Cylinder Wall - Need Hone And New Rings?

[lilindy500]

This is from my 70 gto motor. Bought the motor a week ago and pulled the heads to check on the condition of the pistons/cylinders etc. Should I hone and put new rings or not worry about it? Supposedly it only had 3000 miles on the motor but I find that a little low...

 

http://s1193.photobu...=IMG_4236-1.jpg

 

It looks like some sort of oxidation, can't feel it with the fingers.

Edited December 1, 2010 by lilindy500 (see edit history)

[BlueAKSSS]

That doesn't look too bad to me, looks like it would run fine, does it have a wear ridge? If you want the motor to be perfect I would definitely pull the pistons, replace rings, lower end bearings probably and hone the cylinders.

[lilindy500]

No wear ridge on the cyl. I'm not to fussy on it being perfect, the rest of the car is far from it for now haha. I am concerned with it loosing compression or something because of the look of the cylinder wall? He said he fogged it when he parked it. Maybe thats residue from fogging oil? I've never fogged an engine so I don't know what it does to the cylinder walls.

[misterp]

From the pic it looks fine, but more info would help. Exactly what pistons were used, and what rings? What I would do, since you have it on an engine stand is to soak a virgin lint-free paper towell in ATF and wipe down the cylinder walls, and turn the motor over a few times by hand to wet the rings in ATF; then put the heads back on it, and using an air compressor and cylinder leakdown pressure gauge (< $100) measure how much leakdown you have in each hole - assuming the builder used common forged pistons & moly rings at 3000-miles break-in it should read about 2.5 - 3.5% leakdown.

 

Love your project, I am an old Pontiac fanatic, the reason I am called "Mr. P." is because when I was in high school I *loved* Pontiacs and my first car was a '77 Bandit T/A with 400 & B/W Super T-10; I also owned a '70 RA III Formula for almost 20-years, built a 428 in that car which was a total animal

 

Mr. P.

[lilindy500]

The pistons are TRW forged. I think they are just the stock replacement, but forged? Rings I am unsure. I will use your advice Mr.P and do a leakdown test, I think my brother has a gauge at his work. Won't happen for a couple weeks, last day of university tomorrow then I write finals for a couple weeks.

 

This past summer I started the project. Bought a 71 Lemans for windows and chrome trim, and I was hoping to use the 400 out of it, it lasted about 30 mins then fall apart. The 70 GTO body has been in my uncles yard since the early 80's. It was just the body, no interior, windows, wiring or nothing. Much like you'd buy a camaro or mustang shell, except this was old. It was fun, I've never done anything like this before, never used a mig, never done body work, and still haven't painted. I have primer to prime the car with, currrently its just in spray bomb primer as I never finished the bodywork in a few spots. TH400 with a 2800 stall should be fun as well. Cam is Advertised Duration 292/292, Lift .490/.490, Pontiac, V8 with 110 LSA (Lunati #00071) and I'm using the Qjet.

[misterp]

The pistons are TRW forged. I think they are just the stock replacement, but forged? Rings I am unsure. I will use your advice Mr.P and do a leakdown test, I think my brother has a gauge at his work. Won't happen for a couple weeks, last day of university tomorrow then I write finals for a couple weeks.

 

This past summer I started the project. Bought a 71 Lemans for windows and chrome trim, and I was hoping to use the 400 out of it, it lasted about 30 mins then fall apart. The 70 GTO body has been in my uncles yard since the early 80's. It was just the body, no interior, windows, wiring or nothing. Much like you'd buy a camaro or mustang shell, except this was old. It was fun, I've never done anything like this before, never used a mig, never done body work, and still haven't painted. I have primer to prime the car with, currrently its just in spray bomb primer as I never finished the bodywork in a few spots. TH400 with a 2800 stall should be fun as well. Cam is Advertised Duration 292/292, Lift .490/.490, Pontiac, V8 with 110 LSA (Lunati #00071) and I'm using the Qjet.

Yeah I ran a set of those pistons in my old 400, they work ok; *probably* they have TRW moly rings, that's pretty standard for the last 20-years. Leakdown test is a godsend, it will tell you exactly what the mechanical condition of the rings & valve seats is - no guessing. But the motor looks good, I would run it.

 

Lunati huh?? Would like to hear it when you get it running again.

 

Mr. P.

[Bear]

I love your project, I am an old Pontiac fanatic, the reason I am called "Mr. P." is because when I was in high school I *loved* Pontiacs and my first car was a '77 Bandit T/A with 400 & B/W Super T-10; I also owned a '70 RA III Formula for almost 20-years, built a 428 in that car which was a total animal

 

Mr. P.

 

That’s too cool, I also had a Gold with Black Bandit Stripes ’78 T/A with the 400 H.O. , BW Super T-10 and 3.42 gears. It was a non T-Top car with no power accessories, with the only thing to make it slower being that it was a Yankee car, it had been ordered with extra insulation (back when you could do things like that). When I picked it up, it was unmolested and didn’t even have the rear of Shaker cut out yet. It ran pretty decent all things considered.

[misterp]

That’s too cool, I also had a Gold with Black Bandit Stripes ’78 T/A with the 400 H.O. , BW Super T-10 and 3.42 gears. It was a non T-Top car with no power accessories, with the only thing to make it slower being that it was a Yankee car, it had been ordered with extra insulation (back when you could do things like that). When I picked it up, it was unmolested and didn’t even have the rear of Shaker cut out yet. It ran pretty decent all things considered.

Mine was 10-years old by the time I got it, it was rough! It had aftermarket T-tops, and 4-spd and 3.73's and I never drove anywhere slower than 75-mph in that car LOL. It was the beginning of a long love of all things Pontiac and loathing of all things law enforcement! I got the car through a trade for a 1978 GMC truck my father gave me, the T/A ran and my truck had a blown engine (my fault!) so it was more a 'needed running wheels' situation but it was literally love at first drive in that car. I built the motor in it, replace the clutch *at least* half a dozen times until finding what would work (still sold today as the Ram Metallic clutch). Two years later I left it in the care of my best friend and when I got it back the T-Top glass was destroyed, and I called all over the country and could not find replacement glass so the car went to the crusher - I cried, I very much remember that day. That experience with that car is so strong with me today still that I am very torn whether I want to get a CTS-V with an auto or a 6-speed, because I really miss rowing gears in that car.

 

Mr. P.

Edited December 2, 2010 by Mr. P. (see edit history)