sos-ddClassicRob wrote: ↑Tue Jul 06, 2021 8:58 amGive me a god damn break! I dont want to talk about my moms dementia! I come here to get in a better mood. Dads still alive and this has been going on for 10 years. The house, funeral, nurse, etc. is already bought and paid for. This isnt anything new. The car I am modifying is the same car I have memories of when I was a kid. The one she used to drive! Im trying to get it running good, so can we move on??rebelyell wrote: ↑Mon Jul 05, 2021 10:47 pm Sorry 'bout your mom. Already been through the dementia & it's subsequent end result. Perhaps you already know this, but if not; a passing and the period following it often reveals some financial surprise(s). In time, your family's position may become improved or even degraded. Also, emotions / visions/ spirituality tend to change in time; sometimes in unpredictable ways too. If your loved one's estate is subject to probate; many of its assets may be frozen while ample time is afforded for any claims / liabilities (assets as well) to be brought to light. Prepare yourselves for unforetold change.
Suggest primary focus remain on mom's care & aftercare; while putting the toys on hold until some 12-18 months after her passing.
Smog Era 350 Vortec build.
Moderator: Team
Re: Smog Era 350 Vortec build.
Re: Smog Era 350 Vortec build.
The cam is from Comp, X4254H, installed 4 degrees advanced. If you want the dcr, you will have to do the math.skinny z wrote: ↑Wed Jul 07, 2021 1:46 pmHave you calculated what the DCR is for that combination? While DCR is dissed by many, I find that for a given format, such as a Vortec headed 350, it has some value. That you run on regular grade fuel is something that's come up in another thread and the running compression was a question of note.rfoll wrote: ↑Wed Jul 07, 2021 11:10 am One of the benefits of the Vortec head is the excellent swirl characteristics. I would think it would reduce the need for a really tight quench. If you are going to deck the block anyway, the increase in compression is worth the effort. I have a flat top 350 with Vortec heads in my car now. piston is .025" in the hole with the .028" gasket. Static compression is 9.63. My cam is 10 degrees less than your xe 262. It runs very good on regular fuel and I have never heard it ping.
So much to do, so little time...
Re: Smog Era 350 Vortec build.
The math says 8.3:1 (give or take).
Many have said that's very workable as you have.
I found that it didn't take too kindly to aggressive timing. I also had issues with part throttle cruise. But then again I was trying to squeeze more MPG and timing was approaching 50 degrees at light cruise. Not something I'd do again. Also inlet air temperature was always from under the hood as the cowl induction was a project not completed.
Next build is targeting mid 10:1 in SCR with a DCR approaching your 8.3-8.4.
I'll have to tune better. Need cold air. At least the cooling system is up[ to the task.
Kevin
Re: Smog Era 350 Vortec build.
My initial is 12 degrees, with a 30 degree total. Vortec heads aren't supposed to need much more than that. I started out at 15/33, and it didn't ping there either. This is also a fuel economy build, I have the QJ leaned out as far as I can and not have a lean surge at cruise.
So much to do, so little time...
Re: Smog Era 350 Vortec build.
What kind of mileage are you getting? Vortec's do great in terms of detonation resistancerfoll wrote: ↑Fri Jul 09, 2021 9:37 am My initial is 12 degrees, with a 30 degree total. Vortec heads aren't supposed to need much more than that. I started out at 15/33, and it didn't ping there either. This is also a fuel economy build, I have the QJ leaned out as far as I can and not have a lean surge at cruise.
Re: Smog Era 350 Vortec build.
Anybody can claim this and that yet run around with the timing retarded less than optimul.
Re: Smog Era 350 Vortec build.
Pulling timing back from 36 degrees to 30 total changed nothing but idle speed. 12 to 15 degrees on an engine with 9.6 compression and a small cam is nothing to sneeze at. I have stopped reading your responses because everyone is doing everything wrong in your opinion. Maybe you would be happier if I had a supercharger or a tunnel ram on my car. That would go well with my single exhaust and stock manifolds.
So much to do, so little time...
Re: Smog Era 350 Vortec build.
In my case, with a whack of advance and a lean cruise tune, I managed 20+ US MPG steady state highway. Lockup converter and ~2500 RPM at 75 MPH. Carb and distributor tune. Crippling exhaust. The 3700 lb heap still trapped at 108 or so. So I'm thinking not too bad.Elroy wrote: ↑Fri Jul 09, 2021 10:37 amWhat kind of mileage are you getting? Vortec's do great in terms of detonation resistancerfoll wrote: ↑Fri Jul 09, 2021 9:37 am My initial is 12 degrees, with a 30 degree total. Vortec heads aren't supposed to need much more than that. I started out at 15/33, and it didn't ping there either. This is also a fuel economy build, I have the QJ leaned out as far as I can and not have a lean surge at cruise.
FTR, not true Vortec but rather the old school RHS upgrade. Still iron though.
Last edited by skinny z on Fri Jul 09, 2021 8:18 pm, edited 1 time in total.
Kevin
Re: Smog Era 350 Vortec build.
Gotta admit it has quite the look. Sort of like the Australian burnout monsters that pop up on YouTube.
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Kevin
Re: Smog Era 350 Vortec build.
