New To Forum W/90 TPI Mod Questions

[mseven]

I am new to this forum and have read many fine threads and advice in L98 area, great posts guys!
Alright I have a couple questions for some expertise in T.P.I. set-ups.
I am looking at camshafts, LT-4 hot cam in particular with the 113 head ported to bring intake# up to about 195 (or better very little to exhaust) to support the cam additionally to either buy new runners or to get the t.p.i. extrude honed to support this set-up. I want to keep stock exhaust, I have 3:07 gear, 26" tall rears and A-4 trans no mod stock converter. I don not really want to exceed 218 @50 duration (no vacuum issues or cannister) My goal is 100% efficientcy at approx. 350 chp.
1- will this cam grind be effecient for this set up or is there a better choice aside from the L.P.E. 219?
2- Extrussion honning is a little more expensive than bolting on runners (w/ a 40 cfm gain) but what about turbulence through port match, am I better off w/ the honning?
3- In going to 1:6 ratio are the rollers provided in hot cam kit are these rockers narrow bodied I can not seem to get a definitive answer, and are there any geometry or other issues I should be aware off when using the 113 heads? I would apprecciate some advice, as I am getting ready to tear down as early as next week Thanks in advance, Mick

 

[1995 RedVette]

You might want to look up Mad Mic on this forum, he has gotten some very impressive times out of his stock appearing L98. He should have some insight into your parts selection and setup.

Brett

 

[Mad-Mic]

welcome to

i take it your just doing an upper end rebuild?

watch how much you put into your heads for work. there are great heads out there in the 900-1200 range assembled. add roller rockers and be done with them. they will outflow your stock heads out of the box Dport 113's or earlier versions no matter how much work you put into them.

onto the cam......

here are the specs most important what most go by are marked with an x.

Hot Camshaft (P/N 24502586 Specifications IntakeExhaustLobe Lift0.328”0.328” Valve Lift @ 1.5 ratio
@ 1.6 ratio0.492”
0.535”0.492”
0.525”x Duration @0.006 cam lift272°281°@0.050 cam lift210°228°x Lobe Centerline109°115° Lobe Separation112x


it's not that big of a cam. it's noticable over stock and will net more HP gains over stock but from my research on these forums and others have liked more cam after they did the install. something similar to the TPiS ZZ9 cam

ZZ-9 Hydraulic Roller:

Intake Exhaust Advertised duration 282 287
Duration at .050 212 226
Gross lift .483 .520
Lobe separation 112

it's alittle more aggressive on the exhaust side and on 1.6 roller rockers the lift will be about the same as the LT4 hotcam.

difference is in the duration which equals how long the valve stays open. so Time staying open is like running more lift. this is how you sorta cheat when it comes to split duration making the car think it's running more lift.

the ZZ409 is even more aggressive and probably about as much cam as you want in a stock 350 and it should still pass the sniffer with a good tune

any other questions just post away

oh and remember! don't go cheap! buy new lifters and pushrods for safety! nothing like rebuilding a motor and dropping a lifter or bending a pushrod

 

[Edmond]

You have to ditch that stock exhaust. It's very restrictive. I believe that only 1 tail pipe actually flows on the stock mufflers.

With all those mods that you're going to do, I'd say you could gain 40 more with a thorough exhaust system. Meaning headers all the way back to high flow mufflers.

 

[mseven]

welcome to

i take it your just doing an upper end rebuild?

watch how much you put into your heads for work. there are great heads out there in the 900-1200 range assembled. add roller rockers and be done with them. they will outflow your stock heads out of the box Dport 113's or earlier versions no matter how much work you put into them.

onto the cam......

here are the specs most important what most go by are marked with an x.

