2.1 Pinto compression expectations

[Fozzy48]

3 hours ago, Snapper said:

What sort of spec is the Head?

if standard I would first do a wet compression test, oil down spark plug hole on the worst cylinder and see if the compression increases.

are you able to do some mechanics yourself? If so you could pull the head off and check a number of things. 

Head gasket

Valve seats, upend Head and put methalated spirits in the combustion chambers to see if it leaks past the valve seats

you don’t say how long you’ve had the 2.1 or how many miles it’s got on it.

Hi mate.

I'm not too bad mechanically and understand how things work, to a certain degree. 

I bought it last June, it's got a big valve head, and RL21 cam in, according to the guy I bought it off, but saying that, he only owned it for few months, but did have a new core plug, head gasket and cam belt put on. I won't truly know this until I look. Trouble with 2nd an 3rd hand descriptions, things get diluted in what has really been done.

It was apparently built as a hill climber and restored about 10 years about ago showing 68k on the clock. I personally don't put too much emphasis on miles TBH, it might have gone round the clock for all I know.

Once I get it to my new house in the garage i can do some checks and tests on it. The engine is coming out once i've found out what the problem is as it needs a new sump gasket and I want to detail the engine bay and engine aswell as move the battery into the boot and other work. So it's no detriment to take it out and strip it if needs be.

One of the tappets sounds a tad on the tappety side, so would expect this one to at least be closing fully. But, this may lead me to find that the rest have been shimmed up too much so may not be closing fully.

Cheers.

Fozzy

[Snapper]

I think we may be going about this the wrong way and perceiving a problem that may not be there.

if you’ve not had the rocker cover off, take it off and look at the back of the cam which should have RL21 stamped in it

ultimately if it’s not producing the power you would expect and a second compression test confirms the low compression you have to take the Head off

[Fozzy48]

32 minutes ago, Snapper said:

I think we may be going about this the wrong way and perceiving a problem that may not be there.

if you’ve not had the rocker cover off, take it off and look at the back of the cam which should have RL21 stamped in it

ultimately if it’s not producing the power you would expect and a second compression test confirms the low compression you have to take the Head off

I personally do not feel as though there is a compression problem, like I say, it feels like the power is there, it just needs setting up properly. 

As it's supposedly got this cam in and big valves, there doesn't seem to be a recognised figure of compression that I should be aiming for. Another thing that bothers me slightly is I don't know as with the previous owner whether it's been changed to lead free and had hardened seats put in. Obviously this puts a bit of doubt in the mind as to whether the valves have burnt and allowing air to leak on the compression stroke. I won't know this until I do the tests that have been suggested. 

Fozzy

[CIRAN CARTON 71]

Have you checked the cam timing?

[Fozzy48]

1 hour ago, CIRAN CARTON 71 said:

Have you checked the cam timing?

TBH I haven't checked anything at the moment mate. The car is kept at my mither inlaws so it's difficult to spend any time looking into it. That will change in a months time when I move into a new house with a garage.

Cheers. 

Fozzy

[CIRAN CARTON 71]

You wnt no anything until you check the basics!!

[Fozzy48]

Right, today along with my best mate we did some tests on the car.

First we did compression tests which read 95 95 100 and 95.

We then checked the tappet gaps. Out of 8 we checked 7 were that tight it was obvious it was going to hold the valves open. After resetting the gaps to 0.025 inlet and exhaust to 0.030 we then rechecked the compression. This then came out at 120 120 122 and 120. 

We then did a leak down test and found that the valves, mostly exhaust are leaking slightly.

After this we put vacuum guages onto the inlet manifold to set the carbs up. 

As it stands the car is more responsive and ticks over spot on.

When I get to my new house we will have the head off and send it to be harden seated.

Why nobles couldn't have done this I have no idea.

Fozzy

[colr6]

You may find after a few miles on it. The compressions may rise a little once the valves have hit the seats a few times and reseated.

[katana]

Result! Whilst hardened seats is the ultimate fix, if they are only slightly leaking then they will probably seal ok with a good lapping. Unless you plan on 10,000 miles a year seat regression is unlikely to become an issue for a few years at least.

[Fozzy48]

25 minutes ago, colr6 said:

You may find after a few miles on it. The compressions may rise a little once the valves have hit the seats a few times and reseated.

I think you're right there Colin. I will recheck them again before I decide on the next move with it.

 

25 minutes ago, katana said:

Result! Whilst hardened seats is the ultimate fix, if they are only slightly leaking then they will probably seal ok with a good lapping. Unless you plan on 10,000 miles a year seat regression is unlikely to become an issue for a few years at least.

It seems a debatable topic this whole hardened seat business TBH mate. On one hand I ask the question, if i take the head off to re-lap them, do I have them hard seated while I've got it stripped for the sake of a few hundred quid. Then at least I know I don't have to do it again in the future.

I'm well happy with the result today TBH and seems like an easy remedy. Not only that, it's all knowledge to take in.

Fozzy

[DT36]

Good job. Can't fault the way a leak off test gives results.

You should feel a difference now out on the road if you thought it was running OK before. Why not get a little time driving it now and have some fun if it feels OK, then maybe pull the head off it next winter. 

 

[Snapper]

reality check pls

After resetting the gaps to 0.025 inlet and exhaust to 0.030 we

shoukd be 0.25mm for both with RL21 or 0.010”

[Fozzy48]

17 minutes ago, dt36 said:

Good job. Can't fault the way a leak off test gives results.

You should feel a difference now out on the road if you thought it was running OK before. Why not get a little time driving it now and have some fun if it feels OK, then maybe pull the head off it next winter. 

 

Oh deffo mate, it's a different car altogether. As for enjoying it and doing garage work in winter, that sounds like a good plan. 

Fozzy

[Fozzy48]

5 minutes ago, Snapper said:

reality check pls

After resetting the gaps to 0.025 inlet and exhaust to 0.030 we

shoukd be 0.25mm for both with RL21 or 0.010”

I hear what you are saying mate. TBH the cam is showing slight signs of wear on the lobes, so for the moment at least I'm happy with the settings we've done. I may need to put a new cam in when I decide to do the engine work and may get a more road friendly one to fit.

Fozzy

[DT36]

I run a Kent FR30 on mine and it pulled well through all gears on my old block. Will let you know how it feels on this new set up, hopefully within 2 weeks. 

[Fozzy48]

Just thought I would post a video of it after the work we did. 

Fozzy

VID-20180330-WA0006.mp4

[DT36]

That is a stunning looking car. 

[Monza]

Sweet

Sent from my SM-G900F using Tapatalk

[mk2dk]

Hi Fozzy

Great result on your troubleshooting.

Your car looks stunning and sounds sweet too

[Fozzy48]

1 hour ago, mk2dk said:

Hi Fozzy

Great result on your troubleshooting.

Your car looks stunning and sounds sweet too

Well thanks for that mate.

I'm dead chuffed with the results and with the troubleshooting seeming to work out. My mate who helped me out loves getting under the bonnet too and is saving to buy one. 

Fozzy