Help on Milled Heads
HDF Community Team
Joined: Jun 2006
Posts: 12,774
Likes: 2,606
From: san antonio
I selected -1.00cc dome volume out of ignorance, BigBoyz says flat top pistons range from -1.0 - -1.5 so I selected -1.0. I do plan to cut the cylinders to a 0.00" deck. I would love to swap the cams, I really do not care for the SE-203's, unfortunately the ole lady is trying to pull in the reins on the cost of this project. If the stars align, I may be able to sneak an additional $300 for the cams. However, lets say that doesn't happen and I then plan to replace the cams next winter, what is the worse that could happen running a higher static compression with the 203's? If it could mean ruining the motor, maybe I just slap an OEM head gasket on for now to lower the compression and then next winter I can swap the cams and the head gasket?
I was measuring the valves last night, the intake measures 2" and exhaust measures 1.615", seems a bit higher than the average over sized I have been seeing in the forums. I am not sure if that changes a few factors or not?
I was measuring the valves last night, the intake measures 2" and exhaust measures 1.615", seems a bit higher than the average over sized I have been seeing in the forums. I am not sure if that changes a few factors or not?
My comments regarding compression and the SE203 cams is based on my experience with SE204 cams which is not a fair comparison. The SE204 cams have an intake close 2* earlier than the 203s and also has 8* advance ground into the intake and exhaust profile where the 203s have 1.8* ground in advance. The larger valve reliefs will help with bring down compression as they will be 2cc-3cc now instead of 1.5cc; you should check with Scott on that. You may be OK with the 203s at 10+:1 static compression, I can't and wouldn't want to say for sure having never run the SE203 cams at that compression. However, I do suggest that you only run premium fuel and listen for ping and be prepared to back out some timing to address any detonation should that become an issue. Good luck and let us know how it turns out.
I would still toss the SE203 cams at the first opportunity and replace them with a better choice; still like the S&S570 or the Andrews 57 which I believe is available for early chain drive. It is not listed in the catalog but is available, just have to call to order.
Last edited by djl; Feb 22, 2018 at 09:16 AM.
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Intermediate
Joined: Jun 2017
Posts: 29
Likes: 2
From: Wisconsin
I have the woman on board for replacing the cams with an S&S 570. I am just waiting on the pistons to be delivered and then I will be tearing her down and bringing everything to the machinist. I am excited to see how this all turns out!
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Intermediate
Joined: Jun 2017
Posts: 29
Likes: 2
From: Wisconsin
Going with the S&S 570, part number 330-0003 states that I need a high lift spring kit. Did you require these? If so, what did you get?
Advanced
Joined: Dec 2017
Posts: 53
Likes: 4
From: Southern Maine
I did not require them because I have '06 heads which are said to be good to around .590 lift. 99-05 heads with OEM springs need hi lift springs in order to run the S&S 570. What year are the heads you were planning on using? Also, I thought in your first post you said the heads were rebuilt with new springs. Do you know what springs they are? They might work. If I were going to replace the springs in though, I'd get the S&S .585 springs (p/n: 900-0594). They can be had on ebay, new for around $98.
Advanced
Joined: Dec 2017
Posts: 53
Likes: 4
From: Southern Maine
http://www.bigboyzheadporting.com/showthread.php?t=83
This article will show you how to check the heads to see the casting date if you don't know what to look for.
This article will show you how to check the heads to see the casting date if you don't know what to look for.
HDF Community Team
Joined: Jun 2006
Posts: 12,774
Likes: 2,606
From: san antonio
I did not require them because I have '06 heads which are said to be good to around .590 lift. 99-05 heads with OEM springs need hi lift springs in order to run the S&S 570. What year are the heads you were planning on using? Also, I thought in your first post you said the heads were rebuilt with new springs. Do you know what springs they are? They might work. If I were going to replace the springs in though, I'd get the S&S .585 springs (p/n: 900-0594). They can be had on ebay, new for around $98.
As Cody suggests, check the casting number but since the heads have been worked, the casting number may not mean much. Have your head guy check valve lift and valve stem diameter; he should know what to look for. Plenty of replacement options if new springs are required for the higher lift, just keep seat pressure close to that of the OEM beehives and avoid high spring pressures which will just add to valve train noise. I forget what the seat pressure of the OEM beehive springs is but you don't need much more than that in an aftermarket spring. The S&S .585" springs might be fine and might be cheaper than OEM; not sure about that or the seat pressure though.
Seasoned HDF Member
Joined: Dec 2005
Posts: 19,868
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From: poway
I did not require them because I have '06 heads which are said to be good to around .590 lift. 99-05 heads with OEM springs need hi lift springs in order to run the S&S 570. What year are the heads you were planning on using? Also, I thought in your first post you said the heads were rebuilt with new springs. Do you know what springs they are? They might work. If I were going to replace the springs in though, I'd get the S&S .585 springs (p/n: 900-0594). They can be had on ebay, new for around $98.
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