any hamilton 12v head dyno results out there?

[kawi600]

Should be near stock when this is done. only thing Im not sure about is the lower valve faces versus the swirl reliefs I asked Zach to grind in.
It was 380 with .020 gasket and .015 off the head.

[kawi600]

Just heard back from the shop, looks like either the cam timing isnt right or the head was milled too much. Cant even bar the engine over with the head on.
It will probably be a couple weeks now till I can get some idea how this thing performs. =(

[DEZLFREK]

man thats a bummer.. hope you get it fugured out.. might have to go deaper with the valves or reliefs.. the math ended up not working on my motor also.. i had .090 in my last motor with the same cam and put .150 in these pistons with a .017 piston protrusion and also took .060 off the head so i had around .015 valve protrusion.. it turned over fine when i assembled the motor/head/cam but after my head gasket went all the intakes were hitting so thats why i had to go with a .020 head gasket.. just to make it fit/work..

[madmikeismad]

Make sure the cam in in right, I had mine in 180 out and I couldn't bar it over. At least thats what I'm assuming since I pulled it and turned it and put her back in and it worked

[kawi600]

yeah I emailed the shop last night and asked him to check timing. It could be keyed wrong, I dunno.
Its been running like crap for awhile, so it is possible.
I dont know how that happened with the valve protrusion if its not cam timing.. since the valvetrain is all hamilton and the piston protrusion was at .023 which is within stock spec.
Im guessing there was a miscommunication somewhere.
So if it is the head, I can recut the seats a little deeper for stock protrusion and feel safe again, lol. Just need to shim the springs.

[kawi600]

Starting to sound like there was some confusion with the valves, who knows. Anyhow its a good thing since zach has some updated valves, with dry lube coating on the stems to help when installers forget assy lube. Hes sending me a set overnight.
Id love to coat these pistons with ceramic tops and DLC on the skirts.. if I ever have them out. Worked real nice on my last bike build and I beat the snot out of that thing.

[Lostnwalmart]

Forgot lube on the valves? thats like engine building 101

[kawi600]

Originally Posted by Lostnwalmart

Forgot lube on the valves? thats like engine building 101

too true.
though how can you prove if it wasnt lubed or if the guide was too tight? easy to forget something. so zach eats up all the returns which costs him pretty bad id imagine. so a little prevention goes a long way.

[getblown5.9]

check the gear on your crank...seen more than one of them now that have twisted on the crank and thrown crank vs cam timing way off.

[kawi600]

how easy is it to shear that dowel pin on the crank / gear? This things been 450hp or less and 3200 rpm max since I got it.

[kawi600]

Ok, latest is that the locating dowels were too small for the head and the valves were hitting the lip of the cylinders.
Shop has it all assembled but now hes told me the compression is exactly the same as before the swap at 380psi. I think stock is around 425-440 or so? Im building this for a DD / economy setup so I think compression is really important for this role.
Anyone else with the head that had the swirl reliefs done that could tell me what this did to your performance and economy versus stock?
Its gonna suck if this behaves just like it did before with the .020 gasket on there.

[Lostnwalmart]

Mine is getting 19 ish mpg with pretty heavy fueling but it's also a scsb (chopped 250 so not a huge difference in weight)

[kawi600]

What sort of fueling and air are you running? Im guessing that 19mpg is all highway? Hand-calculated or overhead?

[Lostnwalmart]

Hand calculated 5x20's maxed pump and 181's with a 75mm single. This is at 75 ish mph. I'll be getting a full tank trip this time for better results

[kawi600]

D'oh.. just missed that you put turbo info in there.
Hmm, well seeing that I do a lot of city driving (unfortunately) Im going to hold out and see what Zach says about compression.

[Lostnwalmart]

Yup, I came up and harassed you for the 30* intake, and you did everything but the eyebrows on the valves.

[kawi600]

Hmmm.. so you dont have the reliefs cut on the intakes? Just the 30* valve cut?
Who knows what it all does, lots going on in there. I may take Zach's advice and run it for a couple months to see what it does.
Truck has been down for like 6 weeks now and riding season is here. Need wheels to haul my dirtbikes.
Going to be looking into a supercharger later on anyhow. might work well with that setup for all I know.

[PASSENGER]

We've been screwing around with one of these heads, here are our results so far with the out of the box numbers and ported with the intake manifold removed. This is with the stock deck height and the supplied Hamilton valves. Work in progress.

[oldestof11]

Just a question, why do you measure the intake "flow" with vacuum??? Why not at a set pressure like what we see in our engines?

[SHughes]

Originally Posted by oldestof11

Just a question, why do you measure the intake "flow" with vacuum??? Why not at a set pressure like what we see in our engines?

That's how 99.99999% of flow benches operate. The cost of a positive pressure flow bench is both astronomical and very hard to come by. I don't even think manufactures have them. There are some home brewed ones out there though, that are terribly inaccurate/inconsistent.