Valve sizes ... you better be sitting down ... 1.88 1.50 ......
BUTTT excellent for the application
THOSE are the only specs that I KNOW .... I did measure the deck height of the piston ... the width and depth of the dish in the piston etc. I did write them down but I don’t have them in hand.
Yes there’s the hemi rod option ... and the 4.15 crank with the 383 forged flat tops but I don’t have the spec sheet.
BTW ... I still have a 220 Travco UP THERE !
With valves that small I can't imaging any concern of the sp2p intake being a bottleneck and causing any issues.
I had a deal worked out on a 320 Travco but it fell through. Really would love to find a big one as I plan to cross the country and live in it for months on end while doing so. I like the idea of starting out with a fiberglass body so I don't run into the typical water damage older rvs have.
Do you have any idea what rods are in the 413? What size rod bolts? I like the idea of a 1/2 rod bolt in a hemi rod, but I tend to want to overbuild stuff so I only have to do it once. I still love turning wrenches building engines on a stand, but the climbing in, out, under, and around to remove an engine or trans isn't easy on my old body anymore.
So the 320 Travco deal is totally dead ? There are lots of 270s out there but personally I’m not a fan of the sloped back - it KILLS inside living space.
The heads ? ... then consider the valve stem size on the exhaust valve - huge.
I sat down and did a whole lot of figuring and wrote it all down ... but that paperwork seems to be misplaced. I had also considered going the simple CUSTOM flat top piston route with a stock RB rod with a way higher CD.
IIRC - the cost was not that bad because it would be a very simple design
That particular travco deal is dead, but there will be another. Really just looking for mostly the shell anyways as I will go through the whole thing. Have thought about buying a later model totaled RV at the salvage auction to get the systems and interior to retrofit if I can get one on the cheap. My craziest thought is a travco with a slide out.
I am sure the valve stems are bigger in part to transfer heat out of the valve into the head. More surface area means greater heat transfer. Probably have a nice fat valve face to seat contact area as well like the marine engines.
Do the exhaust valve seats have hardened inserts? Does it have exhaust rotators on the springs?
Doing some math I think you are on to something that the 11 to 1 piston would work well, but I can't find an info on the dome size other than it is .063 in height. Anyone know what CC's that dome is?
Compression height to flat part of 11 to 1 being 2.111 makes it .029 out of the hole if the block were to spec. The run of the mill mopars I have built are always tall. Is the 413-3 closer to spec or similar to the others? In reality probably close to 0 deck or slightly above. Close enough to manage quench with head gasket thickness. Thinking I would like to get to 9 to 1 compression. With the quench set right it should run on pump gas without problems. Could always fill up with high test if needed when going through the mountains.
A concern I have is those sodium valves. Read where some old Ford engines that use them had problems with them breaking if the motor had sat for a while before use. Is that a common problem with all sodium valves, or just poor blue oval engineering?
