Deck height measurements driving me crazy, Need advice Options

[stugray]

yeahmag,

I only see the large difference in side-to-side measurements on one cylinder.
The other three only vary by a couple of thousandths.

I just ordered (yesterday) a higher quality depth gauge with a wider base.
I dont even want to mess with 'the mess' until I get the new tool.

I also intend to measure "piston wiggle" at a few different crank positions. This would tell me if the crank is bent.

I have always intended to get nice pictures of your tool in action, but I haven't got good results so far (my fault or bad parts)

Stu

[yeahmag]

That stinks... Sounds like something is messed up.

[r_towle]

Have you tried a simple feeler gauge and a straight edge?

[stugray]

Have you tried a simple feeler gauge and a straight edge?

Yes and it showed a difference from side to side but was not as repeatable as what I am doing now. You can see with your eye that the gap is different.

I repeated the measurements with the cyl @ BDC and I still see a difference of ~.006 from side to side.
I will get the new gauge the end of this week. I will try it all over then. ( and get pics)

Stu

[VaccaRabite]

Please put up some pictures of what you are doing.

Zach

[bobhasissues]

I have Jakes full race cam package.

You have mentioned this cam in several of your threads. Just curious, what is Jake's "full race cam package"? He refers to his cams by number, 9550, 9530, etc..Never heard of his "full race cam".

[stugray]

Bob - I would post a link to Jakes Type-IV store to show you but the site has been down for months.

I have Jake's "Full race Cam". It is the most aggressive cam he has, but I am not sure of the model number. I'll look for the cam card.
When you buy a cam from Jake, you can also buy the "full package" which includes pushrods, rocker shaft parts, and lifters.

Stu

[VaccaRabite]

Bob - I would post a link to Jakes Type-IV store to show you but the site has been down for months.

I have Jake's "Full race Cam". It is the most aggressive cam he has, but I am not sure of the model number. I'll look for the cam card.
When you buy a cam from Jake, you can also buy the "full package" which includes pushrods, rocker shaft parts, and lifters.

Stu

Unless he has changed things up again you can no longer buy just a cam from his shop. You have to get the full package.

Though last I heard he was discontinuing his cam kit program completely.

You can get the valve train upgrades (minus the cam, lifters and cam gear) from European Motor Works, and they are 100% worth it.

Zach

[stugray]

The cam is a: "Super 9700 Cam Kit", included a Type-IV store part # 9700 and all the other goodies.

I get a new depth gauge on monday.
Measuring with yeahmag's plate was more consistent but still shows a ??
I'll get pics as i do it with the right tools.
If i still see a problem, I will move a rod from 4 to 3 and remeasure.

Stu

[stugray]

Ok, got the new tools to do this right, and the results are the same:

Here is a picture of the two "rails" that hold down the cylinders (this is yeahmag's tool with AL spacers replaced with steel pipe).

(IMG:http://www.914world.com/bbs2/uploads_offsite/i366.photobucket.com-10819-1350969386.1.jpg)

Here is a pic of the flat plate that allows you to measure the edge of the cylinder, the edge of the piston (both sides and center)

(IMG:http://www.914world.com/bbs2/uploads_offsite/i366.photobucket.com-10819-1350969386.2.jpg)

Here is a pic of zeroing the depth gauge on the cylinder edge

(IMG:http://www.914world.com/bbs2/uploads_offsite/i366.photobucket.com-10819-1350969387.3.jpg)

Pic of one side piston:

(IMG:http://www.914world.com/bbs2/uploads_offsite/i366.photobucket.com-10819-1350969387.4.jpg)

And the other side of the piston:

(IMG:http://www.914world.com/bbs2/uploads_offsite/i366.photobucket.com-10819-1350969387.5.jpg)

I then flip the AL plate and repeat.
The measurements are dead on repeatable.

One side of that piston measures 0.022 and the other side 0.030.
The other cylinder measures 0.031, & 0.032 which I guess is more normal.

Stu

[rick 918-S]

What happens of you swap cylinders? I would investigate further. If you say the registers are flat. You need to find out if the cylinder issue repetes with a different cylinder in the same hole in the block. I'd start with the cylinders, then check the pistons before moving the rods around. Possibly a machining issue with the wrist pin height. If you start moving rods and pistons as a combo you may miss the issue entirely. I would take it in steps.
Same thing when tuning an engine. You don't want to change several things when running down a miss or idle issue. You more than likely want to work one item at a time until you know what was causing the issue.

