T3, PRC 2.5 5.3l's, cometic .040 , should i expect PTV contact
10-19-2007, 07:12 AM
#1
T3, PRC 2.5 5.3l's, cometic .040 , should i expect PTV contact i got my cam in and my heads on. I turned the engine over about 5 times and no contact. Ive also broken it in and driven it several times up to around 6400rpms with no issues. being that im using the thinner headgasket should i expect any issues with PTV contact in the future?
10-19-2007, 10:21 AM
#4
TECH Resident
Join Date: Jan 2003
Location: AUSTIN TX
Posts: 855
Likes: 0
Received 0 Likes
on
0 Posts
I suspect it is pretty close. Did you have the heads milled at all over what TSP normally does just to clean them up. I wish you would have measured it before hand, the p/v clearance on that combo would have been some nice info to know. I am going to run a very similar combo except with a 227 LSK intak lobe, but with a 110 LSA. I SHOULD have a little more clearance on the intake than your setup but i will be checking it anyway. I suspect you may have a problem if you hit the wrong gear or anything like that and mechanically over rev. Are you planning to keep the shift points around 6400 or are you planning to take it a little higher once you are more comfortable with it? Lastly, how does it run, do you have any numbers yet?
10-19-2007, 10:28 AM
#6
TECH Resident
Join Date: Jan 2003
Location: AUSTIN TX
Posts: 855
Likes: 0
Received 0 Likes
on
0 Posts
If those heads came with the platinum dual springs like they should have and they are setup correctly, I suspect it would take more than 7K to cause a problem. At least I hope so. It would be nice to know what kind of clearance he has though.
10-19-2007, 10:34 AM
#7
TECH Apprentice
iTrader: (22)
Join Date: Jun 2006
Location: NM/FL
Posts: 329
Likes: 0
Received 0 Likes
on
0 Posts
from what i remember, the biggest cam you can fit w/out ptv issues is the MS3, i could be wrong. do a search on the 5.3.
on the other hand, TSP sometimes recesses the valves when ordering the ms3 combo, maybe they did it with the T3. you should ask them.
also, as posted, did you mill the heads after you got them from tsp?
finally, one should always check for ptv just to make sure. as an example, i changed cams to a bigger one, and it rotated fine. i must have rotated it 10 times. but, when i checked, i had .050" ptv. too close for comfort. so, i flycut .050. btw, i have the 5.3 stg 2.5, 2.02/1.575 on .040 cometic gaskets, and milled to 59cc.
if i were you, i would contact tsp, if that's who you got the package from, and find out.
hope this helps, and good luck.
on the other hand, TSP sometimes recesses the valves when ordering the ms3 combo, maybe they did it with the T3. you should ask them.
also, as posted, did you mill the heads after you got them from tsp?
finally, one should always check for ptv just to make sure. as an example, i changed cams to a bigger one, and it rotated fine. i must have rotated it 10 times. but, when i checked, i had .050" ptv. too close for comfort. so, i flycut .050. btw, i have the 5.3 stg 2.5, 2.02/1.575 on .040 cometic gaskets, and milled to 59cc.
if i were you, i would contact tsp, if that's who you got the package from, and find out.
hope this helps, and good luck.
Trending Topics
10-19-2007, 10:46 AM
#8
TECH Resident
Join Date: Jan 2003
Location: AUSTIN TX
Posts: 855
Likes: 0
Received 0 Likes
on
0 Posts
from what i remember, the biggest cam you can fit w/out ptv issues is the MS3, i could be wrong. do a search on the 5.3.
on the other hand, TSP sometimes recesses the valves when ordering the ms3 combo, maybe they did it with the T3. you should ask them.
also, as posted, did you mill the heads after you got them from tsp?
finally, one should always check for ptv just to make sure. as an example, i changed cams to a bigger one, and it rotated fine. i must have rotated it 10 times. but, when i checked, i had .050" ptv. too close for comfort. so, i flycut .050. btw, i have the 5.3 stg 2.5, 2.02/1.575 on .040 cometic gaskets, and milled to 59cc.
if i were you, i would contact tsp, if that's who you got the package from, and find out.
hope this helps, and good luck.
on the other hand, TSP sometimes recesses the valves when ordering the ms3 combo, maybe they did it with the T3. you should ask them.
also, as posted, did you mill the heads after you got them from tsp?
finally, one should always check for ptv just to make sure. as an example, i changed cams to a bigger one, and it rotated fine. i must have rotated it 10 times. but, when i checked, i had .050" ptv. too close for comfort. so, i flycut .050. btw, i have the 5.3 stg 2.5, 2.02/1.575 on .040 cometic gaskets, and milled to 59cc.
if i were you, i would contact tsp, if that's who you got the package from, and find out.
hope this helps, and good luck.
