427 engine..
 

Came across an engine in my travels this weekend. 512 block H309..August 30, 1969..it has 842 aluminum heads and a vintage Edelbrock slanted manifold. Don't know anything yet about the bottom end..deck numbers appeared to be gone from a prior rebuild..is this too late to be a 69 L89 motor...could you buy this setup over the counter...thought it might be of interest to someone here..... any thoughts?

wilma

Re: 427 engine..
 

Tom I'm restoring a 69 L-89 corvette and it's body build is 8-28-69. I also have seen later L-89 vette's. It also could be a L-88. 074's came into production in the 21000 serial # range. Which was earlier than this but it could have been a left over.
Rich.
it may be worth poping a head off to look for High dome pistons...or pulling off the pan to see some dimpled rods https://www.yenko.net/ubbthreads/imag...ns/naughty.gif

Re: 427 engine..
 

I will try to get my friend to remove the pan so I can see about the crank and rods. This would be an awesome setup in a street machine... The heads are real nice: no welds or broken stud mounts....should have some more info tomorrow.

wilma

Re: 427 engine..
 

"could be a L-88."....Cant be an L88 w 842s that late in production. Open chamber pistons wont mate to 842 heads and closed chambered L88s were long gone by Aug 69. The "leftover" head theory wouldnt apply as the matching closed chambered pistons would have to have been used in conjunction with the 842s also. The pistons cant be swapped out on those 2 aluminum head castings... Both motors used dimple rods so looking for them when dropping the pan wont tell you except the L88 had floating pin 7/16 and the L89s had 3/8 pressed pins dot rods . #7115 crank used in all production L88s,#6223 sometimes used but mostly the #7115 cranks used in L89s.

Re: 427 engine..
 

[ QUOTE ]
"could be a L-88."....Cant be an L88 w 842s that late in production. Open chamber pistons wont mate to 842 heads and closed chambered L88s were long gone by Aug 69. The "leftover" head theory wouldnt apply as the matching closed chambered pistons would have to have been used in conjunction with the 842s also. The pistons cant be swapped out on those 2 aluminum head castings... Both motors used dimple rods so looking for them when dropping the pan wont tell you except the L88 had floating pin 7/16 and the L89s had 3/8 pressed pins dot rods . #7115 crank used in all production L88s,#6223 sometimes used but mostly the #7115 cranks used in L89s.






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The Knowledge https://www.yenko.net/ubbthreads/imag...ns/scholar.gif https://www.yenko.net/ubbthreads/imag...ns/scholar.gif on this site is beyond belief......... https://www.yenko.net/ubbthreads/imag...iggthumpup.gif

Ken https://www.yenko.net/ubbthreads/imag...mlins/flag.gif

Re: 427 engine..
 

[ QUOTE ]
"could be a L-88.".... #7115 crank used in all production L88s,#6223 sometimes used but mostly the #7115 cranks used in L89s.


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Kevin, please elaborate on this point for me. Are you
saying that 427 L/89's used '7115 cranks? Less the L-88
and ZL-1, I don't think any other production 427 engines
got the '7115. As only the '842 heads separate the L/89
from the L/71, L/72, L/78 - how or why would the '7115
crankshaft replace the '6223 in production? I expect there
could have been exceptions, but my research has indicated
that the '7115 was super-special ( L-88 & ZL-1 ). Please
correct me if I'm wrong. https://www.yenko.net/ubbthreads/imag...mlins/hmmm.gif

Steve

Re: 427 engine..
 

Hey Tom !

I'm still waiting for you to build that oval port 396 with
the L/78 camshaft. https://www.yenko.net/ubbthreads/imag...ns/naughty.gif And after what we learned last
week about using the rectangular port intake with the oval
port heads ( power up to 6500 RPM's ), I can't wait to see
someone try it. Odd thing is I have all the necessary
components ready ( L/34 - 402 long block, L/78 camshaft,
and the now infamous rectangular port intake ). I just
have no time to do it or a car to implant this into. https://www.yenko.net/ubbthreads/imag...mlins/hmmm.gif

Steve

Re: 427 engine..
 

