Need advice for my first engine upgrade
Burning Brakes
Joined: May 2009
Posts: 1,232
Likes: 6
From: Tucson AZ
St. Jude Donor '12
Just adjust the length until the contact area on the valve is correct as the valve opens and closes. I use a sharpie to blacken the top of the valve stem, then after a few open/close cycles, the ink will be rubbed off a bit where the valve is contacting the rocker over it's travel.
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
The machine shop I use made one for me in about 5 minutes. Basically took a stock pushrod and cut it in half, took about 1/4" off the middle. Then they threaded the inside of each piece, ran a threaded rod down in one side with a little red locktite, leaving about an inch and a half of threads exposed. Other side was threaded onto that and that's what I used to help determine what length push rods to get.
Just adjust the length until the contact area on the valve is correct as the valve opens and closes. I use a sharpie to blacken the top of the valve stem, then after a few open/close cycles, the ink will be rubbed off a bit where the valve is contacting the rocker over it's travel.
Just adjust the length until the contact area on the valve is correct as the valve opens and closes. I use a sharpie to blacken the top of the valve stem, then after a few open/close cycles, the ink will be rubbed off a bit where the valve is contacting the rocker over it's travel.
The CompCams read directly off a vernier scale and cost about $30.
Heel & Toe
Joined: Dec 2008
Posts: 15
Likes: 0
From: Katy Texas
Up Grades
Mike, I also did a 383 (.60) ,Scat crank set up similar to yours. 2 issues, 1 - The newer Holly carbs floats and meter blocks have problems with ethanol fuels,they flake and clog,making the carb flood. 2 - Flat tappet cams DO NOT LIKE synthetic oils,Rollers are ok. . Lost my cam and crank before 3000 miles. (the Dyno was at 525 RWHP). If you are looking for a nice top in, high torque set up call Summit racing for a pkg. deal .I got heads 72cc ,202/164 dual spring heads with a nice Edelbrocl carb and intake for aroung 1500.00. Got the poished intake and ported it to 300cfm for the flow. You have to releave sinus congestion-lol
Useds a flat tappet cam 492 lift and it was a screaming banshee.( tore up 2 trans and the rear after) There are a number of ways to improve your powerplant, but what ever you have ,you will have to beef up trans,rear end, and suspension to handle the torque. Expect to pop aroung 5000 - 10,000 for all of this . I did and I did alot of the work myself. Good Luck
Useds a flat tappet cam 492 lift and it was a screaming banshee.( tore up 2 trans and the rear after) There are a number of ways to improve your powerplant, but what ever you have ,you will have to beef up trans,rear end, and suspension to handle the torque. Expect to pop aroung 5000 - 10,000 for all of this . I did and I did alot of the work myself. Good Luck
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
Thread Starter
Racer
Joined: Oct 2011
Posts: 318
Likes: 3
From: NP Nebraska
Mike, I also did a 383 (.60) ,Scat crank set up similar to yours. 2 issues, 1 - The newer Holly carbs floats and meter blocks have problems with ethanol fuels,they flake and clog,making the carb flood. 2 - Flat tappet cams DO NOT LIKE synthetic oils,Rollers are ok. . Lost my cam and crank before 3000 miles. (the Dyno was at 525 RWHP).
Useds a flat tappet cam 492 lift and it was a screaming banshee.( tore up 2 trans and the rear after) There are a number of ways to improve your powerplant, but what ever you have ,you will have to beef up trans,rear end, and suspension to handle the torque. Expect to pop aroung 5000 - 10,000 for all of this . I did and I did alot of the work myself. Good Luck
Useds a flat tappet cam 492 lift and it was a screaming banshee.( tore up 2 trans and the rear after) There are a number of ways to improve your powerplant, but what ever you have ,you will have to beef up trans,rear end, and suspension to handle the torque. Expect to pop aroung 5000 - 10,000 for all of this . I did and I did alot of the work myself. Good Luck
I have the stock Vortec heads and planned to put them on stock but after hearing from billla, I am considering one of the solutions to give a bit more lift clearance. I have a cam with 0.458 lift and even with 1:51 arms I guess I can have spring problems as GMPP allows 0.475 for the heads, everyone else cautions to look for as little as 0.450 off the factory line for these heads.
A few more questions just to ease my curiosity and keep me from doing something stupid:
Can I use the stock 350 pushrods for the new valve train if I will check for a good tracing? I am tempted to try unless someone points out why it will obviously not work - then I won't bother.
