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A 521 in Massachusetts


Crashtd420

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  • 1 month later...

Even though it's winter I was able to take the truck out for the afternoon yesterday... it was almost 60 out and about the same today...

Might take it out once more to pick up my son later.....

And we should have snow on monday....

 

Not much planned for the truck right now... I need to give the truck a once over and its yearly greasing. I also need to get a mat for the bed and possibly 2 tires before inspection in may.... I had the toe adjusted incorrectly and wore the outer edge ... I have corrected it but I feel like I should have it properly checked this time....

 

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One thing I have always wanted to do since I built the engine was a compression test....

While I was happy with the consistency I was very surprised of the number.....

I got 240 psi across all 4 cylinders....

Seemed high to me at first but after looking around seems like it is good for a higher compression engine....

 

Since my engine is around 10.5-1 cr does 240 psi seem like a good corresponding number for a compression test?

 

And as a side note the engine now has 20,000 miles on it...

Edited by Crashtd420
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1 hour ago, Crashtd420 said:

One thing I have always wanted to do since I built the engine was a compression test....

While I was happy with the consistency I was very surprised of the number.....

I got 240 psi across all 4 cylinders....

Seemed high to me at first but after looking around seems like it is good for a higher compression engine....

 

Since my engine is around 10.5-1 cr does 240 psi seem like a good corresponding number for a compression test?

 

And as a side note the engine now has 20,000 miles on it...

 

It runs well? no pinging on Regular?

Did you perform it with a wide open throttle?

My chevy racer engine is 10.5 - 1 and pumps 180 psi

I would recheck that psi with another gage

 

 

362641d1501209207-hypothetical-wrong-compression-ratio-comp-ratio-psi-3232384013.png

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At cranking speeds a 'race' engine would likely have a larger overlap and much later intake closing. A 620 L20B intake closes at 520 ABDC or that much of a crankshaft turn up the cylinder. Compression begins when the intake closes. The intake on an L16 cam in the 620 closes earlier at 480 so would have higher compression at cranking speeds.

 

On an L20B 85mm piston 240 PSI would require the starter to compress over one ton of compression at/near TDC. Is that possible?

 

 

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I don't know anything other than what I see....

The 240 psi was on a warm engine...

I checked again right now and it was 220 psi on a cold engine....

 

This is an l16, 84mm 9cc dome pistons , w53 closed chamber head with this cam.....

 

Screenshot_20240211_145920_Gallery.thumb.jpg.d64d48413e453132e65d526af176a154.jpg

 

Also I have always ran 93 octane and never experienced any pinging or detonation....

 

I do plan to verify the valve lash as I have read that can effect the test... 

Then check it again....

I'll have to see if I can borrow another gauge for comparison but my gauge should be correct and I have only used it a couple times....

Edited by Crashtd420
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  • 3 weeks later...
49 minutes ago, pidge said:

Same weather up here in Ontario today (Toronto region). Can’t remember such a mild winter ever. Trucks lookin good man. 
-Pidge

Appreciate it....

I'd drive it more but the salt they put down in the winter is horrible.... I can see it all down my nissan... it rained really good the other day so every thing washed away....

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I dig the whole stance of your truck. What’s that wheel size/tire combo + lowering situation you have going on? Those wheels are the perfect spacing especially. I know I know I could read through the previous 200 pages and find out (and I probably have and forgot). 

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56 minutes ago, Slow Loris said:

I dig the whole stance of your truck. What’s that wheel size/tire combo + lowering situation you have going on? Those wheels are the perfect spacing especially. I know I know I could read through the previous 200 pages and find out (and I probably have and forgot). 

Thanks....

Rims are 15x8 I believe not sure the offset....

Tires are 195/60r15....

Tires are supposed to be a match to the original diameter but that has been debated on what diameter that actually is... 

 

As for the suspension I'm on coilovers all 4 corners... and I'm not sure where the factory ride height should have been to start....

 

I think I'm around 2 inches or so in the front, I have about a 1 inch gap to the bottom of the fender....

Rear is about 3 1/2 inches.... again I just set a gap I liked to the bottom of the fender.. I think the rear gap is about an 1 1/2 inches...

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Got off my butt today and worked on the truck a little.. weather is starting to get nice and I'm driving the truck every so often....

Gonna try to grease all the grease fittings tomorrow...

Today I finally went and checked the valve clearances.... very slight adjustment but everything looked good...

 

 

20240309_170732.jpg

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I got to take the truck for a drive today...

It's funny how such a slight adjustment makes the engine sound quiter....

 

When I got back I greased up all 25 or so grease fittings... such a pain but I try to do it yearly....

