inline6 Posted February 6, 2011 Share Posted February 6, 2011 (edited) Latest update: Pistons are off for coating. Cam, rockers, springs, etc. are back from cryo treating. Waiting for torque plate for final honing. Nearing having everything ready for final machining. See attached spreadsheet. Make sense to everyone? Hi Pete, I think your gasket volume is off a bit. The head gasket has a bigger bore than the piston diameter, yes? Edited February 6, 2011 by inline6 Quote Link to comment Share on other sites More sharing options...
PalmettoZ Posted February 6, 2011 Share Posted February 6, 2011 I was thinking about using the Isky Z-196 cam: http://www.iskycams.com/pdfcatalog/2004-05/page176.pdf That's the exact cam that I have. I also bought their spring kit/retainers that matches it, and it all goes together correctly and comes with the larger lash caps. The springs are really stiff though, not sure if all that seat pressure is required with that much duration. Quote Link to comment Share on other sites More sharing options...
z-ya Posted February 7, 2011 Author Share Posted February 7, 2011 Hi Pete, I think your gasket volume is off a bit. The head gasket has a bigger bore than the piston diameter, yes? Glad to see someone looked at it. I think it is correct. The bore is 8.7cm, the piston radius is 4.35cm. Gasket volume is: PI*(4.35cm)^2*(0.2cm)=11.89cc Please check again. Thanks, Pete Quote Link to comment Share on other sites More sharing options...
inline6 Posted February 10, 2011 Share Posted February 10, 2011 Glad to see someone looked at it. I think it is correct. The bore is 8.7cm, the piston radius is 4.35cm. Gasket volume is: PI*(4.35cm)^2*(0.2cm)=11.89cc Please check again. Thanks, Pete What is the bore of the head gasket? Same as cylinder bore??? For example, on the motor I am working on now, the bore will be 89 mm, but the gasket will be what... 90.5 mm or 91 mm? Won't make much difference in CR (on my engine calculator, substituting the engine bore for the gasket bore raises my CR by .03), but as long as you are taking the time to do the math... Quote Link to comment Share on other sites More sharing options...
z-ya Posted February 11, 2011 Author Share Posted February 11, 2011 What is the bore of the head gasket? Same as cylinder bore??? For example, on the motor I am working on now, the bore will be 89 mm, but the gasket will be what... 90.5 mm or 91 mm? Won't make much difference in CR (on my engine calculator, substituting the engine bore for the gasket bore raises my CR by .03), but as long as you are taking the time to do the math... I plan on using a copper head gasket with an 87mm bore, but good thinking on the 90.5mm gasket as I might use a 2mm one of those if it makes the CR turn out correct. Here is the block freshly decked, and honed. Next is to install torque plate and final bore to 87mm. Quote Link to comment Share on other sites More sharing options...
z-ya Posted February 11, 2011 Author Share Posted February 11, 2011 That's the exact cam that I have. I also bought their spring kit/retainers that matches it, and it all goes together correctly and comes with the larger lash caps. The springs are really stiff though, not sure if all that seat pressure is required with that much duration. I would trust what Isky provided with the kit. I am using the springs that came in the BSR head I have. They were good for the cam they ran, which is a bit more aggressive than the Isky one we have. I'm looking to have a bit more of a power band. I have a few sets of lash pads, so I should have the correct thickness. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted February 11, 2011 Share Posted February 11, 2011 (edited) I wouldn't trust ISKY's springs just because they're ISKY. When I bought my last cam my machinist warned me about one of the big cam manufacturers, I can't remember if it was Crane or ISKY, the point was the springs were way too strong and they caused premature wear. I had Schneider springs and he was wary of them too, but he checked them on his spring dyno and found them to be OK and put them in. I'm sure some of the machinists/racers around here would have a good idea of what closed and open pressure should be to prevent premature wear. Hey Pete, if you use a larger bore headgasket, you can do more unshrouding of the valves, or you can notch the block to match the head. Just an idea, you know, while you're at it... Edited February 11, 2011 by JMortensen Quote Link to comment Share on other sites More sharing options...
z-ya Posted February 11, 2011 Author Share Posted February 11, 2011 I wouldn't trust ISKY's springs just because they're ISKY. When I bought my last cam my machinist warned me about one of the big cam manufacturers, I can't remember if it was Crane or ISKY, the point was the springs were way too strong and they caused premature wear. I had Schneider springs and he was wary of them too, but he checked them on his spring dyno and found them to be OK and put them in. I'm sure some of the machinists/racers around here would have a good idea of what closed and open pressure should be to prevent premature wear. Hey Pete, if you use a larger bore headgasket, you can do more unshrouding of the valves, or you can notch the block to match the head. Just an idea, you know, while you're at it... Hey Jon, Yea, you're probably right. I know from a reliable source that valve open pressure should be in the 330lbs range. Closed should be around 130lbs. That's for a 0.600 lift cam. I have a set of Crane springs, which I am not using, but maybe I'll ahve the pressure measured. I am using the springs that cam in the BSR C Production head. And as you might expect, the valves are already unshrouded to an 87mm bore, as that is the only bore they ran for an L28 in C Production. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted February 12, 2011 Share Posted February 12, 2011 Is the block notched yet? Quote Link to comment Share on other sites More sharing options...
