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Post by crazycunuc on Aug 30, 2018 12:23:10 GMT -5
Hats off to you.. this is looking great! Keep up the good work and updates!
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Post by ducdon on Sept 28, 2018 22:47:00 GMT -5
Gathering data for engine mods. Port Timing, Deck Height and Squish. I want to do some porting. Not to make significant changes to timing, just to to equalize and match. Everything varies so I'm not sure where to start? Sure like to hear some advice???
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Post by Walms on Sept 29, 2018 9:12:08 GMT -5
How did I miss this thread? Nice looking project so far! H1’s definitely need to be decked! I think stock is 2mm if not a bit more!
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Post by ducdon on Sept 29, 2018 17:57:48 GMT -5
YES. I measure the deck height at 0.060 (1.5 MM) plus .020 gasket for 2mm total. My dilemma. Is the first operation to cut the deck height?
Cylinders vary in height (From base to deck) and top of exhaust port to deck also vary. Correcting one would just make the other worse. Variances not big. About 0.010. Everything I read says to cut top of exhaust port to a distance from the deck? Guess I'll just have to wait till I get cylinders bored and pistons installed!
CHEERS
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Post by Walms on Sept 29, 2018 19:33:52 GMT -5
I would use the base of the cylinder as your datum and deck all cylinders so that you have 1mm from the edge of the piston to the “deck”. I’d make all 3 equal and I’d use a .020” thick copper gasket to get your base measurement. After you decide what you want to do for your port timing, you’ll need to calculate the head volume to produce about 150 psi cranking pressure.
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Post by Walms on Sept 29, 2018 19:36:13 GMT -5
Sorry I didn’t really answer your question correctly, yes old school measurements are from deck down for port timing but not good imo as deck heights varied so much.
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Post by ducdon on Sept 29, 2018 21:04:10 GMT -5
I would use the base of the cylinder as your datum and deck all cylinders so that you have 1mm from the edge of the piston to the “deck”. I’d make all 3 equal and I’d use a .020” thick copper gasket to get your base measurement. After you decide what you want to do for your port timing, you’ll need to calculate the head volume to produce about 150 psi cranking pressure. So if I read you right I'd finish with a squish of 1.5MM? My plan was to shave the heads and cut a new squish band 8 to 9 mm wide, then open up the chamber to get a suitable compression ratio. I have a number of damaged heads I can practice on. Old chamber volume by my measure is about 17.5cc. Will need to be significantly larger after decking the cylinders. It's my first time through this exercise. I appreciate the advice.
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Post by Walms on Sept 30, 2018 16:39:22 GMT -5
Sorry, you need to set squish to 1mm so .5mm piston to deck. If you plan to raise exhaust port, this will lower compression and needs to be compensated.
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Post by ducdon on Nov 5, 2018 16:54:57 GMT -5
Not a lot of progress lately. I did receive new pistons and will get on to having the cylinders bored shortly. In the mean time I machined a fixture to hold cylinders in the lathe. Based on measurements using old pistons I'll have to remove material from the cylinder deck in order to get a decent squish clearance.
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Post by ducdon on Nov 19, 2018 21:03:55 GMT -5
Spent some time today experimenting with head mods. Pioneering work for me. If anyone has knowledge or experience with this please do comment.
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Post by ducdon on Dec 10, 2018 14:32:04 GMT -5
Completed machining of new squish band and chambers on 3 cylinder heads. They CC out at about 22CC. I'm hoping that's a bit big and a final trim will bring them down to whats needed for 145 to 150 lb cranking pressure. My best guess is the final number needs to be about 20cc to go with 1mm decking of the cylinders? Cross my fingers.
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Post by ducdon on Feb 11, 2019 22:21:43 GMT -5
I finally got new pistons and had the cylinders bored. Milled 1mm of the tops of the cylinders to get the correct squish height.
Top end assembled. At some point I will have to remove the heads and skim them to get the correct cranking pressure.
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Post by Walms on Feb 12, 2019 6:26:57 GMT -5
Looking great!
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Post by crazycunuc on Feb 15, 2019 14:55:25 GMT -5
Very nice!!
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Post by ducdon on May 26, 2019 20:11:43 GMT -5
Finally gathered all the bits to rebuild my oil injection pump. When I went to hook it up the threads for the oil input banjo were mostly stripped, so I had to take it apart for the second time to Heli-Coil some new ones. Set up a test by running the pump through the tach drive gear train. It works. Onward and upwards.
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