What's the best way to tell if the piston is up. I stuck a screwdriver in the hole and it goes in.But the tdc is on 0. Should the screwdriver not go in


Asked by Jun 30, 2013 at 08:56 AM

Question type: Maintenance & Repair

12 Answers


Use caution. Rotate engine over slowly by hand. Screw driver should move in and out of spark plug hole as engine turns. The spot between where the screw driver stops going out and starts going back in is the top of the piston stroke.

1 of 1 people found this helpful.

Thanks the screwdriver is goin in touchin block and the rotor button is at 12 or should it b at 1


What make, model and engine are we talking about. I could possible get you a diagram showing firing order if I knew those things.

dandy his username is 79f100..so maybe a1979 F100 Ford truck? Just a guess....

1 of 1 people found this helpful.

Yes I thought that but several engine sizes listed for that year.

My '78 has a 351W



1 of 1 people found this helpful.

Now that one should cover anything he might have in it. Lol

1 of 1 people found this helpful.

For what it's worth..click to see it......351W

1 of 1 people found this helpful.

Looked back on some of his earlier posts and he has a 351w. DavidH25 is dead on again.

1 of 1 people found this helpful.

Then there you go..now it doesn't have breaker points ya know, but (I know it's not polite to talk about you in 3rd person 79f100) but what do you mean about the rotor being at 12 or 1..like 12 on a clock? That would depend on which way you are looking at it. The rotor should be pointed at #1 with #1 at TDC on compression stroke, and the timing is 6 to 8 before TDC..that image shows it at 12 BTDC I don't know why that is

I looked up the specs and it says 10 BTDC but I have always set mine at 8...and it runs like a champ. Matter of fact I set it by ear. Then if I put a light on it it's always about 8...I get about 10mpg. which is actually pretty good

Your Answer

Add photo

Related Questions


Search Maintenance & Repair Questions

Maintenance & Repair Experts

#1 Tom Demyan
Tom Demyan
Reputation 174,290
#2 dandyoun
Reputation 93,370
#3 tennisshoes
Reputation 75,770
View All

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.