mark kibort

Well, after the votes came in, another race weekend where I got beat by a couple of cars with more hp, I decieded to pull the engine in the Al Holbert WR setting Racer.

After almost 7 full racing seasons, 7 professional races, and over 100 racing days, the old dependable engine #0004 is going have its block exchanged with a new stroker short block thanks to a huge donation by the RennList 928 community who generously donated near half of the total cost of the engine!
Thank you again fellow 928'ers for your support.

I got an early start on the car in the week by dropping the passenger side header, radiator and clutch out of the car. Bill showed up on Friday to help get things ready to pull the motor, and after a couple of hours, Scot showed up with the CT automotive Cherry Picker. a couple of hours later, it was yanked out of it's chassis.

WE even pulled it with the headers attached! See the picks below

The first picture, is Bill picking up a cigarette that was lodged in the new GT alternator, as well as all the stuff on the ground around him. I guess i need a little longer intake tube for the alternator that is fed from air in the headlight fender area.

mark kibort

Just kidding, we didnt pull the engine with the headers on, but it would have been a good April Fools joke. (almost like the Herr Kuhn story! )

Anyway, Saturday, i dug into the engine and it was a complete mess! runs great, but real dirty.

Sunday, i spent a few hours getting the electrical off the engine, as welll as the intake and gave the filthy thing a bath.

Picks below.

check out the misalignment of the timing tensioner. remember i use the older 84 pump and S4 tensioner, and i think the S4 tensioner roller. there is a little angle that i never really took note of before. notice how the belt rides off the tensioner roller by 1/4" or so.

Also , check out my timing on the pulleys. the passenger side is off a full half tooth! driver side looks good.

Found the reason for the recent overheating. that seal in the T-stat housing was cooked !! nothing left, so it will need to be replaced.

Also, the plugs all look good, and keep in mind, that this car just came off the race track and was loaded on a trailer. (unusual for me, but true)

also a quick shot of the holber engine serial number.

A glance into the heart of the Holbert engine. Looks like stock stuff from what i can tell. pistons look stock from the look of the long piston skirt, but we will know more this week.



Mk

Ispeed

Those motor mounts look collapsed. Most likely a squirter block engine; maybe why it has lasted so long without all the normal racer stuff (accusump, windage tray, scrapers)?

mark kibort

why use the old timing belt when you can use the new one? I dont understand?

any thoughts on getting a new flywheel sensor and new knock sensors. the insulation on the knock sensor wires are pretty cooked, but no wires are showing through.

Mk

Jadz928

Mark,
The old belt has stretched quite a bit and will make it easier to do the cam timing.

Re Sensors: If you have to ask, change 'em. This is your conscious telling you to do something you are supposed to do. Never leave a question go unaswered. I will invariably be the one to come back and bite you in the ***.

mark kibort

I see! I didnt realize that they would stretch so much.

easy enough, ill try it. Also, Ill recheck the cam timing after the new belt is on too.

as far as the pulley marks being so far off, any comments?? I mean, its so far off now, that im wondering if it would be better to be off in the advanced direction vs the retarded direction as it stands now. (if you look at the pick, you can see the passenger side pulley is off almost a full half tooth. ) I guess when i check the cam timing, it will determine if that is right or not, correct?
I guess the only thing here is the distance from the driver pulley to the passenger pulley via all the rollers and crank gears, is off. Or, the belt has stretched, right?

Mk

Bill Ball

The cold cam pulley tooth position relative to the TDC mark is determined soley by the belt. If it's a half tooth off, that's the best you can do with that belt. I'd rather use a Porsche (Gates) belt. I encountered excessive stretching with a Conti belt on my 89, so I am prejudiced. We can set the gears and cam timing with the new belt and then re-check at 1500 miles. Easy to do with the PorKen tool.

mark kibort

I guess it really doesnt matter unless it changes over time. It seems like it was off by almost this much from the start based on some pictures i did during the cam change a few years ago.

thanks! And THANKS for the help. Couldnt have done it without you!!

MK

mark kibort

Tuesday update:

spent from 8:30 to midnight pulling the timing belt set up and the heads and cams off.

Now, the only thing left is the oil pan and pick up stuff. I still dont know what thats going to look like, but the pistons look like stock S4, series 1. Lots and lots of carbon build up, i was surprised. Maybe Im running way too rich. could be part of the power loss issue, as the heads and gaskets look ok from what i can tell. checked the valve timing before i yanked the stuff out. driver side is a little too far advanced at more like 2.2mm vs the driver side of 2mm at 20 degrees ATDC . I have a little more repeatable measuring system now.

Ill post some pics tomorrow.

mk

marlinspike

The only thing I have to offer in all this is from looking at your spark plugs it looks like some power is left on the table in that you can run a more advanced timing. However, I only say that with so much certainty since I'm not looing at a close up photo (and it's hard, and perhaps a little foolish, to try to read plugs that have something other than a few full throttle passes on them).

shmark

Keep it! Extra compression.

Fabio421

So what is the final word on having Greg Brown do an alien autopsy on this engine?

mark kibort

actually, the last new belt was aligned in a similar fashion. there wasnt much stretching, as i never had to tighten the belt over the past 3 years. (maybe a 1/4 turn just because one time the tension was about only 1/2 way in the kempf tool window and i usually keep it about 2/3s

Mk

Ill use the old belt and compare the marks

mark kibort

It would have to be some interest in this engine by Greg to invest the time to do it. Right now, its almost down to a bare short block. a bunch of pan bolts from now, we will have a glimpse in to the heart of the Holbert motor. Im not going to touch anything.

mk

mark kibort

Heads were dropped off today and will be ready tomorrow. (Ellsworth Engineering)
We took them apart and also checked them for leaking. all but 2 cylinders were 100%. could be due to dirt during the intake disassembly, so we are going to clean them up a bit.

They noticed that the exhaust gaskets are in the heads (aluminum rings) . are they usually changed out? I know we didnt do them 7 years ago when i added the headers. are new ones easy to put in. (i suppose you just tap them in and the installation of the headers compresses to make a seal.)

If all goes well, i should have the engine built up by this weekend for the following Friday installation. (With Bill's help of course )

Mk