type4 motor to gain more torque?

I realize the answer will involve essentially rebuilding the motor, or at least dismantling it to the point where you have cracked the case back into two, and likely would never do this unless an actual rebuild was due anyway, but interested in knowing all the same given that the head work shown above is the timebomb currently in my vehicle.

[Ryno]

Prolly will do ya just fine then. I would check into some port work on any heads you end up getting, THAT will help you out. I have been hanging out at Rocky's shop and I have seen what the ports look like on brand new heads...YIKES. Just imagine a waterslide that had ridges and sharp bumps in it.....yeah, that is what gets smoothed and rounded out so the heads flow much more efficiently.

Great advice CoPilot. I will ask them about a port and polish instead of the bigger valves.

[spiffy]

ryno, I'll say this again.....do your research and decide what is best for you, don't accept advice without gaining the understanding behind it.

Search around and see what others have done, be careful not to step in the BS and watch out for the nut swingers that just spew what they have read.

[Ryno]

Thanks Spiffy. I am not a complete engine building novice. I have built two pretty excellent engines in the past.

They just were not air-cooled, that's all.

[spiffy]

Cool, sorry to get preachy.

[Ryno]

Cool, sorry to get preachy.

Ain't no thang. We all love this stuff!

[spiffy]

as far as more tq goes, yeah.... It costs money but that money buys you the longevity.

A new rampier cam would give you some more poop if ya found the right grind. Upping the stroke and bore a touch would be the next step if you wanted more. Then you compliment your entire induction/exhaust to optimize your gains while also helping the engine to be efficient. You don't have to buy that pompous dudes kits if you don't want to. When I rebuild my type 4 I wanna go up to a 2260cc engine.

Just depends on what you want out of it.

[airkooledchris]

A new rampier cam would give you some more poop if ya found the right grind. Upping the stroke and bore a touch would be the next step if you wanted more.
Just depends on what you want out of it.

WebCam makes a mild performance cam that uses hydraulic lifters still (though you have to use theirs to keep the warranty)
http://www.webcamshafts.com/pages/autom ... 3_734.html - is that about the route you would go to up the torque if you were going to?

There was stock, mild, and one other but the next up would require programmable fuel injection.

If new bone-stock from the factory gave you 101 ft lb at 3000 rpm's, would a simple cam change like the above really give you noticeably more torque, or is there more involved?

again, just curious. collecting data for an eventual rebuild so I don't have to make the next decision so quickly and on the spot. (like middle of camping season or something.)

[spiffy]

I would want hear from someone that has tried the combo first. To give you an idea of what a "jump" to a perf. Cam would be my (type1) webcam 218 has .12 more lift but -.08 on duration compared to a stock cam. I am making fairly major upgrades to the rest of the organism to play well with the ramp cam.

The 107i has .097 more lift and .031 more duration compared to stock. How that difference translates into changes elsewhere I have no idea. As a friend has pointed out this is where the accounting game begins, because each change effects something up or down stream which costs $$$.