Will a 490 lift cam fit without interferance in TPI heads?
#1
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Car: 2KGTP
Engine: supercharged 3800 L67
Transmission: 4T65E
Axle/Gears: 2.93
Will a 490 lift cam fit without interferance in TPI heads?
I plan on installing a comp cams 274XE. The lift figures are .487"/.490". I have the cast iron center bolt TPI heads. I will change the valve springs with the comp cams 981's. I'm more concerned with retainer to seal clearance.
While we're on the subject I might as well ask if I will have any valve to piston clearance problems?
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1986 CAMARO Z28 ->
151,000 original miles, 43,000 on 89' vette 350 block, Holley 650 DP, Weiand intake, 1.6 rockers, 1 5/8" headers, no cat, 2 1/2" Flowmaster catback, Mallory coil, March pulleys, B&M Ripper shifter, T5 with 3.35 1st gear and 0 miles, 90% Centerforce clutch, 3.73 posi, Eibach 1" drop springs, Spohn LCA's, Spohn adjustable panhard rod, Subframe connectors, all bushings are urethane, 2 12" Sound Streams, 2 Infinity 6X9's, 2 Pioneer 6X9's, 800 watt Lanzar Vibe amp. ET 13.32@ 106.4MPH 3300lbs less driver and speakers Next mods-> Extreme Energy 268 cam, Holley street dom intake, ported heads.
1987 TRANS AM ->
73,000 miles, 305TPI, auto, gutted air box, gutted cat.
While we're on the subject I might as well ask if I will have any valve to piston clearance problems?
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1986 CAMARO Z28 ->
151,000 original miles, 43,000 on 89' vette 350 block, Holley 650 DP, Weiand intake, 1.6 rockers, 1 5/8" headers, no cat, 2 1/2" Flowmaster catback, Mallory coil, March pulleys, B&M Ripper shifter, T5 with 3.35 1st gear and 0 miles, 90% Centerforce clutch, 3.73 posi, Eibach 1" drop springs, Spohn LCA's, Spohn adjustable panhard rod, Subframe connectors, all bushings are urethane, 2 12" Sound Streams, 2 Infinity 6X9's, 2 Pioneer 6X9's, 800 watt Lanzar Vibe amp. ET 13.32@ 106.4MPH 3300lbs less driver and speakers Next mods-> Extreme Energy 268 cam, Holley street dom intake, ported heads.
1987 TRANS AM ->
73,000 miles, 305TPI, auto, gutted air box, gutted cat.
#2
Now I am not going to say that that could be a problem running, but if you have a standard
flat top piston (especially with no valve reliefs) you could be get into big problems.
As well you could used a thicker head gasket?
Most builders use a generic head gasket that is 40 thousandth's of an inch. If you experience valve to piston clearence problems you could go to a copper gasket. They are 20 thousandth's of an inch thicker yet.
Your springs I am sure you know can not be too strong or weak. You could use a stock spring but if you hit 4500 RPM - 5000 RPM you would smash that spring together so hard something would break. Probably a spring of about 100 lbs. with an internal dampener would be fabulous. Hopes that helps.
flat top piston (especially with no valve reliefs) you could be get into big problems.
As well you could used a thicker head gasket?
Most builders use a generic head gasket that is 40 thousandth's of an inch. If you experience valve to piston clearence problems you could go to a copper gasket. They are 20 thousandth's of an inch thicker yet.
Your springs I am sure you know can not be too strong or weak. You could use a stock spring but if you hit 4500 RPM - 5000 RPM you would smash that spring together so hard something would break. Probably a spring of about 100 lbs. with an internal dampener would be fabulous. Hopes that helps.
#3
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Location: Michigan, Novi
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Car: 2KGTP
Engine: supercharged 3800 L67
Transmission: 4T65E
Axle/Gears: 2.93
To give you a better idea. The engine I have is an 89' vette 350 block with roller cam and 4 bolt main. I think I might be ok with piston to valve, I was going to have the heads milled a bit too.
My friend works at a machine shop and I could have him machine them down so I don't have interferance with the valve guides and retainers.
Anybody else done this kind of cam swap? PLEASE HELP. I only have about 2 weeks.
------------------
1986 CAMARO Z28 ->
151,000 original miles, 43,000 on 89' vette 350 block, Holley 650 DP, Weiand intake, 1.6 rockers, 1 5/8" headers, no cat, 2 1/2" Flowmaster catback, Mallory coil, March pulleys, B&M Ripper shifter, T5 with 3.35 1st gear and 0 miles, 90% Centerforce clutch, 3.73 posi, Eibach 1" drop springs, Spohn LCA's, Spohn adjustable panhard rod, Subframe connectors, all bushings are urethane, 2 12" Sound Streams, 2 Infinity 6X9's, 2 Pioneer 6X9's, 800 watt Lanzar Vibe amp. ET 13.32@ 106.4MPH 3300lbs less driver and speakers Next mods-> Extreme Energy 268 cam, Holley street dom intake, ported heads.
1987 TRANS AM ->
73,000 miles, 305TPI, auto, gutted air box, gutted cat.
My friend works at a machine shop and I could have him machine them down so I don't have interferance with the valve guides and retainers.
Anybody else done this kind of cam swap? PLEASE HELP. I only have about 2 weeks.
------------------
1986 CAMARO Z28 ->
151,000 original miles, 43,000 on 89' vette 350 block, Holley 650 DP, Weiand intake, 1.6 rockers, 1 5/8" headers, no cat, 2 1/2" Flowmaster catback, Mallory coil, March pulleys, B&M Ripper shifter, T5 with 3.35 1st gear and 0 miles, 90% Centerforce clutch, 3.73 posi, Eibach 1" drop springs, Spohn LCA's, Spohn adjustable panhard rod, Subframe connectors, all bushings are urethane, 2 12" Sound Streams, 2 Infinity 6X9's, 2 Pioneer 6X9's, 800 watt Lanzar Vibe amp. ET 13.32@ 106.4MPH 3300lbs less driver and speakers Next mods-> Extreme Energy 268 cam, Holley street dom intake, ported heads.
1987 TRANS AM ->
73,000 miles, 305TPI, auto, gutted air box, gutted cat.
#5
Member
im running a .555 lift cam with 1.6 rockes (total valve lift of .888),.275 dome pistons and .040 copper head gaskets with no valve clearance problems.
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85 IROC 350 11:1keith blacks,.555lift erson roller cam,1.5 crane roller rockers,edelbrock intake,holley 4150 750dbl pumper, nitrous oxide,full length heddman headers,true dual exhaust, 11"stall converter, 700R4, 3.73 locker
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85 IROC 350 11:1keith blacks,.555lift erson roller cam,1.5 crane roller rockers,edelbrock intake,holley 4150 750dbl pumper, nitrous oxide,full length heddman headers,true dual exhaust, 11"stall converter, 700R4, 3.73 locker
#6
TGO Supporter
i check valve to piston clearance without head gasket (.040 usually) and you'd have to have about .650 lift before you start to get to the .100 minumin,(w/flat tops w/valve reliefs) most of the time. the only true way to know about the retainer to guide clearance is to check it for sure. if i were to take a guess i'd say you'll be fine.
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ICON Motorsports
1st & 3rd
MM Black Diamond 538 F&AM
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ICON Motorsports
1st & 3rd
MM Black Diamond 538 F&AM
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