Results 1 to 12 of 12
Thread: G5X3 PTV 243 and 853
-
04-27-2011, 04:16 PM #1
- Join Date
- Apr 2009
- Location
- Pennsylvania
- Posts
- 285
Pewter- 2000 Camaro SS
G5X3 PTV 243 and 853
Here are the numbers i have with the 243
Exhaust BTDC
15 deg .150
10 deg .109
5 deg .085
0 deg .078
Intake ATDC
0 deg .049
5 deg .057
10 deg .080
15 deg .129
With the 853 heads
Exhaust
15 deg .202
10 deg .155
5 deg .130
0 deg .121
Intake
0 deg .069
5 deg .076
10 deg .103
15 deg .146
I beleive the tolerance for the intake is suppose to be .080 and for the exhause .100. According to my readings i cannot use either head on with this g5x3 112lsa.
Does anyone have any opinions on the numbers i have come up with.
I am using the stock lifter, so maybe this is the issue. I am going to the dealer tomorrow to buy one and make it solid.
Any opinions??????
-
04-27-2011, 07:41 PM #2
Are you rotating the engine and using the valvetrain with a dial indicator on the rocker??
If so you'll need a solid lifter or a dummy lifter to accomplish that. Even a hydraulic lifter full of oil will still compress and give false readings.
You can take a hydraulic lifter apart and stack washers inside to make it solid if need be.
-
04-28-2011, 01:04 PM #3
- Join Date
- Apr 2009
- Location
- Pennsylvania
- Posts
- 285
Pewter- 2000 Camaro SS
Ok i went and purchased the lifters and made them solid. With the 853 heads at TDC i have .011'' on the intake. With the 243 heads i can not get past tdc, the valve hits the piston. While doing this i am using light check springs.
I called LG motorsports regarding what my readings and they told me to put number 1 cylinder at tdc and measure the valve drop for the intake and exhaust.
This is what i found
243 head
intake=.202
Exhaust=.219
853 heads
intake=.207
Exhaust=.223
They told me that anything under .200'' will not work.
I am thinking about just buying the AFR 205 with the 64cc chambers. I already have comp 921 springs i can use and 7.4 push rods.
Any opinions on what you are reading?
I also check my degree wheel to make sure it was reading TDC at 0 and its right on.
-
04-28-2011, 02:44 PM #4
What is the installed intake center?
-
04-28-2011, 02:58 PM #5
232-240-600-610 114 LSA=your cam=alot of lift=alot of duration=
some motha fuckin piston to valve action is going on...
A couple options
1. get new pistons with larger valve reliefs
2. get the pistons fly cut
3. get different heads
4. get a smaller cam
also just kind of curious, what is the details of your engine?
-
04-28-2011, 03:12 PM #6
just my 2 cents
Guys on the interenet, and local burger king parking lot will go all day on what you should do. I understand I am in the "guy on the interenet" category. But I recommend you find yourself, a good reliable local machinist with ls experiance.
Reason being-
People can recommend, rotating assemblys, cams, pistons, heads or just what ever all day long. Tell you what works for them, but In the end, your the one spending the money. I along with my other internet buddys, lol have nothing really to loose if YOU get the wrong parts...
but your local machinist has a reputation to uphold... (if he doesn't, don't go to him), so therefore he will make sure your parts properly match up, so that means you will be saving money.
I will gladly give you my experiance and try to help. Nothing is better than face to face though.
-
04-28-2011, 03:56 PM #7
Wow, you are more than close on the intake valves according to LG.
I take it both sets of these heads have been milled extensively??
Edit: I forgot to mention, are you figuring in head gasket thickness? Since you are probably doing as I do,,,and set the heads on without a gasket and a couple of bolts.
If that's the case you need to take the compressed thickness of the head gasket you plan to use and add to those measurements you are getting.Last edited by Firebirdjones; 04-28-2011 at 04:08 PM.
-
04-29-2011, 05:55 AM #8
- Join Date
- Apr 2009
- Location
- Pennsylvania
- Posts
- 285
Pewter- 2000 Camaro SS
I know the 853 heads have not been milled because i just took them off the car and it has never been apart. As for the 243 i dont know because i purchased them from a member off another forum. I have read on forums that you do and dont have to fly cut with the 112 but here is proof. Im sure its ok to run the 853 heads with this cam but its to close for comfort for me. I am going to purchase a set of afr 205 with 62cc.
I was checking with the gasket installed. i measured the gasket and its .062. I just snugged the head bolts down when i put the head on.
-
04-29-2011, 06:11 AM #9
Very good then. I agree, that's too close for comfort. It would take expensive high end valve train, lightweight valves, good springs etc....to control everything. Because the slightest hint of valve float could spell disaster.
Besides,,,I think you'll like the AFR 205's better after it's done
-
04-29-2011, 10:06 AM #10
- Join Date
- Apr 2009
- Location
- Pennsylvania
- Posts
- 285
Pewter- 2000 Camaro SS
-
04-30-2011, 03:29 PM #11
Generally, with stock bottom end/pistons, that grind on a 114LSA will clear and a 112LSA will not.
The BEST bet is to further mill the heads and fly-cut. That's what the fast cars do. The 243s will make the same or very close up top as the AFR 205s. Fly cutting is not the big deal that it's often portrayed as being, and the setups that go that route are consistent performers on the track and the dyno.
-
04-30-2011, 04:33 PM #12
- Join Date
- Apr 2009
- Location
- Pennsylvania
- Posts
- 285
Pewter- 2000 Camaro SS
Thread Information
Users Browsing this Thread
There are currently 1 users browsing this thread. (0 members and 1 guests)
Similar Threads
-
G5X3 114 cam
By barryTA in forum Internal EngineReplies: 2Last Post: 01-26-2008, 06:52 PM -
WTB: G5X3 cam
By chrisLS1SS in forum Parts Wanted / TradeReplies: 12Last Post: 09-05-2007, 03:02 PM -
WTB: G5X3 cam
By chrisLS1SS in forum Parts Wanted / TradeReplies: 0Last Post: 08-30-2007, 05:58 AM -
FS: G5X3 on 112
By happa in forum Parts For Sale / TradeReplies: 1Last Post: 12-17-2006, 05:54 PM -
G5x3 112 NIB
By BlackHawk in forum Parts For Sale / TradeReplies: 8Last Post: 12-28-2005, 06:31 PM
Bookmarks