Deck height numbers

[Dirtweazle]

Looking at what people are getting for deck height numbers..

I am building a low buck from Dino's recipe. My issue is this:
Sent block to get redone, bore 30 over and .030 taken off the deck.. Got the silvolite dished pistons (30cc).. Short rods and stroker crank.. The head was rebuilt and .005 was taken off to make flat. I checked the volume on the head and they where around 56cc.After piston assembly I started checking deck height and im getting .039.. Running the calculator my compression is way too low even with the .043 HG.. I dont think my block builder took the .030 as was requested and I was billed for. I took the head into another shop that (under the machinists recommendation take another .020 off the head.) I did this and was only charged $40 and a one day turn around.. The head vol now check out to 51cc. I know its still a little low on CR but I need this thing running this weekend.. I may switch to the .043 HG to help lower CR a few more. This may get me right on.

Any one experience this?

-Troy

[seanyb505]

30cc is a lot to take from the pistons. When I found out mine were 30cc I took more drastic measures to get the CR to a desirable level. I had the block decked .045 and the head decked .015. The .045 Head gasket will raise your CR if your using a stock .051 piece. You might want to go to the shop that didnt deck the block and talk to them about it. Bring measurements and such cause they wont believe you unless they are honest.

[Diamond-x]

dirtweazle,

How low is your calculated CR? I don't think .039 is stock deck height. I calculate mine at .054 prior to machining. This is with a 258 crank and rods and 677cp pistons. I'm not sure what your silvolite impression thickness is. I'm shooting for .040 deck height, measured with crank rods and pistons in place and THEN machined.
It's been a while since you posted, how did it work out?

Diamond-X

[Diamond-x]

I meant compression thickness

[Dirtweazle]

It Runs!!!! After all day saturday banging out oilpan to fit Melling pump, Searching garage for random bolts to fit pan. Load up all tools, picker, parts, Monsters. We finaly went out tothe place I have the Heep at.. From 9:00am on we busted our humps.. Thanks to my buddy and his determination to hear it run, it was start time by 9:30PM. By the 4 th try it turned over and caugt.. Really rough for the first few untill we twidled the (have a 2k) not the distributor looking thing around a few. Kept it at mid 2k rpm's for a bit, computer caught up and we checked over everything. No leaks, oil, water, gas.. things where looking good till.. Once it got warm the radiator told us I dont have a cap on me! I stalled the rough idle and it puked its coolant guts all over my nicly polished motor. Looked everywhere but I could not find the cap. Oh well job well done tonight.. It RAN!!!

Sunday got cap and a few other nickle and dime crap that you always need. Got her caped and she is still running a bit rough but does idle, warms up quick, oil pressure is 80( max of the guage). Not sure if this is something to be concerned about ? Totaly different sound than the 4.0. Exhaust does have something to do with it but its the engine that just sounds different, meaner. It really growls. May be and exhaust leak.... No banging, metal noises, fire and such.. No screeching and sudden engine stops..Just a bit of valve rocker noise. some detonation but thats from the old gas in the tank. Same as I heard with the 4.0. I need to get the timing set properly. Drove it around the neighborhood. Nothing much but im estatic she moves under her own power.. I also installed 5" of lift so steering was waaaaayyyyy out.. That slowed me down more than anything else. She is jumpy at that first throttle touch. Really quick.

From my initial feelings im nervous. A lot of time , money, efort, my DD, my wifes sanity are riding on this and im just nervous. Baby steps...

My CR was at around 8.50 or so by calcing the numbers.. (Cant find my notes at the moment) with .051 HG. .The .043 would have got me to 8.7 something (still under stock) but I wanted 9.0. I already had the .051 and the .043 was $34 with tax. Talkig with the manager and what I was up to. He refused to sell me the hg and dialed up his machinist and had me talk to him.. $45 and I get what i want and a one day turnaround. He took off .020 from the head (.005 was taken off before at head rebuild)and I vol the chambers to around 50 - 51 cc now. This gets me above stock but not to the magic 9 but im fine.

BTW Sun evening I droped off all my tools and picker back at the garage and found the rad cap, sitting with all the oil pan bolts in a baggy LABLED oil pan

[Geo.]

Are you running the stock push rods?

[Dirtweazle]

Yes. with .030 shims under the rocker bosses..