How likely am I to have problems reusing the bolts from the old heads and intake manifold if I clean them well?
Last edited by myko; Nov 14, 2011 at 04:26 PM.
Thread Starter
Racer
Joined: Oct 2011
Posts: 318
Likes: 3
From: NP Nebraska
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
You can use the stock pushrods if they end up being the right length, which may be the case.
I would buy new head bolts - the GMPP set is like $30, and they already have sealant on them.
I would buy new head bolts - the GMPP set is like $30, and they already have sealant on them.
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
To be clear, my advise was to use a cam with less lift. Since you want to stick with your selected cam -I offered suggestions on how to make it work. You're for sure in the zone where you *may* - not *will* but *may* have retainer-to-seal issues. No way to tell until it's mocked-up and checked.
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Thread Starter
Racer
Joined: Oct 2011
Posts: 318
Likes: 3
From: NP Nebraska
To be clear, my advise was to use a cam with less lift. Since you want to stick with your selected cam -I offered suggestions on how to make it work. You're for sure in the zone where you *may* - not *will* but *may* have retainer-to-seal issues. No way to tell until it's mocked-up and checked.
Thread Starter
Racer
Joined: Oct 2011
Posts: 318
Likes: 3
From: NP Nebraska
Sadly, I almost need a reserve bank account to bail me out when my pride starts running up a tab
Any advice on how to put on the balancer without buying the tool or injuring the seal in the timing chain cover?
Any advice on how to put on the balancer without buying the tool or injuring the seal in the timing chain cover?
Heel & Toe
Joined: Dec 2008
Posts: 15
Likes: 0
From: Katy Texas
I am in full agreement, However after using Joe Gibbs break in oil (Engine builder DID NOT give Comp cam build documentation or recommend additive, I lost the cam lobes and twisted the crank in half. It made for quite a mess. And expensive lesson to be sure.
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
Most parts places rent the balancer tool - and just make sure the balancer sleeve is wet with ***'y lube or oil before installation.
Thread Starter
Racer
Joined: Oct 2011
Posts: 318
Likes: 3
From: NP Nebraska
I have the heads, pan, balancer on. I have the lifters and rods in place. Just need to set the valves, put the water pump on, fill with break-in oil and install!
When setting valve lash I have heard a number of different opinions and advice. The most common advice is to tighten to zero lash and then 1/2 a turn tighter while the lifter is on the base circle of the cam.
The best way be sure you are completely off the lobes as you adjust lash is where I am concerned. I have seen a number of ways but I want to be sure and do it without turning the engine over 32 times.
Method A: Adjust the exhaust as the intake is just starting to open then adjust the intake as the exhaust starts to close.
Method B: Adjust both intake and exhaust for #1 when at TDC. Turn balancer 90 degrees and adjust #8. Continue through the firing order with 90 turns between each.
Which way is better?
When adjusting for zero lash on hydraulic lifters do you just wiggle the pushrods while tightening until they don't have any free movement or do you wiggle the rocker arm to assure that there is no space b/t it and the valvestem?
Thanks,
Mike
When setting valve lash I have heard a number of different opinions and advice. The most common advice is to tighten to zero lash and then 1/2 a turn tighter while the lifter is on the base circle of the cam.
The best way be sure you are completely off the lobes as you adjust lash is where I am concerned. I have seen a number of ways but I want to be sure and do it without turning the engine over 32 times.
Method A: Adjust the exhaust as the intake is just starting to open then adjust the intake as the exhaust starts to close.
Method B: Adjust both intake and exhaust for #1 when at TDC. Turn balancer 90 degrees and adjust #8. Continue through the firing order with 90 turns between each.
Which way is better?
When adjusting for zero lash on hydraulic lifters do you just wiggle the pushrods while tightening until they don't have any free movement or do you wiggle the rocker arm to assure that there is no space b/t it and the valvestem?
Thanks,
Mike
Last edited by myko; Nov 16, 2011 at 06:25 PM.
Thread Starter
Racer
Joined: Oct 2011
Posts: 318
Likes: 3
From: NP Nebraska
On to something new.
I am looking my old dizzy over before I just throw it back in. It worked when I took it off so I was surprised when I looked it up and it is the original Delco GM1103353 part. The springs are old and could have been silver or could have been black. Regardless, I was planning to change them. The wires and plastic parts are getting brittle. I had already changed the cap and rotor but I wonder how much a new part will affect function? I had always though of a distributor as something that only needs replaced if it was broken.
