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Author Topic:   blowin engines
number55
Member
posted July 23, 2004 05:22 PM
Hi, not really an engine guy, new at the sport so sorry for the lack of details.

We run a chev/street stock, 355ci, with 64cc heads, 1.94/1.60 beefy springs, solid lifters, 536 lift cam, 500cfm carb. I believe timing was set at 32 degrees. We managed to blow all 8 pistons this week, wholes through 2 of them, engine didn't overheat, didn't over rev. (6200rpm) but destroyed it. 2nd time.

Any advise? Thanks.

H&HMotorsports
Member
posted July 23, 2004 09:23 PM
well good luck running a chavy! all i have to say...and GOOD LUCK


racer17j
Member
posted July 24, 2004 01:11 AM
what is the compression ratio and what fuel are you running sounds like detination to me may be caused by to lean or not enough octain


number55
Member
posted July 24, 2004 03:05 PM
would have to say the compression ratio is around 10.5:1. We were using mohawk gas 90 octane.


racer17j
Member
posted July 24, 2004 04:50 PM
you sure your at 32* what do the plugs look like


number55
Member
posted July 24, 2004 05:52 PM
actually i think it may have been 36* and the plugs didn't actually look bad except for the fact that some of the gaps got so big you could almost stick your finger in there???


rico 08
Member
posted July 25, 2004 07:22 AM
Not enuf octane...some will probably tell you it's fine but you are on the ragged edge with GOOD(oxymoron)93 octane.Years ago it would work but nowdays the pump fuel is really gone downhill,use a good racing fuel around 100 octane rating and it will live.


number55
Member
posted July 25, 2004 03:05 PM
Picked up some av. gas to boost the octane, what kind of ratio would a guy mix? 50/50?


racer17j
Member
posted July 25, 2004 03:31 PM
just run it straight with some marvles mystery oil for lube


number55
Member
posted July 27, 2004 09:36 PM
the av. gas we picked up is 100 not the 110 octane do we still need this marvles mystery oil?


Okie11m
Member
posted July 27, 2004 09:53 PM
yes, it is really dry stuff.


jws
Member
posted July 28, 2004 11:25 AM
Just a note: AVGAS is made to atomize at atmospheric pressures that a plane engine operates at and to burn with a lower oxygen content. At normal pressures the fuel atomization is not going to be ideal and can cause combustion problems. It could also cause a lean condition and burn the pistons. Call a fuel company and talk with someone in there R&D or Tech department and they will advise you are better off using 93 octane and an additive than 110 octane AVGAS.


Ego Racing
Member
posted July 28, 2004 11:35 AM
As for the gagged edge on 90 octane.. We have run 13:1 on 93 octane in Florida with a air temp of 98 degrees and the track at 120 degrees. The car ran at 190 to 210 all day and never had a single problem.


gonfast
Member
posted July 28, 2004 04:14 PM
has anyone used "lucas" fuel treatment as a lube?


Okie11m
Member
posted July 29, 2004 05:23 PM
I just started using lucas this year in my av gas. No probs yet.


bobberpopper
Member
posted August 03, 2004 10:50 PM
quote:
Originally posted by number55:
Hi, not really an engine guy, new at the sport so sorry for the lack of details.

We run a chev/street stock, 355ci, with 64cc heads, 1.94/1.60 beefy springs, solid lifters, 536 lift cam, 500cfm carb. I believe timing was set at 32 degrees. We managed to blow all 8 pistons this week, wholes through 2 of them, engine didn't overheat, didn't over rev. (6200rpm) but destroyed it. 2nd time.

Any advise? Thanks.



I too am into racing in the super steet class. What kind of rear end gear are you running? The wong gear and you will blow a motor real easy, even at 6200 rpm, it cost us 2motors. You need at least a 587 gear.


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