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Do the LT Motors have the same rocker arm setup as the LS series motors? An if so are you going to be doing a trunnion upgrade or is it already done and if so which route did you go Bronze style bushings or needle bushings?
I’m actually not familiar with LS motors, just the new LT. I do believe they are similar if not exactly the same. I previously did a Comp Cams Trunnion upgrade on the rockers already.
I’m actually not familiar with LS motors, just the new LT. I do believe they are similar if not exactly the same. I previously did a Comp Cams Trunnion upgrade on the rockers already.
So you stayed with a OEM style needle bearing but from a better company?
They are just like ls rockers and both comp cams and CHE make kits for them. The comp are needle bearings that I have seen go out of round while the CHE offering has a bronze bushing setup to replace the needle rollers.
One of the bigger differences I see is that the rocker stands from the ls motors are now part of the cyl. Head, so no fine tuning of the lifter preload can be done other than changing pushrod length. On LS motors, I have used .010 and .020 shims to dial in the preload I want. Very useful on the larger grinds for sure...
Since this is basically the build thread for the second coming of my motor lol, I figure I owe you guys some more photos and a status update. So.... here!
Spent some time disassembling and cleaning the heads up, don’t worry, everything went back exactly as it was taken apart and checked to see if valve lapping was necessary.
Even with the pistons being notched, they will STILL hit the pistons if you don’t bend them out of the way! Before and after shot of bending them. Pistons installed on the rods and ready for assembly. I already have file fit the rings (0.030” top ring, 0.032” second ring,) and checked oil ring gaps and measured oil ring tension. All pistons on the left side done.. And all on the right side done! Getting the cam all lubed up! Yea, its stockish.. Timing set, CMP actuator torqued down. Ready to for lifters! Soaking the lifters.. Cam degreed in and actually may be slightly off from the cam sheet.
They are just like ls rockers and both comp cams and CHE make kits for them. The comp are needle bearings that I have seen go out of round while the CHE offering has a bronze bushing setup to replace the needle rollers.
One of the bigger differences I see is that the rocker stands from the ls motors are now part of the cyl. Head, so no fine tuning of the lifter preload can be done other than changing pushrod length. On LS motors, I have used .010 and .020 shims to dial in the preload I want. Very useful on the larger grinds for sure...
John
The diff in the LT rocker arms is that they are 1.8 the LS is 1.7 I dont know why but was told to use the LT rockers & just get the upgrade from BTR on them. This is what I did I am sure Brian knows what he is talking about on the heads & cam set up. But all LT is set up on 1.8. Robert
ANT, from you doing the cam degree it in correct do you see that it was off really. If so by how much buddy having mine done now on the new forged motor. Robert
Thank you!
-for taking the time to post, add those awesome pics and share your knowledge with us.
Your attention to detail and cleanliness as well as organization will eliminate most if not all issues.
I envy you. And wish you the best with your builds- it’s never just one!
Thank you!
-for taking the time to post, add those awesome pics and share your knowledge with us.
Your attention to detail and cleanliness as well as organization will eliminate most if not all issues.
I envy you. And wish you the best with your builds- it’s never just one!
Thank you, I’m always looking to help out the community. Sometimes that involves trial and error on my part. It ok though.
update:
I degreed the cam, some of the specs were off from the cam doctor sheet unfortunately by about 2 degrees. A cam doctor sheet (not a cam card) is specifically for THIS cam but someone is wrong and may have gotten mixed up with another cam somehow. This means that since this cam has 4* advance ground into it, and the 2* off that I found would retard it, I’ll end up with a cam thats only 2* advanced instead of 4* advanced.
This is ok, but without knowing that ahead of time could have been a problem when tuning. This is why its important to degree the cam!!!! What does this mean? If the car was NA, it would be a bigger deal. Because its a blower car, it simply means I can throw more boost at it earlier. More advance means more power lower in the RPM band, so this means the power will come in slightly higher.
and.... a little bit more **** before we go to bed..
Lifters and trays installed.. Head studs installed and LT4 head gaskets on and ready.. That’s all for tonight. Next will be the heads, then front and rear covers, then the oil pan.
ANT, from you doing the cam degree it in correct do you see that it was off really. If so by how much buddy having mine done now on the new forged motor. Robert
The opening and closing events were off about 2 degrees..
Originally Posted by olblue75
Are the LT4 Heads gaskets better?
they are 2 ply thicker than LT1. Since my heads have been skimmed twice already (ever so slightly upping my compression) the gaskets will help to give a little back to keep compression where I want it.
07-25-2018, 03:35 PM
