My 968 engine build

speedysprocket · 12-04-2013, 05:08 PM

Broke the head on my 87 S, so I finally built my 968 engine for the car… What a long, tedious assembly! Pretty much stock build, all new bearing and seals, crank scraper and head has a valve job and the pockets were opened up.

alan6272 · alan6272's Garage

nice porting job did you do it?? looks great.

speedysprocket · 12-04-2013, 07:24 PM

No, local shop did the head work and honed the block. They specifically said it's not ported- these ports are massive as it is. They just "opened the pockets" up.

uvachief · uvachief's Garage

That's a massive engine. Let me know if you ever want to sell it!

will944 · will944's Garage

Beautiful. Who did the machine work?

CHICKS · 12-05-2013, 04:56 AM

Quote:

Originally Posted by speedysprocket

No, local shop did the head work and honed the block. They specifically said it's not ported- these ports are massive as it is. They just "opened the pockets" up.

How was the block honed?

CHICKS · 12-05-2013, 04:58 AM

Hopefully not like this: My 16v Engine Build

speedysprocket · 12-05-2013, 05:37 AM

It was honed properly. Abacas Racing in Virginia Beach did the work; they've done some 944 race engines in the past and were knowledgable. As for selling it- sorry. Need this for my daily driver after her engine broke. Plus I doubt I could get my money back out of it...

kwikt 911 · kwikt 911's Garage

Did you time your own cams?

speedysprocket · 12-05-2013, 02:50 PM

Yes. See the third picture...

kwikt 911 · kwikt 911's Garage

Thanks, found your thread on the "other" site.

speedysprocket · 12-05-2013, 03:34 PM

Haha, no worries!

kwikt 911 · kwikt 911's Garage

Do you have a close up shot of the dial indicator assembly extension.

speedysprocket · 12-06-2013, 04:51 AM

I bought it from Harbor Freight… It's a vice grip with a long, adjustable arm that the dial attaches to. I just clamped it to the block under the head and placed the dial where I needed it and locked the arm in place.

Lear35A · 12-06-2013, 05:35 AM

Quote:

Originally Posted by kwikt 911

Do you have a close up shot of the dial indicator assembly extension.

Here's a picture of my setup. I bolted a small steel plate to the block to support a magnetic base for each of the two indicators.

flash968 · 12-06-2013, 05:41 AM

obviously those are all shots speedy put up are BEFORE timing the cams, as the bolts that hold the exhaust cam are not in place.

there also needs to be a second mechanism for reading the relative position of the piston, as the timing marks are usually about 5-10 degrees off. i've never seen on yet that is bang on. it needs to be one such that you can rotate the engine a few times and see TDC as it comes around each time, and simultaneously read the lifter gauge.

lear's shot is correct

speedysprocket · 12-06-2013, 07:20 AM

I found TDC myself before even putting the head on, checked and rechecked, and made my own reference marks for it.

flash968 · 12-06-2013, 08:13 AM

well, i suppose that essentially does some of the same thing a degree wheel would do, except for not being able to set the cam at a specific degree of opening, which would be more accurate than the tappet measurement.

the only issue then would be any variance in the piston position, which occurs as you rotate the crank. even with a mark, as you "float" over TDC, the piston moves quite a bit, which you can clearly see with a gauge. it's almost impossible to mark the crank pulley or anything that small, and get it dead on. depending on the angle of viewing, it's very easy to be off a few degrees. that's why a large degree wheel is better. but, with a gauge, you know exactly where the piston is.

when doing my build, we had to use both to get it truly right. the differences due to the design made for some pretty large changes in cam locations. this could easily have made some large changes in power, had we not have gotten it right.

the engine will run almost anywhere, and i'm reasonably sure you will be able to drive just fine. it's all about how much power you want, and where.

speedysprocket · 12-06-2013, 10:25 AM

And I understand that. I don't have a laboratory nor the precise instruments to make it prefect. If I'm so inclined and have the time, I may attempt to vary cam timing in the spring maybe, and see what kind of changes my G-Tech can show me.

flash968 · 12-06-2013, 10:34 AM

yeah - it may not show up on the g-tech, but it will on the dyno.

as a note though, many shops don't time the cams. they just use the template and run with it, often just setting it in the middle of the slots. i guess they figure that it runs, and the owner will never know the difference. in most cases, they are probably right.

those of us who have been seeking every pony from the 968 do things a bit differently though.