I'm not there yet. The car is and 84 El Camino, not exactly an aerodynamic body. It has a 308 gear and a 350 C transmission. The converter is from askinny z wrote: ↑Fri Jul 09, 2021 8:06 pmIn my case, with a whack of advance and a lean cruise tune, I managed 20+ US MPG steady state highway. Lockup converter and ~2500 RPM at 75 MPH. Carb and distributor tune. Crippling exhaust. The 3700 lb heap still trapped at 108 or so. So I'm thinking not too bad.Elroy wrote: ↑Fri Jul 09, 2021 10:37 amWhat kind of mileage are you getting? Vortec's do great in terms of detonation resistancerfoll wrote: ↑Fri Jul 09, 2021 9:37 am My initial is 12 degrees, with a 30 degree total. Vortec heads aren't supposed to need much more than that. I started out at 15/33, and it didn't ping there either. This is also a fuel economy build, I have the QJ leaned out as far as I can and not have a lean surge at cruise.
FTR, not true Vortec but rather the old school RHS upgrade. Still iron though.
v6 and stalls around 2400 making it great for spinning tires but not so good for MPG. I have yet to make a steady freeway drive, only a few trips to the coast and back. Lot's of hills and passing. My 79 Impala has a Vortec engine. I had The stock roller cam reground to 200/208 and I used 1.6 roller rockers to obtain some lift from the small cam. Exhaust is headers with 2.5" Flowmasters. With a 2.73 gear and a 2.73 gear it consistently gets 18.7 MPG. The gear ratio difference is good for 2 MPG in theory, Hard to say If the headers are worth mileage over the iron exhaust.
So much to do, so little time...
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Re: Smog Era 350 Vortec build.
I've calculated all the DCR and SCR I can while speculating, the truth will come when I get the engine a part which is happening next weekend. From there I will measure everything out and see where I stand. Its simple just too hot to drive around right now and I need to get some brackets refinished etc anyway so the sooner the better.
Whats been on my mind as of late is the cam break in. I have an idea that takes a little more time but might be worth it.
Has anyone broken a cam in using stock worn out valve springs? I got to thinking, and figured I could just put the cam and lifters in, leave the heads on etc. and put the factory intake back on with the q-jet for the break in. Doesn't seem like a bad idea to me. If anything goes wrong, I didnt waste a bunch of time doing a head swap, headers, exhaust etc. Just some intake gaskets and break in oil. I could literally leave the wires on the cap and just stab the distributor and let er rip.
I have also been told the Mexican vortecs dont flow as well and I should do some minor bowl and exhaust work if I want to optimize what I have. I have spoken to a few guys about getting this done. One guy I spoke to wants to charge me $1800.00. I couldn't believe it.
Whats been on my mind as of late is the cam break in. I have an idea that takes a little more time but might be worth it.
Has anyone broken a cam in using stock worn out valve springs? I got to thinking, and figured I could just put the cam and lifters in, leave the heads on etc. and put the factory intake back on with the q-jet for the break in. Doesn't seem like a bad idea to me. If anything goes wrong, I didnt waste a bunch of time doing a head swap, headers, exhaust etc. Just some intake gaskets and break in oil. I could literally leave the wires on the cap and just stab the distributor and let er rip.
I have also been told the Mexican vortecs dont flow as well and I should do some minor bowl and exhaust work if I want to optimize what I have. I have spoken to a few guys about getting this done. One guy I spoke to wants to charge me $1800.00. I couldn't believe it.
Re: Smog Era 350 Vortec build.
How about a little DIY? There's plenty out there that describe the do's and don'ts. From most accounts it doesn't take too much for initial gains.ClassicRob wrote: ↑Sun Jul 11, 2021 7:46 pm
I have also been told the Mexican vortecs dont flow as well and I should do some minor bowl and exhaust work if I want to optimize what I have. I have spoken to a few guys about getting this done. One guy I spoke to wants to charge me $1800.00. I couldn't believe it.
Kevin
Re: Smog Era 350 Vortec build.
Using stock sbc valve springs for break in requires a few things. Eliminate any ex rotatores. replace with stock retainers remove the oil caps and any all spring seat shims.. You want the springs at max possible installed height. 1.75 1.77" ++.. Retainer to seal clearance must be verifued.. leave the oil shields off.
Get some GM EOS. Get some Isky Rev lube.
(moly di sulfide paste) Smear the moly paste on clean cam lobes.. you don't need a ton of moly paste.. oil it all up and install.. Oil lifters, set hyd preload by pushrod up down feel for O lash point, not
Spin pushrod.. up down....
Stock vortec springs will likely coil bind.
Stock rocker to stud clearance at max lift must be checked.
If when the comp xe cam goes south. buy a Isky cam.
This is what I am using to get max life out of Comp and other fast action hyd flat tappet cams.
You can too..
Www.molyslip.com. Moly slip E oil supplement.
Google it.
Get some GM EOS. Get some Isky Rev lube.
(moly di sulfide paste) Smear the moly paste on clean cam lobes.. you don't need a ton of moly paste.. oil it all up and install.. Oil lifters, set hyd preload by pushrod up down feel for O lash point, not
Spin pushrod.. up down....
Stock vortec springs will likely coil bind.
Stock rocker to stud clearance at max lift must be checked.
If when the comp xe cam goes south. buy a Isky cam.
This is what I am using to get max life out of Comp and other fast action hyd flat tappet cams.
You can too..
Www.molyslip.com. Moly slip E oil supplement.
Google it.