67442nut

Dug out a '67 4-4-2 short block I've had buried at my shop for years.
Long term moisture exposure in an unheated area has taken it's toll on the cylinders.
It will more than likely need to be bored.
I know from past posts I've seen on the subject that availability of oversized pistons
for some Olds engines is limited.
Can someone tell me if oversized pistons are available for the"E" block 400's?

lemoldsnut

Check with Greg at Supercarsunlimited.com he lists them in .30 and .60 over.

http://www.supercarsunlimited.com/Pistons-i105.aspx

lunaboy

or bore it to std 350 flat top specs.

Fun71

Yep, the early 400 has a 4.000" standard bore so using a standard bore 350 piston gives ya 4.057" bore.

Years ago I bought a set of Sealed Power std. bore 350 flat top pistons that had a 12 or 14cc dish milled into the top of them for use in the 400E that a neighbor gave me.

steverw

Egge pistons are also available in overbore sizes. They are cast as originals, not forged, but if your not making a ***** to the wall HP motor their probably pretty good.... I hope

67442nut

Lem, Luna and Fun71, Thanks for the info and advice.
I've actually looked at that.
The 350 piston is 4.057" dia. which is .003" less than 4.060" needed.
I didn't know enough to know if that's within acceptable tolerance,
if the difference can be made up with rings or if
the boring can be precise enough to overbore the block .057" instead the.060".
Also didn't know how the wrist pin location compares between the 350 and 400 pistons.
You've answered those questions for me. Thanks again.
Jagness on the ROP site informs me that wrist pin locations are the same on the 350's and 400 "E"
which answered that question as well.


Went to Supercars site to see what's available.
Looks like a set of 4.030" or 4.060" 400 pistons cost about the same as the
4.057" 350 pistons.
If I have to buy new, I'll probably just buy the .030" 400 pistons
to keep from cutting the cylinders any more than necessary and keep the rebore a more typical round number.
I'll try to find some good used 350 flat tops first.

steverw

Ed i just looked at those pistons, id be willin to bet they are Egge pistons. I have been told Egge is the only one that makes them but then i dont know all. You might call Egge and see if their price is the same as SCU. I put the Egge pistons in my E block so I hope their good. Hopefully there as good as the factory cast piston. I do kind of wish I had gone with the 350 forged pistons.

2blu442

I haven't tried this myself yet, but my favorite mechanic says there's a Dodge 360 piston that will work if you open up the wrist pin hole.

John

hurst68olds

A standard Mopar 360 is 4.00", there was discussion here on CO of a combination to use 360 pistons in a '68-'69 400 (standard G block 400 is 3.87") ending up at 427 cu. in.. Can a similar combo be used in the '66-'67 400? (standard E block 400 is 4.00")


cost and available choices are the variables
some forged Mopar 360 pistons cost about the same as cast Olds 400 pistons

Oldsmaniac

Ed I think you would be better off getting the pistons from Egge as well. Kanter sells Egge with a markup and probably so does Supercars as already mentioned.

Run to Rund

If you get a set of Sealed Power type W31 forged pistons, run .0045" clearance at the bottom of the skirt. They will scuff with less clearance. I don't trust cast pistons, if any type of performance use is envisioned.

cutlassefi

Don't use an Egge or Kantor if at all possible. Imo they're not worth what you pay for them.
Use a forged anything if possible.

67442nut

Thanks, guys, for all the good input.
Since I have multiple projects I'm trying to do
with limited resources (never said I was smart )
I'm trying to optimize what I spend.
Looks like the best route for my purposes is these:
http://www.jegs.com/i/Sealed-Power/8...oductId=755706

67442nut

Haven't bought pistons yet.
Was about to order the 350 pistons when
I remembered a set of .060 over Jahn's forged aluminum pistons
I bought in 1970 with the first paycheck from my first real job.
They've been on the shelf in the original box ever since.
I know they're not state-of-the-art technology, but ,
that's not an issue for me as they'd be used in a pretty day, cruise in car.
I can save the cost of new pistons by using these.
Problem is they're 13:1 CR (I know that will vary with the build.).
I don't need that kind of CR.
My question is can the CR be lowered to around 11:1
by using a thicker head gasket or using heads with
a larger combustion chamber volume?
Would using a thicker head gasket cause a problem with push rod length?
I checked the dome thickness some time back
to see if the piston dome could be machined down, but,
there's not a lot of "meat" there.
Any suggestions or is using these pistons just not gonna work?

Run to Rund

Are the pistons domed? If not, you will get around 11:1 with a .028" head gasket like Corteco (Fel Pro are .040" thick) and zero deck. Without decking the block, the pistons probably will be .025" down the hole. It would be best to check cc's and calculate the actual compression.

67442nut

Yep.
The dome is basically a flat dome about 1/8" thick all over the top of the piston.
8ac2e362-81ff-4478-8ce5-8b35592ea8d4.jpg
c79da411-f20e-4275-a8b6-32e3256b431f.jpg
a887a2bd-4ffe-4992-9366-52fdb1bf3f82.jpg

cutlassefi

Look to see if that can be milled off. They're definitely an older design.

67442nut

Thinnest part of the piston top is approx. .200" thick.
Dome is approx. .120" thick.
If It's milled down to a flat top, is a .080" thick top safe?
What is the thickness of a current forged aluminum flat top piston?
What's the difference between 1970 metallurgy and 2016 metallurgy
of a forged aluminum piston?
If this piston can be made useable, any drawbacks to the 1970 technology?

cutlassefi

Well they haven't done full skirt designs like that in awhile for one thing.
Are you sure the total deck thickness is only .200? That's a bit thin, even for that style of piston.

Fun71

Looking in the piston from the bottom, is the domed portion recessed? If not, wouldn't the .120" dome be in addition to the piston top's .200" thickness for .320" thick? If so, milling would leave the .200" thick top of the piston.

I am basing this on the set of L2320F flat top pistons that I have with a 12-14cc dish milled into the top. There is still a lot of material below the dish.

67442nut

The .200" includes the dome thickness.
It is the total thickness of the piston top.
I considered partially removing the dome
if that would get me to a useable CR.
Talked to the local machine shop today.
They're talking $150.-$200. to mill the pistons.
For that much cost, I'll probably go ahead with the original plan
of buying the Speed Pro 350 pistons.

Fun71

Yeah, for that price new pistons are a good choice.

Bernhard

A modern piston with a modern ring pack will be well worth the investment.