It's bored!!!

Bought my pistons ....ended up with a new set of forged JE 502 pistons for $150. :yes:
 
Bigtim44,

Damn. Good deal, even if they use the pricey metric rings. They are JE700s? Let us know what you find for ring options. Are you going to whack them flat? I've been meaning to see if the domes will clear into the 120cc head's chamber, and if the valves will clear with domes intact.
Dave

link=topic=347.msg4952#msg4952 date=1104179057]
Bought my pistons ....ended up with a new set of forged JE 502 pistons for $150. :yes:
 
I decided to go with the 76cc heads....On the pistons(which havn't arrived yet)I don't know how tall the dome is(don't have specs) ...the top of the dome might be somewhere near 0 deck....if it is I'll leave the dome on and cut valve reliefs.Can I do it this way?? so I don't need to cut the block down? :listen:
 
Tim,

The dome is above the pistons deck. IIRC, it's 4cc, and the dish is 3cc, for a final -1cc discplacement.
I'm pretty certain that the dome will have to come off to use 76cc heads. IIRC, the C.H. is 1.645" or so. Assuming you're using 7" olds rods, the deck of piston will probably be .010" or so below deck on an uncut block. Even cut flat, you'll have to be carefull with piston to valve on the 76cc. I'd choose a profile with a wide LSA, which should make TDC lift less.

Btw - I've wondered about re-machining the 1.5mm/2.0mm/4.0mm grooves to take either
1/16"-5/64"/3/16" or 5/64"-5/64"-3/16" rings. That's assuming there are 5/64" rings available for the odd-ish 4.446" bore size.
Dave





Bigtim44 said:
I decided to go with the 76cc heads....On the pistons(which havn't arrived yet)I don't know how tall the dome is(don't have specs) ...the top of the dome might be somewhere near 0 deck....if it is I'll leave the dome on and cut valve reliefs.Can I do it this way?? so I don't need to cut the block down? :listen:
Click to expand...
 
I am thinking that the 502s have a metric frigging set of rings too, may check on what probe cut lands to fit. I know that hastings offers std type rings(american) but I don't know about metric in oversize.
 
Richard,

Everyone except GM uses 1/16" 1/16". The GM metric 1.5mm top groove can be cut to 1/16", but not the 2nd, as it's 2mm, which is wider than 1/16". Need to see if there are 5/64" in that bore size.
Dave


POTTER said:
I am thinking that the 502s have a metric frigging set of rings too, may check on what probe cut lands to fit. I know that hastings offers std type rings(american) but I don't know about metric in oversize.
Click to expand...
 
Tim,

You know, with an 80cc chamber, a .045" quench and a flat top, you'll be at 13-1 compression.

Have you looked into the composite gaskets?
Dave
 
I havn't researched the gasket thing in depth...although I think I'm leaning towards copper and o'rings.
 
The gaskets are done by someone else and the quality is very good.
I just buy the gaskets less O-rings and they put in whatever size fore rings that I need.

  Probe uses standard rings in all the pistons that ive seen or purchased from them.
I would lean toward the 1/16-1/16-3/16 as opposed to the thicker rings.

JE has the rings for the pistons they made and most of JE rings are made by either Grant or Hastings.
 
Hi John,

You can do a set of composites for 4.447"?

Tim,

As far as rings, the metric set is readily available, but pricey, as afaik, they come only in premium
mat'l. Plasma moly, possibly. That's probably the best bet, as I checked today, and besides the
metric set, there is no shelf set with anything other than 1/16" on 1st and 2nd. You could get
a custom set thrown together with 5/64" 2nd or 1st and 2nd, but I bet it'd cost more than the
shelf metric set. Plus the work/cost of machining the grooves to fit 'em. Sometimes being a cheap
sob costs more -LOL.
Dave


TORQUE INC said:
The gaskets are done by someone else and the quality is very good.
I just buy the gaskets less O-rings and they put in whatever size fore rings that I need.

  Probe uses standard rings in all the pistons that ive seen or purchased from them.
I would lean toward the 1/16-1/16-3/16 as opposed to the thicker rings.

JE has the rings for the pistons they made and most of JE rings are made by either Grant or Hastings.
Click to expand...
 
Hey BIGTIM44, FWIW I'm really regretting not using copper and O-ringing, I've got Flash's Fel-Pro's and now I'm scared to spray this thing. If TI's modified Corteco's won't handle alot of cylinder pressure; I'd go copper. Piece of mind is worth alot. JW- do you have the new Corteco's in hand and ready to ship, or are they custom per order? Thanks, Cooke.
 
Havent really put the cortecos to the extreme test yet
They are per order in just about any bore size.
There is another gasket option in copper that I am looking into and will test before I sell em and Ill let everyone know.
It will require O-ringing but no sealant.
 
Thanks guys for the input on the head gasket thing,I don't mind paying for the metric rings....the guy that does my machining can get me parts for wholesale price although I don't even know what retail is for them!!?? :eyebrow:
I should be able to get some pics of the block loaded up as I got a new compoota,my old computer finally spat the dummy out and left me high 'n' dry for about a week+.
 
Copper copper copper copper. You have a very nice project going, if you are going to get the most out it as far as compression (and you should) it'll never be street driven-no? O-ring that thing and forget it. On a 10 or 11 to 1 you can easily get by with composition. 12-1 +- copper . O ringing is simple to a competent shop. Should only be $200 or less. Worth every penny.
 
Hey BT44,

How's this project doin'?

Looking forward to hearing an update.

~JM~
 
Bigtim44,


> I don't mind paying for the metric rings....the guy that does my machining can get me parts for wholesale price although I don't even know what retail is for them!!?? :eyebrow:

The metric rings are only for the GM only JE700, afaik. R10575-5, [+.005", 2mm/1.5mm/4mm]
Sealed power. $183 from Northernautoparts.com

The Probe, etc should use 1/16": 2M5537 Powerflex. $152 from same. Plasma top for $185, iirc.

Fyi - northern did have an e-bay auction with those 1/16" rings a few times. Search in pistons for 502. Ther'll pop up.
Dave
 
Currently: having the pistons dome cut off ,weight matched and the rods fitted to the pistons,decided to have the block cut for o-rings and copper,The guy that does my machine work wants to do a rotating mass mock up i,e, crank 1 rod and 1 piston to figure out the deck cut and fly cuts for valves,pretty slow progress I guess...the old time and money thing getting in the way.I'm still in the dark with camshaft choice....but I'll have to make my mind up soon!!
 
Hey there BT44,

  Anything new happening yet? :nosy: :listen:

~JM~
 
With the pistons you are using without getting the dome takin off, what would the compression be around?  Im looking to get around 9.1 out of mine.
 
He is boring the engine .146 over
quite a bit different than what I think your looking to do
 
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