Should I get a new spring set and possibly an adjustable vacuum advance or should I just get a dizzy? If I get a new one what kind, coil, and gear material would you recommend?
I am looking my old dizzy over before I just throw it back in. It worked when I took it off so I was surprised when I looked it up and it is the original Delco GM1103353 part. The springs are old and could have been silver or could have been black. Regardless, I was planning to change them. The wires and plastic parts are getting brittle. I had already changed the cap and rotor but I wonder how much a new part will affect function? I had always though of a distributor as something that only needs replaced if it was broken.
Should I get a new spring set and possibly an adjustable vacuum advance or should I just get a dizzy? If I get a new one what kind, coil, and gear material would you recommend?
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
Mike, I'll get you an answer to your valve adjustment question - I'm working on a valve FAQ today and should have posted this weekend. Until then, here's a good article on the method I use: http://www.carcraft.com/howto/ccrp_0...aft/index.html. Key point is accurating locating zero lash...and if you haven't done that before getting some assistance from someone really helps.
Distributors get worn out like anything else. You can rebuild that one...but honestly I'd pop for a new one if it's in the budget. If you're willing and originality isn't a factor, swapping over to HEI is generally the best investment. If that's interesting I can provide more background, or there might be a FAQ here for the swap. It's a bit more work and expense (the wires will need to be swapped too) but it's trouble-free once it's in.
Distributors get worn out like anything else. You can rebuild that one...but honestly I'd pop for a new one if it's in the budget. If you're willing and originality isn't a factor, swapping over to HEI is generally the best investment. If that's interesting I can provide more background, or there might be a FAQ here for the swap. It's a bit more work and expense (the wires will need to be swapped too) but it's trouble-free once it's in.
Heel & Toe
Joined: Dec 2008
Posts: 15
Likes: 0
From: Katy Texas
Mike, when I up graded my engine I choose a billet MSD "dizzy". Remember that the '74 was the last year for points ('75 converted to HEI with eletronic tach) with a cable drive to the tach. Changing to a MSD with new coil and internals are relatively simple (Had to locate a tach drive shaft). I have the added benefit of 50k over 30k floating point systems that my engine requires. Taking care of the spark situation now will eliminate any possible problems down the road.
Thread Starter
Racer
Joined: Oct 2011
Posts: 318
Likes: 3
From: NP Nebraska
Distributors get worn out like anything else. You can rebuild that one...but honestly I'd pop for a new one if it's in the budget. If you're willing and originality isn't a factor, swapping over to HEI is generally the best investment. If that's interesting I can provide more background, or there might be a FAQ here for the swap. It's a bit more work and expense (the wires will need to be swapped too) but it's trouble-free once it's in.
There is one for $60 with a 48K coil (http://www.cfrperformance.com/CHEVY_...-d6001-pbk.htm)
Then you can find Mallory and MSD units for over $200. Most have 60-65K coils. How much spark can I really need (I doubt I ever have this car near 7000 RPM)?
Thread Starter
Racer
Joined: Oct 2011
Posts: 318
Likes: 3
From: NP Nebraska
Mike, when I up graded my engine I choose a billet MSD "dizzy". Remember that the '74 was the last year for points ('75 converted to HEI with eletronic tach) with a cable drive to the tach. Changing to a MSD with new coil and internals are relatively simple (Had to locate a tach drive shaft). I have the added benefit of 50k over 30k floating point systems that my engine requires. Taking care of the spark situation now will eliminate any possible problems down the road.
I have read that the only advantage of choosing a billet dizzy would be improved looks. Would you agree or have you noticed a measured improvement in function with the higher quality part?
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
With an '80, I expect you've already got HEI (?)
You absolutely don't need anything crazy - a stock GM replacement would be fine; a bit more money spent on the MSD Street Fire is money well spent as it comes with a tuning kit and an adjustable vacuum can...which makes tuning after installation a breeze
http://www.msdignition.com/Products/...stributor.aspx
You absolutely don't need anything crazy - a stock GM replacement would be fine; a bit more money spent on the MSD Street Fire is money well spent as it comes with a tuning kit and an adjustable vacuum can...which makes tuning after installation a breeze
http://www.msdignition.com/Products/...stributor.aspx