Also adjusted the emergency brake....

 

 

 

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  • 2 weeks later...

Well I have to park the datsun till I replace the front tires....

I have been sneaking it out on some of these nicer days only to realize how shitty my front tire is....

 

20240320_161604.thumb.jpg.e2bb1e17ac918531b14c75924a7d193e.jpg

 

Obviously an alignment issue... 

I have since redone it in my garage but the damage was already done....

 

Debating on getting it properly aligned this time.... I know where my error was and it was my own fault but I have no gauge to say I'm correct how it is now...

The way I do it I feel might be introducing some added variables...

 

I'll obviously have to recheck with the new tires, so that's why I'm thinking I might pay this time... figure when I get home I can compare what they did to my garage method and see how close I am... that will establish a good base line for future garage alignments ... guess I just gave myself the reason why I should....

 

Also trying something new getting tires....

Since money is tight I was looking on ebay and found a good pair of tires for $110... tires all seemed to be discounted a good 25%.... and I saw they offer tire installation and at discount. Getting 2 tires mounted and balanced, valve stem and disposal for $50... around town it is 40 to 50 per tire.... if this goes well I'll probably get 2 more coming for the rear next month...

 

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5 hours ago, Crashtd420 said:

Well I have to park the datsun till I replace the front tires....

I have been sneaking it out on some of these nicer days only to realize how shitty my front tire is....

 

20240320_161604.thumb.jpg.e2bb1e17ac918531b14c75924a7d193e.jpg

 

Obviously an alignment issue... 

I have since redone it in my garage but the damage was already done....

 

Debating on getting it properly aligned this time.... I know where my error was and it was my own fault but I have no gauge to say I'm correct how it is now...

The way I do it I feel might be introducing some added variables...

 

I'll obviously have to recheck with the new tires, so that's why I'm thinking I might pay this time... figure when I get home I can compare what they did to my garage method and see how close I am... that will establish a good base line for future garage alignments ... guess I just gave myself the reason why I should....

 

Also trying something new getting tires....

Since money is tight I was looking on ebay and found a good pair of tires for $110... tires all seemed to be discounted a good 25%.... and I saw they offer tire installation and at discount. Getting 2 tires mounted and balanced, valve stem and disposal for $50... around town it is 40 to 50 per tire.... if this goes well I'll probably get 2 more coming for the rear next month...

 

I hate buying tires….

 

We have a mobile place here that was convenient, but not cheap… and wouldn’t “stretch” a 205 to a 8” wheel… not really even a stretch…

 

Went to Hogan for my last set but they scratched my new wheels- not terribly or even really noticeable but annoying. They do atleast off lifetime balance on them which is convenient for the all terrains on my Tacoma.

 

Did tire rack to the performance shop for the last set I had mounted for the 510 but install was really expensive!

 

going to need another set for the 510 probably next year… but the z should be good for a good 5+ years now based on my mileage 

Edited by demo243
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On 2/11/2024 at 12:07 PM, Crashtd420 said:

I don't know anything other than what I see....

The 240 psi was on a warm engine...

I checked again right now and it was 220 psi on a cold engine....

 

This is an l16, 84mm 9cc dome pistons , w53 closed chamber head with this cam.....

 

Screenshot_20240211_145920_Gallery.thumb.jpg.d64d48413e453132e65d526af176a154.jpg

 

Also I have always ran 93 octane and never experienced any pinging or detonation....

 

I do plan to verify the valve lash as I have read that can effect the test... 

Then check it again....

I'll have to see if I can borrow another gauge for comparison but my gauge should be correct and I have only used it a couple times....

 

This sounds insanely high. Try another compression gauge.

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23 hours ago, Stoffregen Motorsports said:

A friend of mine told me he buys name brand tires off Amazon. I haven't yet checked the viability of that solution, but it sounds like he's saving tons.

 

I actually just found another good deal....

Everyone wants 100 to align the truck even if it is in spec...

Firestone will check it on the machine for around $25-$30.... no adjusting....

I'll be able to make adjustments from their readings after if necessary....

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1 hour ago, Crashtd420 said:

 

I actually just found another good deal....

Everyone wants 100 to align the truck even if it is in spec...

Firestone will check it on the machine for around $25-$30.... no adjusting....

I'll be able to make adjustments from their readings after if necessary....


Might have to keep that in mind for the  Z - everyone wants $100+ and currently the only adjustment is toe- I’ve got a new rack and tie rods to go on and I can get it close at home with a tape measure… and then I’ll know where the camber is at too once I get the coilovers on. 

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