I agree...it is on the list of things to do. Got 2 396 blocks in the garage and 4 sets of oval port heads..that should get it done. I have 6223 crank and a decent set of rods and lots of misc. stuff. I am out of 163's at the moment..used the last one on the project car. But they are avaialble.....it would be a cool motor to drop in Karen's 69 Camaro and put that little small block in the corner https://www.yenko.net/ubbthreads/imag...ns/naughty.gif still need to build a 4spd street Nova that I can beat on..this would be the engine for that effort!

Re: 427 engine..
 

I was told all 427s used the 7115 crank.


Jason

Re: 427 engine..
 

Hi Guys,
I have had two original 69 L89 Corvettes(one for almost 30 years)and both of them had the 6223 crankshafts. One is a January car that is a 4spd and a late Feb. car that was an automatic.Both cars are very original and unmolested. I also have a spare original L89 engine that is serialized for a car built 2 or 3 days before my Jan. 4spd. car and it also has a 6223 crank. To the best of my knowledge, the 7115 cranks were only used in the L88's and ZL1's.

Re: 427 engine..
 

My guess is that the 7115 cranks were probably used with the heavier open chamber 12.5:1 domed pistons for the L88 and ZL1 since the counterweights are slightly wider for balancing purposes. The 396 and 427 11:1 closed chamber pistons were lighter and worked with the narrower counterweighted 6223 crank.

Paul

Re: 427 engine..
 

I checked with someone i know who has taken alot of virgin motors apart and here is what i was told,it kind of falls in to what i had stated.Hope it helps ! 1967 435hps taken apart for the first time have had 7115 cranks with very few exceptions, 2 bolt main 427 motors usually had 6223 cranks,only corvette w 2 bolt mains ever used a 7115 . 427 COPO 427s mostly had 7115. Impala and passenger 427 hi perf used 6223 exclusively,this is from a pool of around 150 motors that were taken apart seemingly for the first time. As far as L88 and ZL1 ,only 3 L88 and 1 Zl1 were taken apart like this and all had 7115, Still have yet to see a 6223 crank even in a new crate motor from the late 70s as has been claimed,although certainly a possibility 8 nos assemblys from the 70s have had exclusively #7115 cranks " There you go !

Re: 427 engine..
 

Hi Kevin,

I don't want to bang heads with you here but I have not
heard of one COPO 427 with a factory '7115 crankshaft.
Several members here own them, perhaps they would care
to elaborate.

Additionally, I addressed this very issue last year on
the NCRS forum and walked away with the understanding that
the '6223 crankshaft was the common crankshaft in use at the
time. It existed in various forms: standard, cross-drilled
and cross-drilled/tufftrided in both 396 & 427 applications.

The comment about the '7115 being used in conjunction with
the 12.5:1 pistons seems quite plausible to me.

Re: 427 engine..
 

Kevin,

I did learn that evidently some of the '67 L/71's used the
'7115 crankshaft as you indicated. That appears to possibly
be a 1967 situation only - though.

Steve

Re: 427 engine..
 

Has anyone heard of using a tall block spacer to match up or transition an oval port manifold with rectangular heads? Hey Nuch, what was that about using a rectangular manifold with oval heads?

Re: 427 engine..
 

Michael,

Not sure about using an oval port intake with rectangular
port heads. Doesn't make much sense. The oval ports are
good up to about 6,500 and that is about where the rectangular
port heads are getting started. I would think that the intake
would reach the choke-off point just about when the heads
were ready to go-for-it.

From the number of posts here and on the NCRS forum, it's
evidently quite common to mount a rectangular port intake
up against oval port heads and get good HP up to about
6,500 RPM's. The bolt pattern is exactly the same so there
is no problem there. Just use the rectangular port intake
gaskets if you do this. I will try this myself one day.
It's got my curiousity peaked. https://www.yenko.net/ubbthreads/imag...ns/naughty.gif

Steve