Mocked up the rotating assembly, spins freely WOOOHOOO!!! only it don't have the same deck height! The machinist assured me it was square, and that he only removed about .007. Now I don't have a dial indicator with the fancy bridge for the deck like a machine shop. So this is being done with a piece of bar stock (nice and square) and feeler gauges. Being really diligent to index the crank and checking across the board 1-4 & 5-8.

I'm getting .026" for 1-4 and .033 for 5-8 (.033 - .026 = .007) wow who'da thunk it? So from what I'm seeing my guess is the deck ain't square eh ?

Question: how bad is this? Worth having the .007 taken off 5-8 bank ?

Seems to me the CR is going to be off just as much as the quench resulting in basically a waste of my time if assembled as is.

 

Sounds almost like the machinist forgot to mill the one side since it is off the same amount as he said he milled it.

 

Now aint that sumpthin!!!

At least your measurements are consistent from hole to hole within the same bank. I've read it's pretty common to have one end of a bank higher than the other.

 

I'd have him do it right. What does your reciept say? I agree with you that your compression would be different from bank to bank. Whether you'd notice it or not, I don't know, but from an engine builder I know, he considers the squareness of the block to be important for many reasons.

 

Well Bobby the deck being squared is one thing and decked is another... You better have the shop check it again.... Your square come from the centerline of the crank saddles to the deck.. and the Deck comes from your centerline to the top of the pistons at TDC to the deck to be even across the board, so if your Head Chamber CC's are all the same your CR will be all the same within tolerance's on all 8 cylinders.. and i personally wouldnt go under a .035" quench and over a .045"... helps with detonation too and quick burn...

 

Well let me get back in here ....I wrote my last bit in a rush.... Bobby .007" out on a street motor thats not gonna be a killer build isnt that much... I have seen a hell of alot worse on street motors...and lose even more with the head chambers not CC'ed.... So If your worst cylinder is .007" off that could make as much as 1cc in chamber volume.. which for a street motor isnt *****.....

Didnt meen to worry you about the last post.....I just had people talking to me at the same time I was trying to think and type..LOL...

RJ

 

I removed the feeler gauges from the housing and laid them atop the piston flat and ran the tests again. The 1-4 piston are .028 and the 5-8 pistons are .032/.033 so maybe it's better than it looked ? I guess we could go with the steel shims and have .49 on the 5-8 bank, with .45 on the 1-4 bank ? Still seems kinda high based on Dino's input on the post I had bout the piston search. Guess I'll get the heads CC'd so they can be torn back down and the final polish work done on the ports.

 

Oh, absolutely... My machinist went the extra yard, put the pistons/rods/crank into the block (without the rings) while he was checking all the bearing clearances, came up with measurements for what to take off the deck, and did just that. I watched/helped him do it.

And it came up perfect after it was all reassembled. Too bad I froze the damn block and cracked it behind the flywheel - he got that thing absolutely freakin' perfect...

15 years later, I still feel ashamed for screwing up his work...

 

Well Bobby like I had said before .006" on the head equals about 1cc of chamber size.. So at the factory if the pistons very in the hole .003" to .007" and your deck isnt flat say your .007" out... and then the chambers are 72cc to 74cc's add em all together and see where your at?? LOL...

I mean you paid to have it done Decked that is...and I wouldnt take it "because" I paid for the job to be done.. And I would have ta take it back for my own piece of mind..Thats just me... I try and get WTF I paid for.... But "I" dont think your gonna feel it on the ol "Butt-O-Meter" But I would want it done right being how I paid him for it!! JMO...

Obvisously he just took a clean-up cut on the deck...and didnt Mock the rotating assy and look to see where he needed to go for the square and deck from the top of the pistons... But your also going to run across deffrence's in spec's if your rods werent checked for stretch and are all the same size...CH on the pistons from wrist pin centerline to the top of the piston...

He needs to add all these things together and take the mean.... and deck it where you want it at... But that shouldnt be done until your done with CCing your heads so you know where thats going to stand at... So when CCing your heads..the largest Volume is say 74cc's and you clean and polish them all out to 74cc's...then you have a standard for you deck to go from for adjustment for your compression ratio !!

And dont worry about your Main bearing specs as long as they fall within tolerances of the MFG.....

And of course always remember what selection of head gaskets you have for adjustment to your Final CR also....

RJ

 

I'll be CC'ing the heads over the weekend hopefully and possibly get a decent dial indicator setup rigged so I can get a legit look at the numbers. Then we'll see if it's worth asking John how much to skim the top. I'd like it to be right and he seems to be the kind of guy who will make it happen if I ask. Kinda want to get the rest of the thing gone over so if I head back down I can knock out anything else in one pass. So far things are looking pretty good though.

I mean when you get down to it, the idea of having a zero deck doesn't come without having to do some work on the intake IIRC and for a DD that is mostly a fun/work truck at the moment I cant see going to all that and really don't think it's warranted for the general purpose the engine will serve. I'm sure if your a machinist with all the tools handy this is all just putty in the hand as you can do the stuff for ¢'s on the dollar and don't care what snags you run into along the way. When your wondering where the money is going to come from to get to work next week then your mind set isn't getting that extra .008hp out of your beat up old slick.

 

Well Bobby I have to agree , It being a DD and not a Hi-Po build....its really not that criticle<-sp? .... as long as every thing when it adds up isnt way out... And I really dont think you can get any further out than a stock Any Maunufacturer build.. I just get picky and really dont mean too..when it comes to tolerances...On a basically stock buils...

And as for a dial indictor and a mag base thats gonna give you how deep the pistond are in the hole when mocked up.... Do you know how to CC your heads...I'am sure you have already read about it... But maybe you havent is the reason I ask?

RJ

 

What I've read and seems the easy way is to use a piece of plexi with holes drilled in it and a cooking syringe, lighty grease the surface of the head and place the plexi in place then fill the holes until the water reaches the fill hole. Then read the CC's left in the syringe and do the math. sounds easy enough LOL like anything else I'm sure it will be eventful ahaha

I figure with the extra mile I have gone on some of the stuff this engine is bound to exceed a stock build up and and surely have an extended life in comparison. Sure hoping so anyhow.

 

Well pretty damn close to what I do..... I also use a piece of plexi about a 1/2" bigger than the chamber....and run a coat of Vasilene around the chamber... and 2 holes one for feeding and one for venting.. Now I have an 18" by 32" piece of granite sitting on a table with adjustable legs to get it flat... and use a dail indicator on the head suface to get it flat also... I use a 100cc Lab flask..there's another name for it.. and use mineral oil in it... There may be a more trick wat to do this now...But its just the way I was taught...

And plus instead of having to keep filling up syringe.. its just done all in one slow flow... But like you said its petty much straight up.... LOL

RJ