Another old car thread

[swampratt]

Did you do the carb?
I have been thinking of going to E85, so far it is just thinking.
So 13.0 compression and slightly radical cam .. cam sounds like a 245@ .050 or so possibly less.
I have not done any 400" small blocks.

Have you checked the cranking pressure on that ..
I know E85 likes a lot of compression to be at it's best but my theory was all about actual pressures.

So I have not seen what the E85 guys run for cranking pressures.
My old 78 nova with a 350 had 12.02 actual compression and I ran it on 91 octane at 38 total timing and 93 octane got 41 total timing.. this is when the super unleaded was pink. This is with iron heads.
That engine had a 270 comp cam [email protected] and had 245PSI cranking pressure.

That is why I ask if you have checked yours?
My current 350 with the 268 comp with a very early closing intake valve has 225 PSI cranking pressure and this is just a tick over 10.5 compression.

Sorry I am ate up with it I know.

 

[gfercaks33]

I sent the carb off to a guy raceone85.com is his site. With switching to e85 higher octane gad was way up there around $4 I believe and e85 was new it was about $1.25 a gallon but there were only 2 stations. A lot of people talk about how corrosive and how it ruins every thing, that's not the case and most people haven't used it that say that stuff. I'm running a plastic fuel cell and steel braid, the only issue I had is if you let it sit in the carb too long it gels up and the o rings on my fuel filter became brittle when I took it off but I'm not positive that was because of the e85
.
This is my first build and had a friend help. Just from the specs from the Pistons is where I got my compression and I haven't auctually ran a compression test.

You were very close with the guess on the cam
http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=89&sb=2


Here's a pic when the engine was built so you can see the dome on the piston

 

[gfercaks33]

Just saw this when I updated an old thread, in May I took the car to a Dyno shop and it made 300 hp and 400 ft/lbs of torque. Well those numbers are a bit skewed because shortly after the Dyno I was messing with it and ran a compression test and had one cylinder was much lower than the rest. I'm 90% sure I washed the piston ring when I had carb issues.

 

[swampratt]

Do a wet compression test if you have not and see if it is the rings or possibly valve seal issues.

My engine ran 11's but not deep enough to beat my V65.. was off by .1 second.
I knew i could beat that Honda so i knew something was wrong..245psi on all cylinders except one of them..which had 60 psi.
Intake valve guide was elongated and lost a good seal on the valve.

 

[gfercaks33]

I ran the wet compression test and it jumped from the 160 it was to almost 190 (like the rest of the motor) so I believe it's the piston rings. A buddy of mine mentioned the last ditch effort of putting some thick oil down the cylinder and run it, he said sometimes it will reseat the ring.

 

[SoonerP226]

FWIW, O-ring brittleness is a classic symptom of ethanol in the gas. You might want to make sure any rubber fuel lines are ethanol-rated, as well the replacement O-rings.

 

[gfercaks33]

FWIW, O-ring brittleness is a classic symptom of ethanol in the gas. You might want to make sure any rubber fuel lines are ethanol-rated, as well the replacement O-rings.

These are the moly piston rings we are talking about, also I'm running e85 so it's almost all ethanol in my fuel system.

 

[SoonerP226]

and the o rings on my fuel filter became brittle when I took it off

Those are the o-rings to which I was referring. (It's in post #12; for some reason, I can't "reply with quote" on this machine, so there's no backtrack link.)

 

[gfercaks33]

I got you now. I have 2 print on the entire system and they are in the filter, I replaced them with the "green" ones in hopes they will last longer.

 

[dennishoddy]

Green = viton o rings.
Ethanol and buna rubber o rings don't work.