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Engine Mechanical TopicsDiscussion for motor builds, cams, head work, stripped bolts and other engine related issues. The good and the bad. If it goes round and around or up and down, post it here.
If 5cc's need to be removed, no issues whatsoever, providing there is enough dome thickness.
Scott
I was actually planning on calling you guys today when I got home from work. I thought about doing that to the pistons, but again I would have to pay extra money cause of misinformation. I'll call you guys shortly when I get home. Thanks!
not sure why the shop would feel you should pay return shipping?? they should pay (we would if we sold it)
I don't see why they would, cause the kit was correct with the right size pistons, I just seen the description on S&S website and it said 3cc pistons so it was an error on their part, so the company won't pay for their mistake, but I am lol. Whatever, I'll figure it out somehow
I got the Reaper 543's. I was more concerned about the Corrected comp, can I run 9.39:1?
9.6 corrected is not unreasonable but, as I said in my previous, compression releases should be included in the mix. I currently run 9.4 corrected in an all bore 107 and wish had set it up at 9.6. The TMan 600SM cams would have responded well to the increase in compression. I don't see the need to machined the piston dome but that is certainly an option.
I don't see why they would, cause the kit was correct with the right size pistons, I just seen the description on S&S website and it said 3cc pistons so it was an error on their part, so the company won't pay for their mistake, but I am lol. Whatever, I'll figure it out somehow
they should recoup it from S&S,im just telling you what I would do if it was purchased here.no way would I make the customer pay
9.6 corrected is not unreasonable but, as I said in my previous, compression releases should be included in the mix. I currently run 9.4 corrected in an all bore 107 and wish had set it up at 9.6. The TMan 600SM cams would have responded well to the increase in compression. I don't see the need to machined the piston dome but that is certainly an option.
I'll need to do something as you can see ( attached below ) with .030 HG it's way too high and with .040 HG, wouldn't you say that's pushing it? I do plan on installing comp releases. Also running comp that high, does that make the engine not as reliable? Now would it be ok to go with 89cc heads as those ratio's look a lot better lol. I just don't know how making the ports bigger will effect it? Thanks!
Last edited by HardLuck71; Aug 2, 2017 at 02:26 PM.
[QUOTE=HardLuck71;16491849]I'll need to do something as you can see ( attached below ) with .030 HG it's way too high and with .040 HG, wouldn't you say that's pushing it? I do plan on installing comp releases. Also running comp that high, does that make the engine not as reliable? Now would it be ok to go with 89cc heads as those ratio's look a lot better lol. I just don't know how making the ports bigger will effect it? Thanks![QUOTE]
Shaving piston dome or increasing chamber volume or selecting a new cam are all options for lowering compression. I am looking at the situation from the standpoint of what I would do and given your situation, I think I would be fighting harder to get S&S to cover the round trip shipping cost to send the correct pistons. If that is not an option, I would do just what you have done and look at the options listed above.
If the heads are going in to a shop for compression releases and the machinist is capable, you could look at dropping the valves a bit to pick up some chamber volume.
Did you measure deck height or is the .003" an estimate? If an estimate, you should measure; it probably won't make much difference but you should be working with known data while searching for a solution. Another option you might consider is exchanging the 543 gear drive cams for the chain drive cams and installing the a 4* retard pinion sprocket. Install the CYCO shoes to replace the OEM shoes and call it good.
Several options; just have to choose the one that works best for you. Wish I had more to offer but that's all I got.
[QUOTE=djl;16492111][QUOTE=HardLuck71;16491849]I'll need to do something as you can see ( attached below ) with .030 HG it's way too high and with .040 HG, wouldn't you say that's pushing it? I do plan on installing comp releases. Also running comp that high, does that make the engine not as reliable? Now would it be ok to go with 89cc heads as those ratio's look a lot better lol. I just don't know how making the ports bigger will effect it? Thanks!
Shaving piston dome or increasing chamber volume or selecting a new cam are all options for lowering compression. I am looking at the situation from the standpoint of what I would do and given your situation, I think I would be fighting harder to get S&S to cover the round trip shipping cost to send the correct pistons. If that is not an option, I would do just what you have done and look at the options listed above.
If the heads are going in to a shop for compression releases and the machinist is capable, you could look at dropping the valves a bit to pick up some chamber volume.
Did you measure deck height or is the .003" an estimate? If an estimate, you should measure; it probably won't make much difference but you should be working with known data while searching for a solution. Another option you might consider is exchanging the 543 gear drive cams for the chain drive cams and installing the a 4* retard pinion sprocket. Install the CYCO shoes to replace the OEM shoes and call it good.
Several options; just have to choose the one that works best for you. Wish I had more to offer but that's all I got.
I really appreciate your feedback. I used the .003 cause that's what it says on the piston spec sheet, and the thing is, I have the pistons that come with the 98" kit ( 10cc ) I just thought they were 3cc as that's what it said on their site which was an error on their site ( example below ). The 543's I have are chain drive and I was also looking at the 4* gear too. Along with that, I already have TC3 Cam plate & Oil pump, Hydraulic tensioners, Quickee pushrods and hydraulic lifters ( all S&S )
Redo your calculation using the .036" head gasket, 86cc head, .005" deck, 10 cc piston @ your 620'. I got 10.5, right where you need to be according to Fueling. 195.2 ccp
Redo your calculation using the .036" head gasket, 86cc head, .005" deck, 10 cc piston @ your 620'. I got 10.5, right where you need to be according to Fueling. 195.2 ccp
corrected comp is still high at 9.55:1. Didn't know there's a .036 hg?
[QUOTE=HardLuck71;16492317]I really appreciate your feedback. I used the .003 cause that's what it says on the piston spec sheet, and the thing is, I have the pistons that come with the 98" kit ( 10cc ) I just thought they were 3cc as that's what it said on their site which was an error on their site ( example below ). The 543's I have are chain drive and I was also looking at the 4* gear too. Along with that, I already have TC3 Cam plate & Oil pump, Hydraulic tensioners, Quickee pushrods and hydraulic lifters ( all S&S )[QUOTE]
I wouldn't have to think twice. Use all your parts, install the 4* sprocket and retard timing, run a .040" head gasket, install compression releases and corrected CR will be about 9.4 and CCP about 193psi; perfect. Get good tune and call it good.
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