74, L82 350, changing cam
#41
I agree changing to 1.6 won't be worth it. Your very low rpm engine is not pulling the secondaries even close to open all the way on a 750. Does not matter its feeding it all the air it needs.
Been there done that mistake on making 3310 open mechanicly in 1972 when the 3310 was rated at 780cfm back in 1972. Friend tried it first on his 350 Z/28 then i gave a whirl on the 302 Z/28. They make quicker opening DP carbs with " rear accel pumps " for a reason.
Been there done that mistake on making 3310 open mechanicly in 1972 when the 3310 was rated at 780cfm back in 1972. Friend tried it first on his 350 Z/28 then i gave a whirl on the 302 Z/28. They make quicker opening DP carbs with " rear accel pumps " for a reason.
Last edited by Little Mouse; 04-20-2012 at 06:04 PM.
#42
Safety Car
I agree changing to 1.6 won't be worth it. Your very low rpm engine is not pulling the secondaries even close to open all the way on a 750. Does not matter its feeding it all the air it needs.
Been there done that mistake on making 3310 open mechanicly in 1972 when the 3310 was rated at 780cfm back in 1972. Friend tried it first on his 350 Z/28 then i gave a whirl on the 302 Z/28. They make quicker opening DP carbs with " rear accel pumps " for a reason.
Been there done that mistake on making 3310 open mechanicly in 1972 when the 3310 was rated at 780cfm back in 1972. Friend tried it first on his 350 Z/28 then i gave a whirl on the 302 Z/28. They make quicker opening DP carbs with " rear accel pumps " for a reason.
#43
Thats what im telling you already done it with the screw back in 72 when i was younger and dumber.
I was reading a book by someone smart enough to write a book on holley. One thing he mentions don't do the screw thing. Where the hell were you in 72 lol.
As long as you have a light enough spring on the can it will open plenty fast enough and as far as the little 350 engine and low revs your at will pull it open.
You can pull all kinds of stunts get away with it if you use vacuum. My older cousin put a 950 holley three barrel on his 327/365hp 64 vette.
I was reading a book by someone smart enough to write a book on holley. One thing he mentions don't do the screw thing. Where the hell were you in 72 lol.
As long as you have a light enough spring on the can it will open plenty fast enough and as far as the little 350 engine and low revs your at will pull it open.
You can pull all kinds of stunts get away with it if you use vacuum. My older cousin put a 950 holley three barrel on his 327/365hp 64 vette.
Last edited by Little Mouse; 04-20-2012 at 06:37 PM.
#44
Race Director
1.6 rockers do have their place but this is not it, don't think anyone suggested it. More lift won't help him because the heads won't flow more. More duration won't help him because it is overcammed as it is with his heads and compression. Your cam recommendation has more lift and duration and would be a useless waste of time and money. Best bang for the buck for the OP and you is a new set of good 64CC heads. The 882 heads are crap and severely limit the realized improvement from any other modifications. Heads make power. Flow makes power. Pretty basic.
#45
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Look guys, I didn't mean to start a free for all. Gosh, I just needed a little advise. the story is, We (my husband and I) bought our 74 corvette new in 1974 (yes thats right, we are old). the car has always been in the garage and has 43000 original miles on it. Last summer Joe (my hubby) decided he wanted some more horsepower and wanted to change out old gaskets, put on new shocks and generally bring our vette back to it's original cluster. Our son has taken the tie arms, rods, transmission, and has sand blasted and repainted the parts and frame. It's looking really good. However, Joe is going to put new heads and cams on the engine. (Eldebrocks # 60899 cam and 7102 lifters) is what he is planning on putting on the original -82 engine. The car is a muncie 4 sp. He wants it to add about 110 to 120 more horsepower and keep the idle at 650 to 700 rpms. We wanted all your expert advice on if we are doing the right thing. Thanks to all of your for you help. Sheila
#46
Safety Car
Nicely, I will say I disagree, because with just my current vette is basically a stock engine with a bigger cam and I guarantee my car has more power than stock even with factory heads.