10-19-2007, 05:09 PM
#10
I suspect it is pretty close. Did you have the heads milled at all over what TSP normally does just to clean them up. I wish you would have measured it before hand, the p/v clearance on that combo would have been some nice info to know. I am going to run a very similar combo except with a 227 LSK intak lobe, but with a 110 LSA. I SHOULD have a little more clearance on the intake than your setup but i will be checking it anyway. I suspect you may have a problem if you hit the wrong gear or anything like that and mechanically over rev. Are you planning to keep the shift points around 6400 or are you planning to take it a little higher once you are more comfortable with it? Lastly, how does it run, do you have any numbers yet?
10-19-2007, 06:18 PM
#12
On The Tree
Join Date: Oct 2007
Posts: 126
Likes: 0
Received 0 Likes
on
0 Posts
i setup one small block with 27thou piston to head + up to 9000 rpms no worrys
when the heads were removed the flycut areas were shiny like the valve gave the pistons a massage(soo close!)there was nothing wrong with that engine but the owner freaked out. i guess i can confidently say don't run any more than 30thou piston to head.
when the heads were removed the flycut areas were shiny like the valve gave the pistons a massage(soo close!)there was nothing wrong with that engine but the owner freaked out. i guess i can confidently say don't run any more than 30thou piston to head.
10-19-2007, 07:00 PM
#13
TECH Fanatic
iTrader: (10)
Join Date: Aug 2004
Location: Rochester,Ny
Posts: 1,433
Likes: 0
Received 0 Likes
on
0 Posts
i think you may be asking for trouble.It is probably really damn close and in my opinion it should have been checked without a doubt.Not checking because the guys at tsp didnt mention flycutting is just not smart in my opinion..You may end up being alright but I know with a torquer 2 and a cometic .040 with those heads is going to be really on the line close.With the T3 and the more aggresive ramp rates it is just asking for trouble..DONT miss a single shift and you may get by.
10-20-2007, 10:53 AM
#14
i think you may be asking for trouble.It is probably really damn close and in my opinion it should have been checked without a doubt.Not checking because the guys at tsp didnt mention flycutting is just not smart in my opinion..You may end up being alright but I know with a torquer 2 and a cometic .040 with those heads is going to be really on the line close.With the T3 and the more aggresive ramp rates it is just asking for trouble..DONT miss a single shift and you may get by.
10-20-2007, 02:43 PM
#16
TECH Fanatic
iTrader: (10)
Join Date: Aug 2004
Location: Rochester,Ny
Posts: 1,433
Likes: 0
Received 0 Likes
on
0 Posts
what i would do is pull and valve cover and put a couple checker springs on one cylinder and turn the motor over by hand,And as you rotate the motor push the valves down and put a dial indicator on it to see how much clearance you have..You need .080 on the intake and .110 on the exhaust.
10-20-2007, 04:23 PM
#17
On The Tree
iTrader: (9)
Join Date: Apr 2007
Location: Tulsa, OK
Posts: 110
Likes: 0
Received 0 Likes
on
0 Posts
what i would do is pull and valve cover and put a couple checker springs on one cylinder and turn the motor over by hand,And as you rotate the motor push the valves down and put a dial indicator on it to see how much clearance you have..You need .080 on the intake and .110 on the exhaust.
best response yet.
my solution was to tear it down and clay ti, but thats alot of work.
10-21-2007, 02:17 AM
#18
TECH Resident
Join Date: Jan 2003
Location: AUSTIN TX
Posts: 855
Likes: 0
Received 0 Likes
on
0 Posts
i setup one small block with 27thou piston to head + up to 9000 rpms no worrys
when the heads were removed the flycut areas were shiny like the valve gave the pistons a massage(soo close!)there was nothing wrong with that engine but the owner freaked out. i guess i can confidently say don't run any more than 30thou piston to head.
when the heads were removed the flycut areas were shiny like the valve gave the pistons a massage(soo close!)there was nothing wrong with that engine but the owner freaked out. i guess i can confidently say don't run any more than 30thou piston to head.