LT1-LT4 Modifications 1993-97 Gen II Small Block V8

LT1 heads w/ 2.02 and 1.60 valves

Old 04-19-2011, 03:16 PM
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Default LT1 heads w/ 2.02 and 1.60 valves

Anyone running this set up? Any problems?

Al 95 Z28
Old 04-19-2011, 04:15 PM
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Your question is so open-ended it's not funny. You're going to have to be FAR more specific.

Most of the time there is no benefit to going with larger valves.
Old 04-19-2011, 04:38 PM
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I had 1.56 and 2.0 valves in my LE2 heads
I have 1.6 and 2.055 valves in my LE-ported Dart heads. (which is about as big as you can get with stock geometry)

Based on the information provided in your other thread (unported heads, questionable VJ, no bowl work, larger valves),
my advice is to take (or send) them to a reputable shop for porting and a proper VJ if you want to make them useful.
Otherwise, run stock heads with stock valves.

Larger curtain areas without the port work to back it up won't help, in fact it will probably hurt.
Old 04-19-2011, 05:58 PM
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Problem is I bought the car with this set up. No idea who did it or if they had any idea what they were doing. it has Manley valves and they opened up the ports some. Some grinding under the valves. Have no idea what it looked like before of if they helped or hurt things. What I do know is the exhaust valve is hitting the seat right at the inner edge of the valve. The tops of the valves are scarred up, looks like someone squeezed them with a pliers or vice grip? had to file the crap out of them to get them out of the guides without damaging them.

What I was after is if this valve and seat combination actually works.

Have many other problems I'm trying to solve at the same time, like the rockers are hitting the retainers and the hex on the stud. When I get past the valves I'll try to deal with push rod length and so on. Checked the valve spring pressure, on the seat 110 pounds. Not enough for the cam that was in it.

This car has been a real learning experience.

Thanks,

Al
Old 04-19-2011, 06:16 PM
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Originally Posted by Big Al
Anyone running this set up? Any problems?

Al 95 Z28
Originally Posted by Big Al
What I was after is if this valve and seat combination actually works.

Thanks,

Al
well "work", yes. I have 2.02/1.60 valves in my "ported" AL heads. have had them on for years.

sounds like your heads were not set up right for that size valve.
Old 04-19-2011, 07:15 PM
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Originally Posted by ******
well "work", yes. I have 2.02/1.60 valves in my "ported" AL heads. have had them on for years.

sounds like your heads were not set up right for that size valve.
What are you basing your statement that it "works" on? Physically fit if halfassed yes, actually worthwhile performance wise I have yet to see a case to back that up.

To PROPERLY get valves that big in you need new seats which is wasted money when 2.00/1.56 valves fit the stock seats and have been in the 9s NA in well ported GM LT1 castings.

110lbs on the seat is not enough spring for a cam that might be big enough to support a 350 that would benefit from a valve that big, so chances are real good your heads were halfassed. Question is how will you deal with it?
Old 04-19-2011, 08:10 PM
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Originally Posted by 96capricemgr
What are you basing your statement that it "works" on? Physically fit if halfassed yes, actually worthwhile performance wise I have yet to see a case to back that up.

To PROPERLY get valves that big in you need new seats which is wasted money when 2.00/1.56 valves fit the stock seats and have been in the 9s NA in well ported GM LT1 castings.

110lbs on the seat is not enough spring for a cam that might be big enough to support a 350 that would benefit from a valve that big, so chances are real good your heads were halfassed. Question is how will you deal with it?
Took the heads to a local shop this afternoon. We cleaned up two combustion chambers and measured everything. The stock exhaust valve seat is too small for 1.6" valves. They opened it up so much stock valves won't work. So the correct way to fix it is to put in 1.625" exhaust seats. But it's not worth doing. So he's going to clean up the valves and see what he can do with the stock seat. Another cluster

They guy is very good but not what you would call a hot rod head guy. But, I'm confident he'll figure out something.

Have a plethora of other things to deal with. Camshaft, push rods, springs, cylinders, tuning, and the beat goes on...

Al
Old 04-19-2011, 08:39 PM
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Before throwing more good money after bad have you considered getting good stock heads and using those?

I realize you might not have the budget to have stock heads ported properly at this time.