[yeahmag]

Flip the plate end for end so the overhang "tang and slot" is over both cylinders. Use the slot to measure any height difference between the two cylinders.

)( <---- Measure both of them on the edges without moving the plate.

This is an idiot check for cylinder length and spigot issues. Let us know what you find.

[Valy]

What is your deck height right now? You should have about 1mm between the cylinder edge and piston.
It looks to me from the picture that the piston is hitting the rails from your measuring adapter. It might be just the picture but...

[jmalone]

Have you measured from the top of the problem piston to the top of the wrist pin bore on each side of the problem piston. Also you can measure the cylynder on each side from the bottom where it seats on the register to the top sealing surface where it seats in the head parallel to the wirst pin . Those measurements should be easy to do and at least you will learn if you have an out of spec cylinder or a piston with a mis-aligned wrist pin bore.

[stugray]

I will do the suggestions above, but for now I repeated all of the measurements with the new depth gauge. (again these measurements are all with no shims under the cylinders)

Cyl #1: Average deck height = 35.0 , "tip" of piston front-to-back = 0.0
Cyl #2: Average deck height = 32.75, "tip" of piston front-to-back = 0.5
Cyl #3: Average deck height = 30.75, "tip" of piston front-to-back = 1.5
Cyl #4: Average deck height = 25.5 , "tip" of piston front-to-back = 8.0

I also measured the "tip" of each piston while at BDC as well as TDC and they were all the same BDC=TDC, so I think that rules out a bent crank

So it appears that there is something wrong with cyl #4. My next experiment will be to just flip rod #4 upside down and repeat the measurements. That should tell me if my #1 theory is correct: that I have a bent rod or an improperly installed wrist pin bushing.

Stu

[JoeSharp]

Pull the crank and lay it on the bench with all the rod ends up and try to push a wrist pen throu all the small the small ends from one to the next. If the rods or the crank is bent it will show. It seems to me my father showed me that some rod from the T-1 tranny fit throu them and showed they were straight.

[stugray]

Joe,

Thanks! but I was hoping to do as many steps as possible without splitting the case again.
I thought about a similar step that I should have done before using the rods.

You could align and clamp all four rods into a vise from the crank end.
Then you should be able to get a wrist pin to slide through all four rods with a minimum of wiggling things a bit ;-) Didnt do that, but maybe next time. This would tell you if all wrist pin bushings are co-linear.

However, does anyone see a problem with my huge range of deck heights?

Cyl #1: = 35.0
Cyl #2: = 32.75

Cyl #3: = 30.75
Cyl #4: = 25.5

I do not see how I can buy shims to make all of those equal while keeping the deck on each head even for mating to the heads.

Stu

[wndsrfr]

Joe,

Thanks! but I was hoping to do as many steps as possible without splitting the case again.
I thought about a similar step that I should have done before using the rods.

You could align and clamp all four rods into a vise from the crank end.
Then you should be able to get a wrist pin to slide through all four rods with a minimum of wiggling things a bit ;-) Didnt do that, but maybe next time. This would tell you if all wrist pin bushings are co-linear.

However, does anyone see a problem with my huge range of deck heights?

Cyl #1: = 35.0
Cyl #2: = 32.75

Cyl #3: = 30.75
Cyl #4: = 25.5


I do not see how I can buy shims to make all of those equal while keeping the deck on each head even for mating to the heads.

Stu

Hmmm......#'s 1&3 are high relative to #'s 2&4.....seems like possibly your crank is not centered relative to the registers beneath the cylinders. Is it possible that your engine is composed of two case halves that don't match up? Like if it was put together from two different engines?? Just trying to think out of the box.....

[stugray]

Not sure what this means.

I flipped the #4 Rod and the side to side measurement was nearly Zero (25 & 26.5) but the average was still WAY off of the others.
So the "tip" went away but the average was still messed up.
I then flipped it again and the measurements are the same as before.

WTF!?

I am going to have to think through this one some more....

I have not set my endplay yet, but that should not matter yet...

[yeahmag]

Did you measure the cylinder height differences with the tool yet?