You may recall a recent post I put up about a cam installation issue, this has been resolved and I went on to build the rotating assembly today. I thought as I was building that the pistons seemed pretty far in but at that point had no idea what the spec should be, as I didn't check the deck height when I dissassembled the engine, so I started searching the moment I got home and after finding out that it should be in the area of .140, I decided to ride back to my shop and measure. I dont have any specializd tools for this but I suspect a dial caliper that has the shaft out the back should work and I get .420, yeah the pistons are nearly half an inch in the hole.

I took the block, head, crank, rods and pistons to a local shop that has a pretty good rep, They got me one new rod as my #6 was gone but said the turned MY crank. They also supplied and pressed new pistons, sealed power .030 244np.

I wonder if there is a crank or rod discrepancy in the engine, the block number is 2806830-3 which seems to decode correctly as a 1969 225 the
head does also. I haven't been able to find any markings on the crank except a large P and a large 4 the rods look pretty consistant with the numbers 2205554 on one side of all of them (I think) and various numbers on the other ex. 16025, 16016, 16029. How can I determine the origin of this crank? At what points can the stroke be measured? Please help......Sorry for the lengthy post.

What Gives, wrong crank? rods? pistons?

_________________
225 .030
.020 off the block .100 from head
Comp 264
904 Tranny
New Ebre-ting

http://s78.photobucket.com/albums/j103/edrod01/

The only thing I can figure is that somebody installed 198 pistons on a 225 crank. That is about the difference in deck height between your 2 numbers.

Mike
www.PowreHaus.com

_________________
Recognized by US Federal Courts as a Fuel Economy Expert!

Well all the info I can find suggests that the pistons are shared 170-225 but the rods and cranks are all different any casting #'s to look for on either. The pistons are new.

_________________
225 .030
.020 off the block .100 from head
Comp 264
904 Tranny
New Ebre-ting

http://s78.photobucket.com/albums/j103/edrod01/

As I recall (and it's been awhile since I looked this up), the 170 and 225 share the same pistons and rods, the 198 and 225 share the same block, the 198 has it's own pistons. Or, was it the 170 & 225 share the same rods and all 3 use the same pistons? I'll have to check my MP Manual tomarrow.

Mike

_________________
Recognized by US Federal Courts as a Fuel Economy Expert!

All Slants use the same pistons, each one (170, 198, 225) has its own distinct crank and rods, the 198 and 225 share blocks and the 170 has its own.

Lou

_________________
Home of Slant6-powered fun machines since 1988

O.K. How can I determine What crank and rods I have. Are there any casting numbers available?

_________________
225 .030
.020 off the block .100 from head
Comp 264
904 Tranny
New Ebre-ting

http://s78.photobucket.com/albums/j103/edrod01/

Somebody gave you a 198 crank, does it have a big rear hub?

Measure the piston position at TDC, you have done this and got the -.420 reading. Rotate to BDC (Bottom Dead Center) and measure again, my bet is you will get 4.060. If you do, you have a 198 crank combined with 225 con rods.

Another tip-off, .420 - .305 = .115 Did you mill appx .025 off the block deck? ( 225 rods are 6.700 c to c, 198 rods are 7.005)
DD

Yeah they took .020 off the deck. 198 crank , huh? That is exactly the conclusion that I came up with last night.

What is the likely hood that this is the crank I took out of the engine, the car ran for a second when I got it but had a spun rod bearing. Would an engine even start with this kind of deck height?

The block and heads both have the cars vin stamped, and I have no reson to think the engine has been rebuilt. What will the flange size be on a 198 what size on a 225? Would the flex plates interchange?

_________________
225 .030
.020 off the block .100 from head
Comp 264
904 Tranny
New Ebre-ting

http://s78.photobucket.com/albums/j103/edrod01/

Spoke to the machine shop this morning, they did infact use a core that they had instead of turning mine.

He said they measured them both and the stroke was the same, but asked me to bring back the one they provided to re-check.

Can't wait for this apology.

_________________
225 .030
.020 off the block .100 from head
Comp 264
904 Tranny
New Ebre-ting

http://s78.photobucket.com/albums/j103/edrod01/