trickedcarbine

Most air leaks aren't visible. The fact that a mostly stock motor needed a 350ish main with toomeys and a couple bolt ons, That tells me there was an air leak. If you did just the top end and it happened again, I would lean toward crank seals. I'm normally not one to preach the leak down as I'm advocate for checking the details twice and assembling once and that type of practice usually builds a solid engine assembly. However, it seems you guys are still trying to sort this out, so I reccomend tearing it all the way down. Split the cases and start over. Once you guys got it back together, a leak down would be wise.

The fella here who did a motor for us last season has a flow bench with smoke sticks. He likes to see how it all comes out of the ports and how/where the AFM actually mixes/collides. He is predominately a snowmobile guy but has been doing this since the 70's. He has messed with a lot of different set ups and has a good grasp of what works for certain types of layouts. Some stuff he jambs to the back of the cylinder and the boost port will kind of loft it up to the center of the dome. Other stuff he aims the transfers right toward the center of the dome, he even had an old GPX 670 motor with transfers set up like a whirl pool. He said he tested all the "turbo flow" ideas guys had in the 70's and 80's and it's definitely a gimmick. The turbo domes are junk, but there are some cranks on earlier motors that benefit from putting those little "turbo vanes" on them. He is always putting epoxy here and there filling little tight nooks and crannies in tight bends or angles. People always say he's killing volume, but the flow bench says otherwise and it allows you to visually see how the air flow actually improved. He likes velocity in a nice stream with low turbulence. Some people think they are adding velocity by adding turbulence, not always a winning idea. He's a pretty dominant fella in the sled game and I am grateful he has been willing to teach me some stuff. Reading books will only get you so far, after that it's up to you to put the time in. So when you find some old bastard who is willing to give ya a few short cuts, ya hang out and listen.

Not a bad idea. I intended on that when I planned on using them.

I think they like 10% of the shipped items value. $30 bucks? I'm off tomorrow, PM me your shipping info and I'll figure it out.

I bet that makes packaging it all in the yfz frame easier.

I was referring to actually watching how the ports actually flow. Lots of guys are trying to aim stuff but throwing smoke at it with pressure let's you actually see where, how, and how much volume you're moving to a particular point.

Kinda makes ya wonder if it's even phased right... Another concern. You mentioned your base gasket had quite the variance. I think you are saving the cylinder bores from uneven wear by fixing that alone. Maybe sleeper or Surf have other tips for this as well. But when I assemble a motor for good. I drop the jugs on, and only finger tighten them to where everythig makes contact with the gasket. Then put the head on and step torque it evenly to the jugs. Next, torque the accessable base nuts evenly. The nuts under the exhaust can be tricky but fall in to place if every thing else is torqued adequately.

If you haven't found brand new cases, take a peek at these. http://bansheehq.com/forums/index.php?/topic/183865-polished-cubsuper-cub-cases-no-chain-whack-300-shipped/#entry1751552

What kind of motor are you building?

It's amazing what all the little details add up to.

If you're willing to pay to insure it. Last time I sent shit up there it was a fucking fiasco and I just ate the loss even though they were tracked through Ottawa.

I bought these cases from a guy parting out a 421 cub a while back. But these are also bored for a super cub. I intended on trenching them for my 10mil, but decided to go Billit. Very clean OEM cases with a pretty decent polish. Bored to 80.962mm. Surfaces are in good shape. Transfers have been Port Matched to a Cub Cylinder. Outer rear studs have been replaced with Grade 8 studs to do away with the stud extensions for cub set ups. The aluminum plugs on the sprocket side are in there and the Case Saver comes with them. $300.00 Shipped. Sent from my iPhone using Tapatalk

Honestly, IMO (here comes the flame) the last HJR motor I saw that ran the way it should was Dajoger's. It was piloted to victory many years ago.

This in the hybrid?

Current deck height

Before ordering any domes if you have to.... You will wanna mock the cylinders up on whichever base gasket you decide to run. That way the cylinders are situated where they need to be so you can get an accurate deck height. (Distance between piston edge and cylinder deck) It's totally possible you can run a different base gasket and continue on with those domes(doubtful IMO), but I think everyone agrees that the gasket is the first thing that needs to be addressed. If it's already to thin to lower it, then you have a lot more work to do.

I'm aware you said that.... But I posted exactley why I said to check it. If the piston is already protruding in to the exhaust, then it wouldn't be a good idea to go messing with the base gasket and lowering the cylinder. But if the piston is below the exhaust, and you're not disturbing the piston/transfers much then you know you got some room to work with thinner base gaskets. You're correct about not knowing what he did with the exhaust, but I've seen a dune port and a couple MX/hardcore ports from him and they leveled out. So to me this set up is quirky from the second he said the piston is lower, as I've seen several of Kevin's set ups and they sat flush.

Measure the deck height, distance the piston is sitting under the exhaust before dissasembling. Measure the base gasket after tear down. Curious what it is smushed at.

Lmao! Friggin Christ!

Wise move.

Give these fellas a call http://www.provenforce.com/transfer_case/TC_ram_1500.html I believe the t case out of a v10 with a518 will work. Not a618.

Main thing is, they really aren't meant to be doing 70mph. The idea is, if you're able to do 70mph safely, you really don't need to be in 4x4.

Ok, if it were me. I'd pull the head and get some flexible feeler gauges in there to see how far down it is sitting. Say you get 10 thousandths to make the piston sit flush with the exhaust port. Taking that much out of the base gasket would not only make it perform better just by adjusting the ports, but then your squish would be pretty acceptable with 55-56 thou. What base gasket is in there anyway?

If you don't feel like pulling the head, pull a pipe off and rotate the motor over to BDC. See where the edge of the piston sits in relation to the bottom of the exhaust.

And the new BHQ slogan is born.