#47
Race Director
#48
Race Director
So your telling 1000s and 1000s of people that taking a stock engine and change out the cam with a high performance one will not make any noticeable or useable power?
Nicely, I will say I disagree, because with just my current vette is basically a stock engine with a bigger cam and I guarantee my car has more power than stock even with factory heads.
Nicely, I will say I disagree, because with just my current vette is basically a stock engine with a bigger cam and I guarantee my car has more power than stock even with factory heads.
#49
Race Director
If you want to add 110-120 HP and maintain good idle you are on the right track.
Go with AFR 64cc 180 heads
http://treperformance.com/i-61882-af...der-heads.html
Felpro 1094 gaskets and a roller cam something like this:
http://www.summitracing.com/parts/HRS-CL110245-12/
This intake.
http://www.summitracing.com/parts/EDL-2101/
Headers.
Performance distributor recurve.
This will get you what you want, maybe a little more.
It is not real cheap but 110 to 120 Hp upgrade while maintaining good idle and vacumn requires good flow without big ports and the 112 LSA roller will give you good vacumn and idle
Go with AFR 64cc 180 heads
http://treperformance.com/i-61882-af...der-heads.html
Felpro 1094 gaskets and a roller cam something like this:
http://www.summitracing.com/parts/HRS-CL110245-12/
This intake.
http://www.summitracing.com/parts/EDL-2101/
Headers.
Performance distributor recurve.
This will get you what you want, maybe a little more.
It is not real cheap but 110 to 120 Hp upgrade while maintaining good idle and vacumn requires good flow without big ports and the 112 LSA roller will give you good vacumn and idle
Look guys, I didn't mean to start a free for all. Gosh, I just needed a little advise. the story is, We (my husband and I) bought our 74 corvette new in 1974 (yes thats right, we are old). the car has always been in the garage and has 43000 original miles on it. Last summer Joe (my hubby) decided he wanted some more horsepower and wanted to change out old gaskets, put on new shocks and generally bring our vette back to it's original cluster. Our son has taken the tie arms, rods, transmission, and has sand blasted and repainted the parts and frame. It's looking really good. However, Joe is going to put new heads and cams on the engine. (Eldebrocks # 60899 cam and 7102 lifters) is what he is planning on putting on the original -82 engine. The car is a muncie 4 sp. He wants it to add about 110 to 120 more horsepower and keep the idle at 650 to 700 rpms. We wanted all your expert advice on if we are doing the right thing. Thanks to all of your for you help. Sheila
Last edited by 63mako; 04-20-2012 at 08:30 PM.
#51
Le Mans Master
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Location: Oxford MA-----You just lost the game!!!!
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Look guys, I didn't mean to start a free for all. Gosh, I just needed a little advise. the story is, We (my husband and I) bought our 74 corvette new in 1974 (yes thats right, we are old). the car has always been in the garage and has 43000 original miles on it. Last summer Joe (my hubby) decided he wanted some more horsepower and wanted to change out old gaskets, put on new shocks and generally bring our vette back to it's original cluster. Our son has taken the tie arms, rods, transmission, and has sand blasted and repainted the parts and frame. It's looking really good. However, Joe is going to put new heads and cams on the engine. (Eldebrocks # 60899 cam and 7102 lifters) is what he is planning on putting on the original -82 engine. The car is a muncie 4 sp. He wants it to add about 110 to 120 more horsepower and keep the idle at 650 to 700 rpms. We wanted all your expert advice on if we are doing the right thing. Thanks to all of your for you help. Sheila
Keep the shiny side up!
