TPI, 113 Vette Heads, LT4 Hot Cam...Lengthy
06-10-2003, 06:47 PM
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TPI, 113 Vette Heads, LT4 Hot Cam...Lengthy
Please give me your thoughts...
I bought a set of 10088113 heads (Vette heads 88 and up I believe). They have 3/8" screw in studs and Erson Cams Guideplates. Some porting has been done to the head... Looks like it may have had a 3 angle valve job in the past. 1.94/1.50 valves still fit nicely in the valve seats. One end of the head has 3 accessory holes, the other end has 2.
Additionally, I got all new 1.94/1.50 Manley valves, LT4 valve springs, keepers, valve guide seals, LT4 hot cam, and timing chain.
What I plan to do:
1) Install the Vette heads after clean up porting. Try and go with 1.94/1.50 with a new valve job. Check improvements at track.
2) Install 1.6 roller rockers and check improvements at track.
3) Try different plenum, runner, base configurations to see which works best at this point
4) Change cam to LT4 Hot Cam??? or ??? with stamped steel rockers and check improvements...
5) Install new torque converter and check improvements...
6) add roller rockers and check improvements...
7) open up valve sizes...further port work...and final TPI induction matching to fine tune combination.
8) chip/prom burning to finish off
Basically I am looking for optimum-best performance with the ported TPI parts and Vette heads.
I think the LT4 hot cam can be made to work... with good porting of the aftermarket TPI parts. I don't mind saving some money and selling a couple of things to buy a better cam if necessary. I may need to go with extensive porting (siamesing of Accel intake and runners) and larger valve sizes (2.02/1.6) if I use the LT4 cam.
Should I skip some steps? Avoid the LT4 Hot Cam? What valve sizes should I ultimately use?
I bought a set of 10088113 heads (Vette heads 88 and up I believe). They have 3/8" screw in studs and Erson Cams Guideplates. Some porting has been done to the head... Looks like it may have had a 3 angle valve job in the past. 1.94/1.50 valves still fit nicely in the valve seats. One end of the head has 3 accessory holes, the other end has 2.
Additionally, I got all new 1.94/1.50 Manley valves, LT4 valve springs, keepers, valve guide seals, LT4 hot cam, and timing chain.
What I plan to do:
1) Install the Vette heads after clean up porting. Try and go with 1.94/1.50 with a new valve job. Check improvements at track.
2) Install 1.6 roller rockers and check improvements at track.
3) Try different plenum, runner, base configurations to see which works best at this point
4) Change cam to LT4 Hot Cam??? or ??? with stamped steel rockers and check improvements...
5) Install new torque converter and check improvements...
6) add roller rockers and check improvements...
7) open up valve sizes...further port work...and final TPI induction matching to fine tune combination.
8) chip/prom burning to finish off
Basically I am looking for optimum-best performance with the ported TPI parts and Vette heads.
I think the LT4 hot cam can be made to work... with good porting of the aftermarket TPI parts. I don't mind saving some money and selling a couple of things to buy a better cam if necessary. I may need to go with extensive porting (siamesing of Accel intake and runners) and larger valve sizes (2.02/1.6) if I use the LT4 cam.
Should I skip some steps? Avoid the LT4 Hot Cam? What valve sizes should I ultimately use?
Last edited by smithtc; 11-07-2003 at 09:55 PM.
06-10-2003, 10:51 PM
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it has been done to make the LT4HC work in a TPI enviornment
(extrude honed siamesed runners, mega ported accel manifold,
paper thin plenum) but it was a 6-spd trans.
LT4HC and automatics will need a good torque converter 3500ish
with a 2.0-1.65 str depending on how hooked up the rear is.
a short runner manifold is more complimentry to the cam.
because its power is 2500-6500rpm. so a 3.73/4.11 gear is probably
best. 26-30lb injectors will feed the beast.
ive installed five LT4HC and they all had different characteristics
and the short runner seemed to produce better power through
the 2000-6500rpm range, as a 5/6-spd and 4.11 gears.
airdeano
(extrude honed siamesed runners, mega ported accel manifold,
paper thin plenum) but it was a 6-spd trans.
LT4HC and automatics will need a good torque converter 3500ish
with a 2.0-1.65 str depending on how hooked up the rear is.
a short runner manifold is more complimentry to the cam.
because its power is 2500-6500rpm. so a 3.73/4.11 gear is probably
best. 26-30lb injectors will feed the beast.
ive installed five LT4HC and they all had different characteristics
and the short runner seemed to produce better power through
the 2000-6500rpm range, as a 5/6-spd and 4.11 gears.
airdeano
06-11-2003, 11:25 AM
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Car: 1982 Z28
Engine: LS1
Transmission: T56
My dyno data from when I was running that same setup...aluminum Vette heads no porting or polishing, hogged-out TPI runners and plenum, 52mm throttle body, Accel intake base, HOT cam w/ 1.6 rockers, is at:
http://www.mycar.net/mafb/registry/d...id=963&ref=det
There's more data on various TPI, semi-siamesed, Mini-Ram, Holley Stealth ram from another member at:
http://www.eecis.udel.edu/~davis/z28/winter01/dyno/
http://www.mycar.net/mafb/registry/d...id=963&ref=det
There's more data on various TPI, semi-siamesed, Mini-Ram, Holley Stealth ram from another member at:
http://www.eecis.udel.edu/~davis/z28/winter01/dyno/
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