Hot Camshaft (P/N 24502586 Specifications IntakeExhaustLobe Lift0.328”0.328” Valve Lift @ 1.5 ratio
@ 1.6 ratio0.492”
0.535”0.492”
0.525”x Duration @0.006 cam lift272°281°@0.050 cam lift210°228°x Lobe Centerline109°115° Lobe Separation112x


it's not that big of a cam. it's noticable over stock and will net more HP gains over stock but from my research on these forums and others have liked more cam after they did the install. something similar to the TPiS ZZ9 cam

ZZ-9 Hydraulic Roller:

Intake Exhaust Advertised duration 282 287
Duration at .050 212 226
Gross lift .483 .520
Lobe separation 112

it's alittle more aggressive on the exhaust side and on 1.6 roller rockers the lift will be about the same as the LT4 hotcam.

difference is in the duration which equals how long the valve stays open. so Time staying open is like running more lift. this is how you sorta cheat when it comes to split duration making the car think it's running more lift.

the ZZ409 is even more aggressive and probably about as much cam as you want in a stock 350 and it should still pass the sniffer with a good tune

any other questions just post away

oh and remember! don't go cheap! buy new lifters and pushrods for safety! nothing like rebuilding a motor and dropping a lifter or bending a pushrod

First of all Iwould like to thank everyone who had given me some input.
M. Mik, SORRY I should have been more specific YES upper end rebuild (car has 49000mi. we will see how good it looksonce it is apart). The Hot Cam kit I was refering to was pn#12480002 w/1:6 r.r. (218:i. / 228:e. duration 5:25 lift @50 ) I thought this would make good power and hopefully a reasonably smooth idle Yes I completely agree new pushrods lifters, double roller additionally water pump, hoses, belt (dont want to be back in there any time sooner than neccessary) I really dont need to worry about a sniffer here, however I would like smooth driveability with max effecientcy. and some what quiet hence no 40 flows or l.t.,s.(sorry guys). I am looking at the head options, I have not seen anything in the 900. range everything I see dart-1 , trik flow are approx 1300. Prices so far have been around 900. to full port with 2. 02 new cnc,d polished bowl on my 113s, so if I could do the same w/ a dart1 (no iron) Iwould be interested in new for sure. That seems to be an issue as well. Did you have a take on the T.P.I. MODS. I had mentioned I would like to get your advice there also. Thanks again guys, when I get this project done I will post pics. Mick

 

[Mad-Mic]

First of all Iwould like to thank everyone who had given me some input.
M. Mik, SORRY I should have been more specific YES upper end rebuild (car has 49000mi. we will see how good it looksonce it is apart). The Hot Cam kit I was refering to was pn#12480002 w/1:6 r.r. (218:i. / 228:e. duration 5:25 lift @50 ) I thought this would make good power and hopefully a reasonably smooth idle Yes I completely agree new pushrods lifters, double roller additionally water pump, hoses, belt (dont want to be back in there any time sooner than neccessary) I really dont need to worry about a sniffer here, however I would like smooth driveability with max effecientcy. and some what quiet hence no 40 flows or l.t.,s.(sorry guys). I am looking at the head options, I have not seen anything in the 900. range everything I see dart-1 , trik flow are approx 1300. Prices so far have been around 900. to full port with 2. 02 new cnc,d polished bowl on my 113s, so if I could do the same w/ a dart1 (no iron) Iwould be interested in new for sure. That seems to be an issue as well. Did you have a take on the T.P.I. MODS. I had mentioned I would like to get your advice there also. Thanks again guys, when I get this project done I will post pics. Mick

follow this link. alot of good info in there.

http://www.corvetteactioncenter.com/forums/showthread.php?p=530006#post530006

 

[mjsrun]

Passing emissions can be difficult with diff cam

follow this link. alot of good info in there.

http://www.corvetteactioncenter.com/forums/showthread.php?p=530006#post530006

After 5 years of not passing emissions, finally I had an idea, My mechanic mentioned to me that he gets chips made for various purposes. Well, that is what it took for me to get the correct readings before I finally passed emissions. There is no other route... Change the cam, fail emissions. If you need help contact Howell Engine Development in Marine City, Mi. They will fix you up. May take some tweeking, but the results will be better than the Emissions center telling you to spend $$ before you can get a waiver.
Good luck with your mods
Mjsrun

 

[Moonunit 451]

What's wrong with the 219 cam? It's proven, especially with the A4. The other cams mentioned are most generally used with the higher end R's utilized in standard shift cars. 219 = torque.

And I agree with Edmond, the exhaust needs to go or you're kinda wasting your hard earned cash