Glad your guy confirmed what I said about 1.6 valves not working right in a stock seat, otherwise a few of the usual suspects would have told you otherwise just to contradict me.
Old 04-19-2011, 09:20 PM
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more than capable of running big valves with the correct seats and machine work.........im running 2.08's and 1.60's in a trick flow casting along with alot of other people with no issues.....
Old 04-19-2011, 09:22 PM
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I second about getting the stockers....you can always get the le1/le2 ported later on....i did a lot of calling when i got my heads done and before i scored a deal on a used set of LE2 heads there was pretty much no body that can beat the price and flow numbers of Loyd Elliott.
Old 04-19-2011, 09:24 PM
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Originally Posted by quik95lt1
more than capable of running big valves with the correct seats and machine work.........im running 2.08's and 1.60's in a trick flow casting along with alot of other people with no issues.....
i thought the question was on the lt1 stock casting not trickflow,dart,or afr etc.....and not that it will work but will they make the lt1 casting flow more.
Old 04-19-2011, 10:22 PM
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Originally Posted by 96capricemgr
have you considered getting good stock heads and using those?
Exactly ... you could pick up a set of used stock heads for under $200.
Have the local shop clean em up and make sure they're not warped ($50?)
They'll work, have the correct springs and you'll know what pushrods you
need.
Old 04-20-2011, 12:46 AM
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[QUOTE=96capricemgr;14806080]What are you basing your statement that it "works" on?

To PROPERLY get valves that big in you need new seats which is wasted QUOTE]

Dwayne:

The OP asked: LT1 heads w/ 2.02 and 1.60 valves

--------------------------------------------------------------------------------
Anyone running this set up? Any problems?

Al 95 Z28

In '03 RacePrep ported my AL heads and did install larger seats for the 2.02/1.60 Ferra valves. Hardened exhaust seats.


Didn't say they were the best but they have worked well on my 350 and 383.
Old 04-20-2011, 01:52 AM
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Had some in my 643s, no issues at all with PTV clearance
Old 04-20-2011, 04:53 AM
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[quote=******;14807537]
Originally Posted by 96capricemgr
What are you basing your statement that it "works" on?

To PROPERLY get valves that big in you need new seats which is wasted QUOTE]

Dwayne:

The OP asked: LT1 heads w/ 2.02 and 1.60 valves

--------------------------------------------------------------------------------
Anyone running this set up? Any problems?

Al 95 Z28

In '03 RacePrep ported my AL heads and did install larger seats for the 2.02/1.60 Ferra valves. Hardened exhaust seats.


Didn't say they were the best but they have worked well on my 350 and 383.

Please deine "worked well.
Old 04-20-2011, 05:45 AM
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trust me, nothing race prep ever touched did well. IIRC they did a H/C LS1 that made 370rwhp with a set of their heads
Old 04-20-2011, 08:51 AM
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i have 2.08/1.6's in my lt4 heads. and they work well..
Old 04-20-2011, 01:33 PM
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[QUOTE=96capricemgr;14807824]
Originally Posted by ******


Please deine "worked well.
well Dwayne the RacePrep heads made 350HP/351TQ at the wheels on a stock bottom end 350, edelbrock shorty header, 52 mm bored stock TB, 30 lb SVO injector motor with a custom grind COMP mild 214/220 @ 112 cam. Tad (ProTools) did the dyno pulls. These heads are over 9 years old now and on my 383. Both motors pass California smog test which for me is a barrier I need to adhere to on any mod.

Again not saying they are the "best" in terms of MAX performance but were assembled well and do have larger seats. They flow Int: .600 lift @ 280.8; Int .600 lift @ 175.8. This was a budget port job for $650 back then + the parts.

Since then companies like AI and LE have developed head and cam combos that do have great "performance" results using smaller valves.

Originally Posted by Wicked94Z
trust me, nothing race prep ever touched did well. IIRC they did a H/C LS1 that made 370rwhp with a set of their heads
Wicked

I don't know the details on the RacePrep LS motor you mentioned. My only dealing with them was a simple head/cam combo back in early 03 which for me worked well.

They went out of biz years ago. The partners (Joe & Brian) split because Brian took a job working for his father in law in real estate and Joe moved next door to another shop.


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