Plastic Fantastic tew

[SuperBuickGuy]

well, news is still news.

I figured, based upon measuring, that I'd need to do a split 20/30 under bearing, I was right....

at least the deck height is zero... too bad,

and I put some color on it


too bad - did I say too bad, yep. with 119cc heads instead of the 110 cc that I got with the motor the compression ratio is a disappointing 8.97:1. I can help it with .027 head gaskets (which are .012 thinner then the FelPro) and bring it to 9.17:1 but I think I'm going to either have to deck the block and/or deck the heads as well to get the 10:1 that I desire.... not a huge deal, but I'm not building a swill-gas-motor so steps will be taken.

[Deaf Bob]

Running derbys.. Revs are close to full song, quick throttle downs to shift. Larger pans get poked.. Block and heads got smoothed to aid drainback.. We run regular oil pumps as not to drain the pan.. Once the nose rises, all oil is in the sump anyways..

Smoothing the lifter galley and deflash the drainback holes, slightly countersink helps too. Same in the heads. There is a noticeable difference before adding the pan and pouring a cup of oil in a drain hole.. Smoothed ones really do make a difference..

[fatguyzinc]

well, news is still news.

I figured, based upon measuring, that I'd need to do a split 20/30 under bearing, I was right....

at least the deck height is zero... too bad,

and I put some color on it


too bad - did I say too bad, yep. with 119cc heads instead of the 110 cc that I got with the motor the compression ratio is a disappointing 8.97:1. I can help it with .027 head gaskets (which are .012 thinner then the FelPro) and bring it to 9.17:1 but I think I'm going to either have to deck the block and/or deck the heads as well to get the 10:1 that I desire.... not a huge deal, but I'm not building a swill-gas-motor so steps will be taken.

cant find .015 steel shim head gaskets? i spray mine with aluminum
colored paint first and put em in tacky, then torque in 3 steps with
NO sealer on the bolts, go have lunch or something, then on return i
pull each bolt 1 by 1 (in the correct order to torque) and then smear with
sealer then retorque in one step to whatever the max specs were.

mark the bolts before you pull (or count turns ) and be amazed and scared
at how much farther they go down on the retorque...

in 30+ years, on dozens and dozens of motors--my own as well as every
customers- i have never had a head gasket failure, on everything from a mild
15 second 283 SBC to a 555 that was built to run the 9.90 index but went 8.78 on
its first pass--so the guy just ran a throttle stop instead, worked perfect.

[SuperBuickGuy]

If I had a dollar for every time I heard the line "well, I've never seen that before" I'd be driving a new Corvette (actually, probably not, I'm not that smart).... the reason for that is twofold - first, often I'm that terrible guy who does something just to shut someone down who said "never" or two (the universe balance) it blows up in ways no one could have foreseen.

That said, I think I need the .0012 from the .0027 gasket, and another .0020 from shaving to get the compression ratio to reasonable.... .0015 will only get me .0022 rather the .0032. Every .0010 is a 1/2 point of compression. The other thing is I can get 4.310 gaskets in Cometic .0027. All the thinnest ones I've found are 4.500 or larger.

[Russell]

"20/30 under" does that mean 20 on the mains and 30 on the rods?

[SuperBuickGuy]

using a 20 on one half, a 30 on the other half

[fatguyzinc]

seems like a shame to have to redisassemble the heads or block
to deck...oh well, you gotta do what you gotta do. cant run that
cam you were looking at without enough compression or it will
be doggy, soggy, and boggy instead of froggy.........

word.

[SuperBuickGuy]

I may take it off just the heads - which I have to disassemble anyway to clean up and port
comparing the two

[Stewzer55]

You're really making me reconsider a 4.8 crank in a iron 6.0 block for a high RPM screamer in my '74 with a 427.

[Russell]

using a 20 on one half, a 30 on the other half

I don't know that was possible?

[fatguyzinc]

I may take it off just the heads - which I have to disassemble anyway to clean up and port
comparing the two

dont forget to do the intake too-- ive had them be a bear to fit untill
we planned the mating surface and end rails.
(when you plane the heads, they "sit down" farther into the block,
getting closer together. thus the intake needs to be made "smaller"
if you know what i mean. not always, but its happened more than
once for me, so.....)

[SuperBuickGuy]

It's how real-men get hood clearance none of this "I'll put a shorter manifold stuff"

[silver_bullet]

dual quad air gap with demon carbs?

[fatguyzinc]

It's how real-men get hood clearance none of this "I'll put a shorter manifold stuff"

this ones about ready to go on the 461" in the white vette.
i see your hood clearance and raise you one pollock tunnelram setup.
its a "C-66-O" intake, with twin 2"-4hole spacers and twin 600's......
in the words of tim allen, "arrgh, arrrgh, AAAARRRRRRGH!!!"

*edit* when i originally posted this pic in the $5K or less project section,
the wife walked past, looked at the screen and said "nice--you know the carbs are on backwards,
RIGHT?" i assure you i have since unbolted the carbs and turned them around the right way...

[SuperBuickGuy]

I have lots of cool parts sitting on boxes too .... too easy, my friend, you make it too easy