Scott
#52
Race Director
If this is the cam your considering it will not idle smooth at 750 RPM. Way too big.
http://www.edelbrock.com/automotive_...7102&submit=go
And I am thinking your looking at this.
http://www.jegs.com/i/Edelbrock/350/2098/10002/-1
The combo I listed will get you what you want. The Edelbrock top end kit has too big of flat tappet cam and the intake won't fit under your hood. The operating range is to 6500 RPM. Your bottom end won't handle that. You will need to address gearing with that much duration. Not a good option. You will also want to change out the timing gears. It has the old nylon gear and it will be either bad or going to be bad once you get it back together with the added stresses a faster ramp cam will load it with.
Edit: I figured your static and dynamic compression with the parts I listed. Your at 10.26 to 1 compression and 8.11 to 1 DCR with an operating range of 1800 to 5400 RPM. This will get you <6000 RPM shift points and decent idle and vacumn. It will outperform the edelbrock package in HP and torque and have way better street manners!
http://www.edelbrock.com/automotive_...7102&submit=go
And I am thinking your looking at this.
http://www.jegs.com/i/Edelbrock/350/2098/10002/-1
The combo I listed will get you what you want. The Edelbrock top end kit has too big of flat tappet cam and the intake won't fit under your hood. The operating range is to 6500 RPM. Your bottom end won't handle that. You will need to address gearing with that much duration. Not a good option. You will also want to change out the timing gears. It has the old nylon gear and it will be either bad or going to be bad once you get it back together with the added stresses a faster ramp cam will load it with.
Edit: I figured your static and dynamic compression with the parts I listed. Your at 10.26 to 1 compression and 8.11 to 1 DCR with an operating range of 1800 to 5400 RPM. This will get you <6000 RPM shift points and decent idle and vacumn. It will outperform the edelbrock package in HP and torque and have way better street manners!
Last edited by 63mako; 04-20-2012 at 11:06 PM.
#53
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St. Jude Donor '05
Look guys, I didn't mean to start a free for all. Gosh, I just needed a little advise.
Page 1 usually get some useful info by p2 its all arguing and d1ckswinging
For some reason the Vette guys love to split hairs and go at it until they throw the mouse across the room. Daily
Listen to 63mako, billa etc. Couple others.
Btw he is right about the secondaries. If the motor doesnt need them open all the way thats all it needed in the first place. Opening them any further wont do jack.
Last edited by cv67; 04-20-2012 at 11:11 PM.
#54
Le Mans Master
Mako's advice, as always is sound - and as he notes with all of those changes combined I think you'll more than hit your goals
I'd offer that with the existing cam, those heads (with all the other changes) would deliver around 375 HP. I couldn't find the cam card (just the base specs) on the Howard's cam, but I'd expect the cam to add another 30+ peak HP...and a good deal more TQ/HP throughout the range. Note that's with 1.6 rockers, and there are other changes required for a retrofit roller cam - so do your homework and set your budget.
I would recommend something a bit less rowdy, but as noted I tend towards the more conservative (read: cheap ) side of the house A set of Vortecs with the existing cam would put you in the 340 HP range at the flywheel, requiring only a head and intake swap. I would tend to keep the existing cam with the Vortecs - it's actually a decent match.
As a baseline, your L82 is probably making around 260 HP now (or less, based on state of tune) and would make around 300 or so with a dual-plane intake and headers/exhaust.
I would add that you should plan for a Q-Jet rebuild and tune to optimize for this new combo, or consider an aftermarket carb. If you plan to leave the car alone after these changes, and you plan to do them all at once, then I'd keep the Q-Jet. If you're planning on making the changes here and there over time, and may make changes later, consider an aftermarket carb. The rationale is that the Q-Jet is the greatest street carb of all time...but there are very few folks that can effectively tune it. Holleys are easy to tune and expertise and parts are readily available. Either way, budget for a dyno tune - without this, you're leaving power on the table for sure.
I'd offer that with the existing cam, those heads (with all the other changes) would deliver around 375 HP. I couldn't find the cam card (just the base specs) on the Howard's cam, but I'd expect the cam to add another 30+ peak HP...and a good deal more TQ/HP throughout the range. Note that's with 1.6 rockers, and there are other changes required for a retrofit roller cam - so do your homework and set your budget.
