Stocker

Change your timing belts people, or you will get owned.gif The prior owners of this car found out that the belt won't last much more than 165k miles.



This is part of my standard transmission swap, and I am having difficulty resisting the urge to make the engine breathe better. So...




The thing must not have been running fast... The pistons look good and the valves don't even all look bent. The ones that are, aren't bent much:




This is what the chambers look like. Big valves are intake, small are exhaust. ALL are pretty badly shrouded, and there is a cliff beside the exhaust valves.


Closeup of shrouding


So... here we go!

First question: how much do I take off to unshroud the valves? Should I take the ridges all the way down, or should I just smooth / make the angles less severe? I know not to mess with the quench area, but I'm thinking I should be okay taking a little relief right up to the edge of the head gasket on the sides.

And if I take too much material, well, this did come off a 1.8L engine, and I have the pistons...

How much material do I have to remove if I install the 1.8L pistons, in order to not raise my compression that much? I really really REALLY don't care to pay for premium pump gas, and constant octane booster addition is out of the question.

Lessee here, volume of the chamber, swept volume, volume of added dish to make the difference between 10:1 and 11:1, hmm...

Bullfrog

Very nice pics. fing02.gif Lots of detail.

Looks like you got off easy and can just replace the valves if you want. Perhaps you should replace the valves first and and make sure you can get it running before you start modding it...Be a waste to do all the work and and find its not going to run.

Stocker

LOL check my transmission swap thread for the reasons that this car is NEVER going to run again. Aside from the fact that it would mean changing 2 transmissions at the cost of an extra 15+ hours working in my driveway. I dunno. If the flexplate will work on the 1.8, it's theoretically possible, but right now it's not looking like it'd be worth all that effort just for maybe $1000. I'm pretty sure I can sell off at least what I paid for the car in parts, and if I break even and come out with a standard transmission, bored intake manifold and throttle body, and ported & polished head, I'm going to call that a good buy.

fing02.gif

The pics: I do photography for part of my job... to me, they are sub-par, and I blame the camera. The camera was free, though, so you won't hear me complaining too much!

edit: oh yeah, and my driver car just got a brand-new stock exhaust manifold and cat due to the manifold being cracked and replaced under warranty. So at the same time, I got a fresh, not-so-clogged catalytic converter. The manifold on the parts car is also cracked. 1 more reason not to rebuild the car. Maybe. We'll see. If I put the auto in a standard car, the harness is not so simple to correct, as it is when going from auto to standard.

AGreen

I'm still confused bro...

You're modding your car, you have a DD that is not this car (GOOD!!!) but you don't want to pay the extra $2.00 ($3.00 max) per fill up for 93 octane?

BTW, those pistons in that block look like ass. The cooling channels are all crapped up, and who knows what's up with (or in) the oil system... crazy.gif

You've got some options with this thing, dude. If it were me, I'd do like coal forge did with his and strip that sucka out, make it ultra light, build the motor and race it on the weekends. Then again, his is a DD

Stocker

any used piston is going to be ugly when it's pulled from a motor that had some use on it eh? Get the motor dipped and magnafluxed, blueprint, balance and boost. Fun. Just... fun for someone else.

What is the confusion? I am modding my DD because the parts fell in my lap, not because I set out to do a full-tilt build-up. ... and it looks like I can get a couple thousand dollars worth of mods done, by me, for almost a break-even. The mods are mostly because inefficiency pains me and if I can stamp it out (like smoothing a nasty valve throat area) I would like to if it's not too much trouble. And since I'm already in here...

If you want to hear the truly crazy long-term idea, it involves sectioning about 3 feet out of the back of the car. I know of a certain mechanic who builds rock crawlers called Crazy Dave, who would be giving an assist on that one. lmao.gif

The gas, just makes my eye twitch thinking about paying more for it. I've NEVER had a car that took 93, on purpose. When I see the price difference, I think I would get depressed remembering when I bought the cheap stuff, even if it's 10% more zoomy with the higher compression. I dunno though. I just might get bitten by the bug when all this stuff comes together. We'll see.

SO... how much to take away from around the valves... anyone?

Stocker

Google Singh Grooves and you will know why I REALLY want to do this.

I had never heard of the Singh grooves, but I looked into it when a serious hotrod magazine mentioned it like I should know what it was.

When you have EGTs down by 500 degrees, and 20%+ lower fuel consumption, a little more low-end torque, and your race engine can idle at 500RPM, well,

that there's something good.



Soooo... does anyone know how thick the head is at the quench pads?

01steve

oh? hmmm definately some good reading and possible project for my spare head!

Stocker

Update: pulled the vales. Exhaust valves are nasty and sooty, but look straight. 1/2 the intake valves are obviously, but not dramatically, bent. The intake runners are pretty clean except on the bottom, near the inlet, and one spot by the seat cup, where its REALLY rough. The exhaust ports are nasty, covered in soot. Red lines are about where the Singh grooves will be (straight in; the angles are due to the mouse I use, which my grubby-fingered kids also use)



The pockets where the seats are installed, all have sharp edges around them. Where the machining stops for the seat in the intake runner is very rough (can't tell in the exhaust till it's cleaned of all the soot).





There is some minor casting flash in the runners, intake and exhaust. The tops of all the runners on the intake side are clean. The bottoms, especially right by the inlet, have some obvious fuel/air dropout going on, and I'm sure the PVC oils are part of this mess too. I'll have to compare with the intake manifold to see what's going on here. Maybe smash some play-doh in between the two to see how they relate.




The exhaust side runners are surprisingly small, so that it squeezes my finger just to reach through there. Also, there is a 90 degree turn that could probably stand a little radiusing. Key to doing that is knowing how thick this part of the casting is. If I can't find that out, I'll just clean up the flash.

As far as the coolant channels, I think it was the shadows throwing you off... it's fresh & clean in there by the thermostat (didn't look close at the block yet). The oiled parts including the passages are orange, just like all the other Betas I've seen with their tops off...



The plan right now is to smooth out the ridges in the intake runners, knock the edges off around the seats, do the Singh grooves and maybe see what's up with the exhaust bend and intake dropout sections. I'm not too keen on gasket matching, not being convinced of the value of it. It looks like the bowls and chamber are where it's at.

Does anyone still have the photos Random posted of the cut-away runners when he cut a head in half?

Forgot to add:

to pull the valves, you need a large socket with an extension, and a hammer. Put the socket on the retainer and whack it. The exhaust valves will hit your bench, stop, and let the keepers go flying out. The intake valves have 1/2" or so to travel which would take a harder blow than I wanted to strike with the mallet... I folded up some cardboard and set it under each intake valve as I removed it, to give the valve something to stop against. Easy.

Loneshark

nice update ! how many miles were/are on the motor. my baby is running a little rough latley. looks like a timing belt change and possible after seeing all this, a new head PnP. I have about 110k miles.

Stocker

The donor has an ultra-low 165,000 miles. They had JUST put on a fresh set of Goodyears, plus new Gates hoses for the new all-metal radiator. Fresh parts for ME! Not to mention the 0-miles timing belt and tensioner... wink1.gif