DrSideways Posted February 12, 2011 Share Posted February 12, 2011 Check Crower for a spring set that meets your spec. You are in the right ballpark for rates. Just like suspension....you want to use the lowest rate possible to do the job. Less wear, less heat, easier on the valve seats. It is stuff like this that where a Spintron would be helpful. Alan Quote Link to comment Share on other sites More sharing options...
z-ya Posted February 12, 2011 Author Share Posted February 12, 2011 (edited) Is the block notched yet? The block doesn't need to be notched because the unshrouded area around the valves matches the 87mm bore. I'm not about to cut the unshrouded area more, and then notch the block. Here is one of the cryo treated and REM/ISF polished resurfaced OEM rockers: Edited February 13, 2011 by z-ya Quote Link to comment Share on other sites More sharing options...
z-ya Posted February 13, 2011 Author Share Posted February 13, 2011 More block boring photos: I should have all the short block components ready for assembly in the next two weeks. Quote Link to comment Share on other sites More sharing options...
z-ya Posted March 6, 2011 Author Share Posted March 6, 2011 Swain coated Cosworth piston: With Carrillo rod: Block ready for assembly: Quote Link to comment Share on other sites More sharing options...
rjstcroix Posted March 6, 2011 Share Posted March 6, 2011 Z-Ya, Awesome looking engine build, very high quality. I call dibs when you want to sell the engine. hahaha You guys are going to clean up in the vintage racing, just like BSR and BRe did when these cars we're new! Wicked! Cheers, RSC Quote Link to comment Share on other sites More sharing options...
1 tuff z Posted March 6, 2011 Share Posted March 6, 2011 pete, didn't know if you knew but i'm about 20 min from dan swain's place. he laughed when i was there to have my lsx headers coated and when i replied to his question as to the cars engine they were for. told me i was a sick man for the hp to wt ratio i'd have in that little z. he's a vette guy himself. Quote Link to comment Share on other sites More sharing options...
z-ya Posted March 7, 2011 Author Share Posted March 7, 2011 pete, didn't know if you knew but i'm about 20 min from dan swain's place. he laughed when i was there to have my lsx headers coated and when i replied to his question as to the cars engine they were for. told me i was a sick man for the hp to wt ratio i'd have in that little z. he's a vette guy himself. Hey David, I knew Swain was in your neck of the woods, but not that close. How is the coating holding up on your headers? These are NOS Cosworth pistons that had an older coating on them. Swain removed the old coating. Good as new now. Ron, bring your check book 8^)... The rods alone go for $300 each at Summit Racing. Quote Link to comment Share on other sites More sharing options...
1 tuff z Posted March 7, 2011 Share Posted March 7, 2011 pete, we used the swain coatings back in 89 when i was a crew chief on a formula continental team-headers and such. i had them coat my sanderson headers back in 2006 and are holding up just fine. they had also coated the header on my L6 supercharged engine and worked great the entire time i had it. Quote Link to comment Share on other sites More sharing options...
z-ya Posted April 5, 2011 Author Share Posted April 5, 2011 Pistons are in. I'm using s Total Seal moly top ring with two piece gapless cast 2nd. Deck clearance matches a document I have written for the BSR C Production engine. Got the gasket from Hussey. Fits really nicely. No coolant between block and head are block. I shouldn't need to do any trimming. $90 shipped. Found this little feeler gauge set. Perfect for measuring lash or determining what lash pads to run: First I took a stock las pad and brazed the recess on the bottom, then ground it flat: Then I smoothed any wear on the top of the stock lash pad: Then I used the little feeler gauge at the lash pad to add height to the modified lash pad, and a normal feeler gauge to set the valve lash: Then check the wipe pattern. Repeat until you get the wipe pattern on the rocker pad. Closer to the pivot pin is better. Safe is right in the middle. Mine turned out to 0.168". So I'm going with 0.170". Quote Link to comment Share on other sites More sharing options...
Noddle Posted April 5, 2011 Share Posted April 5, 2011 (edited) From this picture, it looks like the copper gaskets does NOT use a fire ring, wouldn't the copper 'burn / melt' after awhile ? Nigel Edited April 5, 2011 by Noddle Quote Link to comment Share on other sites More sharing options...
z-ya Posted April 5, 2011 Author Share Posted April 5, 2011 From this picture, it looks like the copper gaskets does NOT use a fire ring, wouldn't the copper 'burn / melt' after awhile ? Nigel It's one big fire ring. Quote Link to comment Share on other sites More sharing options...
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