I would recommend something a bit less rowdy, but as noted I tend towards the more conservative (read: cheap ) side of the house A set of Vortecs with the existing cam would put you in the 340 HP range at the flywheel, requiring only a head and intake swap. I would tend to keep the existing cam with the Vortecs - it's actually a decent match.
As a baseline, your L82 is probably making around 260 HP now (or less, based on state of tune) and would make around 300 or so with a dual-plane intake and headers/exhaust.
I would add that you should plan for a Q-Jet rebuild and tune to optimize for this new combo, or consider an aftermarket carb. If you plan to leave the car alone after these changes, and you plan to do them all at once, then I'd keep the Q-Jet. If you're planning on making the changes here and there over time, and may make changes later, consider an aftermarket carb. The rationale is that the Q-Jet is the greatest street carb of all time...but there are very few folks that can effectively tune it. Holleys are easy to tune and expertise and parts are readily available. Either way, budget for a dyno tune - without this, you're leaving power on the table for sure.
Last edited by billla; 04-21-2012 at 09:29 AM.
#55
Race Director
Mako's advice, as always is sound - and as he notes with all of those changes combined I think you'll more than hit your goals
I'd offer that with the existing cam, those heads (with all the other changes) would deliver around 375 HP. I couldn't find the cam card (just the base specs) on the Howard's cam, but I'd expect the cam to add another 30+ peak HP...and a good deal more TQ/HP throughout the range. Note that's with 1.6 rockers, and there are other changes required for a retrofit roller cam - so do your homework and set your budget.
I would recommend something a bit less rowdy, but as noted I tend towards the more conservative (read: cheap ) side of the house A set of Vortecs with the existing cam would put you in the 340 HP range at the flywheel, requiring only a head and intake swap. I would tend to keep the existing cam with the Vortecs - it's actually a decent match.
As a baseline, your L82 is probably making around 260 HP now (or less, based on state of tune) and would make around 300 or so with a dual-plane intake and headers/exhaust.
I would add that you should plan for a Q-Jet rebuild and tune to optimize for this new combo, or consider an aftermarket carb. If you plan to leave the car alone after these changes, and you plan to do them all at once, then I'd keep the Q-Jet. If you're planning on making the changes here and there over time, and may make changes later, consider an aftermarket carb. The rationale is that the Q-Jet is the greatest street carb of all time...but there are very few folks that can effectively tune it. Holleys are easy to tune and expertise and parts are readily available. Either way, budget for a dyno tune - without this, you're leaving power on the table for sure.
I'd offer that with the existing cam, those heads (with all the other changes) would deliver around 375 HP. I couldn't find the cam card (just the base specs) on the Howard's cam, but I'd expect the cam to add another 30+ peak HP...and a good deal more TQ/HP throughout the range. Note that's with 1.6 rockers, and there are other changes required for a retrofit roller cam - so do your homework and set your budget.
I would recommend something a bit less rowdy, but as noted I tend towards the more conservative (read: cheap ) side of the house A set of Vortecs with the existing cam would put you in the 340 HP range at the flywheel, requiring only a head and intake swap. I would tend to keep the existing cam with the Vortecs - it's actually a decent match.
As a baseline, your L82 is probably making around 260 HP now (or less, based on state of tune) and would make around 300 or so with a dual-plane intake and headers/exhaust.
I would add that you should plan for a Q-Jet rebuild and tune to optimize for this new combo, or consider an aftermarket carb. If you plan to leave the car alone after these changes, and you plan to do them all at once, then I'd keep the Q-Jet. If you're planning on making the changes here and there over time, and may make changes later, consider an aftermarket carb. The rationale is that the Q-Jet is the greatest street carb of all time...but there are very few folks that can effectively tune it. Holleys are easy to tune and expertise and parts are readily available. Either way, budget for a dyno tune - without this, you're leaving power on the table for sure.