Type of fuel

Lefty · August 14, 2013, 07:47:17 PM

Hi,
Just a quick one. I was searching for a previous answer to this question but could not find in the forum. I have a 1979 vet, 350 engine.

What type of petrol does everyone use. I was using 98 and was advised 95 would be better for the motor and there wasn't a noticeable difference in performance. Are there any other opinions?

Cheers Lefty

MY081 · August 14, 2013, 08:04:09 PM

Iuse 98, but not Shell fuel my car goes onto 7 cylinders. Other members have had the same problem.

Camo · August 14, 2013, 08:19:26 PM

I concur. The Shell fuel seems to create havoc with carby fed engines. I'm no fuel expert but I would say in depends on the compression of your engine. My Vette runs 11:1 compression and a bit of a cam. I have run it on 95 when I've had no choice but If I get into it it will ping it's head off. I would guess that if you motor is a lower compression unit it would be ok on 95.

Lefty · August 14, 2013, 08:27:01 PM

I was reading the for mum post http://nswcorvettes.com.au/forum/index.php/topic,3450.msg1045912742.html#msg1045912742

Which I think was one of yours cam, from BP. This was interesting, the recent issue I had with the hesitation could be put down to using 98.

I wonder if there is a fuel supplier out there who provides suitable fuel for our engines?

Lefty

gtc · August 14, 2013, 08:29:17 PM

I use Caltex 98 in my 454. The previous owner warned me against using Shell V-Power as the engine definitely doesn't like it.

I've heard some reports of Vette engines running a tad hot when using 95.

If the engine is in good condition and good tune, then you should get better economy on 98 than 95.

(Economy is not something I bother about. I use a tankful on a day out anyway LOL!)

Camo · August 14, 2013, 08:36:18 PM

Yep that's one of mine from the early days. I did a bit of testing when we did the new motor in Priscilla. Took samples at different stations as well as tried them in the car. I found I had problems with BP and more so with Shell but no hassals with Mobile and Caltex 98's. I also found quite different fuels at different stations. Yeah yeah I know I'm anal, but had too much money wrapped up in the motor. I settled on a station in my area which has a good turn over in fuel and it's fuel is always nice and clean. A Caltex. When out of town I always try to use Caltex or Mobile.

Quote from: gtc on August 14, 2013, 08:29:17 PM

......(Economy is not something I bother about. I use a tankful on a day out anyway LOL!)

Camo · August 14, 2013, 09:01:25 PM

Lefty, just read your post on your hesitation issue. Just a thought, if you now have new hotter plugs and she's running ok you should periodically pull a couple to see how they are running. It's a good indication of how your motor is running and you can pick up potential problems well before they get too bad. Once all is ok you wont have to worry until service time.

You burning any oil?

Lefty · August 14, 2013, 09:25:05 PM

Thanks cam, that is good advice and the plan going forward. It's been a learning process and just a few basics I think are good starting points,
Check plugs and replace if in doubt,
Use fresh petrol and determine the best one for the car,
When you get the car converted or the power steering pump changed, change the plugs that will be inaccessible during this process,
Drive the car and check plugs until it is tuned to run well.
If you can't diagnose or tune, make sure you have someone who can.

Lefty

Lefty · August 14, 2013, 09:27:33 PM

RE the oil, it does not appear to be burning oil just leaking it from the back of the engine, have fixed most leaks this is should be the last one. ( do corvette ever stop leaking?)

Cheers

Lefty

Camo · August 14, 2013, 09:35:05 PM

Yep they do stop leaking, when the oil runs out

Rear of the motor.... rear main possibly, that's no fun. But check the back of the valley cover (intake manifold) dissy where it fits into the block and of course the back of the tappet covers. Access to a car hoist really helps. What area do you live in?

bfit · August 14, 2013, 09:50:20 PM

Quote from: Camo on August 14, 2013, 09:35:05 PM
Yep they do stop leaking, when the oil runs out

Rear of the motor.... rear main possibly, that's no fun. But check the back of the valley cover (intake manifold) dissy where it fits into the block and of course the back of the tappet covers. Access to a car hoist really helps. What area do you live in?

Good advice
If oil is coming from high in the motor your in luck
In two piece rear min seals you can chance with crank in place
But not easy
It involves lowering th crank and rotating the top half seal
If its a rope seal crank out job
Bfit

Camo · August 14, 2013, 10:03:21 PM

If he drops the inspection cover on the bell housing he'll soon know if it's the rear seal or not.

Always pays to give the motor a good clean when chasing oil leaks. Brake cleaner works a treat. Don't have to wash the motor with water and it drys really quickly. NOT to be done on a hot motor.

Lefty · August 15, 2013, 04:56:23 PM

Cam.

The oil leak hits the top of the exhaust just in front of the driver ( note rod conversion), ill investigate and see what it looks like. There are few bits to fix and ill get to them soon.

Many thanks

Lefty

bfit · August 15, 2013, 05:34:08 PM

Quote from: Lefty on August 15, 2013, 04:56:23 PM
Cam.

The oil leak hits the top of the exhaust just in front of the driver ( note rod conversion), ill investigate and see what it looks like. There are few bits to fix and ill get to them soon.

Many thanks

Lefty

Mate on some cars there is a oil line that comes from the Block just above he filter worth a look at if your engine has it
Bfit

Camo · August 15, 2013, 07:51:01 PM

Quote from: Lefty on August 15, 2013, 04:56:23 PM
Cam.

The oil leak hits the top of the exhaust just in front of the driver ( note rod conversion), ill investigate and see what it looks like. There are few bits to fix and ill get to them soon.

Many thanks

Lefty

What area you live in Lefty? I only ask as I have a hoist that you are more than welcome to put your beast up on to have a look underneath, if you already don't have access to one.

The hoist is at Ingleburn.

Lefty · August 15, 2013, 08:00:23 PM

Many thanks cam that's a very kind offer, in at Croydon. I may just take your on this if I can't determine the issue.

Many thanks

Lefty

Camo · August 15, 2013, 08:06:32 PM

No probs. I'm retired so pretty well free most days, if I'm not out cruising.

StephenSLR · August 15, 2013, 08:39:14 PM

I went to the carby centre in Burwood and the guy told me to run it on 95, he said 98 is best for modern motors with fuel injection, etc.

Then you get it tuned with 95 in the tank, if you don't have an octane sensor it won't adjust when you change it to 98.

Someone else told me valve lube additive makes it run smoother even though he has hardened seats.

s

Lefty · August 16, 2013, 09:12:41 AM

Steven,
Do you favour a particular brand of petrol?
Lefty

StephenSLR · August 16, 2013, 09:21:57 AM

Quote from: Lefty on August 16, 2013, 09:12:41 AM
Steven,
Do you favour a particular brand of petrol?
Lefty

I usually go to Caltex or Shell due to shopper dockets, lol.

I can't really spot a difference between the two and haven't had the issues other people have with fouling plugs, etc. I don't use 98 so not sure if that has something to do with it.

Online I hear differing accounts and it depends on which region you get your fuel from as to which one is better.

I only hear good reports about BP Ultimate though.

Edit: I also use the Nulon valve lube.

s