dirty cylinders????
Thread Starter
Racer
Joined: Oct 2001
Posts: 412
Likes: 0
From: Monroe North Carolina
dirty cylinders????
I just had an engine dinoed and it was a dissapointment so when i got home a took the heads off to get ready for better flowing ones. Here is something that I noticed number six is very dirty and number 5 is prefectly clean. here are the pics. What could cause this and is it a problem?
Drifting
Joined: Oct 2004
Posts: 1,259
Likes: 7
From: Ontario
You can't have much time on this engine....marker still there. Ignition issue is my guess. A dead cylinder would certainly pull down your HP and more than 1/8th.
PS...what thread sealer did you use...I see white marks around the bolt holes?
PS...what thread sealer did you use...I see white marks around the bolt holes?
Thread Starter
Racer
Joined: Oct 2001
Posts: 412
Likes: 0
From: Monroe North Carolina
no the engine was only ran for about 45 total minutes. at 3500 rpm it made only 256 HP. It seems that if one entire cylinder wasnt firing someone it the engine dyno room would have noticed also 2 different distributors were used. Seemed like pretty knowlegable engine people running the shop.
I used Permatex high temp tread sealer.
I used Permatex high temp tread sealer.
Drifting
Joined: Oct 2004
Posts: 1,259
Likes: 7
From: Ontario
Originally Posted by Corvettelvr73
no the engine was only ran for about 45 total minutes. at 3500 rpm it made only 256 HP. It seems that if one entire cylinder wasnt firing someone it the engine dyno room would have noticed also 2 different distributors were used. Seemed like pretty knowlegable engine people running the shop.
I used Permatex high temp tread sealer.
I used Permatex high temp tread sealer.
If not ignition...how is the valve train? Is the intake opening properly?
Last edited by Retro78; Feb 20, 2006 at 12:48 AM.
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Race Director
Joined: Apr 2000
Posts: 17,676
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
Originally Posted by Corvettelvr73
no the engine was only ran for about 45 total minutes. at 3500 rpm it made only 256 HP. It seems that if one entire cylinder wasnt firing someone it the engine dyno room would have noticed also 2 different distributors were used. Seemed like pretty knowlegable engine people running the shop.
I used Permatex high temp tread sealer.
I used Permatex high temp tread sealer.
Thread Starter
Racer
Joined: Oct 2001
Posts: 412
Likes: 0
From: Monroe North Carolina
Originally Posted by MotorHead
What was the HP at 6000RPMs ? Why only take it 3500RPMs ? My motor only made 350HP at 3500RPM but at 6500RPM it made 546HP almost 200 HP more so who knows you could easily be at 400HP at 6000RPM and if you hook a spark plug up to cylinder 5 maybe 450HP
At first they thought that the plugs were too hot (R45t)
Put in R43T and still stumbling (missing) under load above 4500 rpm
Next thought that the unilight module in the distributor was at fault
tried a new distributor and still missing.
Blamed the edelbrock performer 750
put on a holley and it made one stumble free pull and 256 Hp at 3500 rpm was the highest hp
SOOOO... Now i have a torn apart engine again and dont know if i need a new carb, or a set of better flowing heads and a stouter cam or If I should blame the dyno shop for letting it run on 7 cylinders and try to get my money back
I am running 882's with the 2"-1.6" valves and a crane energizer 270H
Last edited by Corvettelvr73; Feb 20, 2006 at 02:24 PM.
Race Director
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
Just something that might interest you, I put in a brand new set of plugs once and one cylinder wasn't firing. I changed that plug and everything was OK. The brand new plug was defective, it didn't fire