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Location: Colorado Springs Colorado/Thousand Oaks Ca
Posts: 1,719
I'm Going To Build A Smooth Idle 427
I had some parts laying around and wanted to turn them into something, so I decided to build this simple 427 BBC. As with any engine build its starts with the heads first. I used a 820 production oval port head casting, not because there the best casting to start with, but because I had them and they were virgin, until I got my hands on them. I installed bronze guides, they were cut for piton seals, and honed them to size, then the seats were cut for 1.880 2.190 valves, Ferrea valves were used. Isky 805 DO springs were installed setup @ 110 pounds on the seat, 280 open, setting the stage for the cam used. Heads were surfaced and CCs were set @ 114. Some pictures:
Just to clarify, it sounds like you are starting with heads that most Chevy performance guys would consider ok for a 350-400hp engine with their normal, mortal hands....
In to see the documentation of the performance you squeeze out of these..... especially using a small cam for the smooth idle requirement.
Location: Colorado Springs Colorado/Thousand Oaks Ca
Posts: 1,719
My camshaft choice, a copy of a 1969 396 350 HP or 1969 427 390 HP factory hyd cam 214/218 @ .050 .460/.480 lift, I wanted a dead smooth idle with lots of vacuum thats why the factory cam was chosen. I had my partner Spirro over at Redline grind it for me on a 1960s GM cam core, I used 1970s NOS TRW hyd lifters. Pictures:
Location: Colorado Springs Colorado/Thousand Oaks Ca
Posts: 1,719
Originally Posted by Battenrunner
Just to clarify, it sounds like you are starting with heads that most Chevy performance guys would consider ok for a 350-400hp engine with their normal, mortal hands....
In to see the documentation of the performance you squeeze out of these..... especially using a small cam for the smooth idle requirement.
You do know I expect low 11s with a 700 RPM dead smooth idle from this engine in my Chevelle, we will find out.
Location: Colorado Springs Colorado/Thousand Oaks Ca
Posts: 1,719
My compression will be set at 9.7, Racetec pistons will be used 1.5/1.5/3.0 ring pack. GM production 402 rods will be used blue printed with ARP bolts. A STD STD 402 cast crank is used with no trickery. More pictures:
You do know I expect low 11s with a 700 RPM dead smooth idle from this engine in my Chevelle, we will find out.
That will be an impressive feat with a truly stock, mild pattern cam like you show there, not a racing “stocker” cam with low vacuum and huge duration.
Curious, how low of rpm can you go on your dyno and get an accurate pull? This sounds like also a good truck motor as well. Any port work done to the heads? Something different for a BBC.
Location: Colorado Springs Colorado/Thousand Oaks Ca
Posts: 1,719
Originally Posted by Battenrunner
That will be an impressive feat with a truly stock, mild pattern cam like you show there, not a racing “stocker” cam with low vacuum and huge duration.
Location: Colorado Springs Colorado/Thousand Oaks Ca
Posts: 1,719
Originally Posted by olds 307 and 403
Curious, how low of rpm can you go on your dyno and get an accurate pull? This sounds like also a good truck motor as well. Any port work done to the heads? Something different for a BBC.
The heads are ported. Probably could pull it down to 2500 RPM.
Location: Colorado Springs Colorado/Thousand Oaks Ca
Posts: 1,719
Originally Posted by Battenrunner
Looking good on the pics of the parts with the shortblock....
Have you degreed the cam yet?
What is the planned ICL that you are going to aim for?
Carb plans for this one?
I installed the cam at a 108 intake centerline, 4 degrees advanced. I have an arsenal of Q-Jets to try on it, you'll have to come down for lunch this week, I should have it on the dyno!
Very cool build. 292 CFM is crazy head flow... with that tiny of a cam, that would be an interesting exhaust manifolds vs headers test. Gotta love the "do more with less" builds.
Location: Colorado Springs Colorado/Thousand Oaks Ca
Posts: 1,719
Yes, thats the point of this build: To see IF theres HP to be had with extra air flow through an otherwise stock cammed engine, it will be interesting. Basically a 390HP 427 had a advertised 390 HP, pure stock racers say the 390 HP 427 is a dog, with 10.25 factory compression it should make 390 HP stock, now my engine has 9.7 compression, but a modern ring pack, with ported heads I say it will be over 400 HP, but we will see, there is absolutely no trickery any where in this engine, just good machine work.
Last edited by VORTECPRO; April 12th, 2021 at 04:45 PM.
I know we have non olds forums here. Why the hell don't you put this elsewhere. Go play on a chevy site.
Wow, that doesn't seem like the kind of classy comment I would expect from a longstanding member....
He isn't forcing us/you to look at this 427 Chevy build, it is by choice.
Also, who's to say that Vortecpro won't build a 455 Olds in a similar way with a mild cam/ using good machine work and some ported stock Iron heads for a comparison/baseline in the future?
I personally like to read about all brands of engine builds that stretch outside of either plain-jane stock or full race unobtanium, especially if they are likely to surprise with better than expected results in power.
Wow, that doesn't seem like the kind of classy comment I would expect from a longstanding member....
He isn't forcing us/you to look at this 427 Chevy build, it is by choice.
Also, who's to say that Vortecpro won't build a 455 Olds in a similar way with a mild cam/ using good machine work and some ported stock Iron heads for a comparison/baseline in the future?
I personally like to read about all brands of engine builds that stretch outside of either plain-jane stock or full race unobtanium, especially if they are likely to surprise with better than expected results in power.
Battenrunner
To some degree I hear you. However for how much crap has been laid here he should go to a chevy site. I agree I like seeing other projects. However I want to be here to see OLDS related builds not a boring Chevy build. I'm putting one of those together as we speak but would not put build details here. Just saying.
Battenrunner
To some degree I hear you. However for how much crap has been laid here he should go to a chevy site. I agree I like seeing other projects. However I want to be here to see OLDS related builds not a boring Chevy build. I'm putting one of those together as we speak but would not put build details here. Just saying.
Then stay out of the non-Olds-Engines forum, pretty simple.
Location: Colorado Springs Colorado/Thousand Oaks Ca
Posts: 1,719
I can post a video. My goals were many:
1. Use parts I had lying around
2. Have a dyno mule to test Q-Jets
3. Smooth idle with lots of vacuum
4. Test the effects of air flow on a stock type engine
I will try and give a cost break down, its more about using parts you have and turning them into something usable.
0 Block, trade for heads I would never use
100.00 Used virgin 402, crank, rods, balancer and misc
75.00. Virgin 820 heads
16.00. Valve guides
120.00. Valves
90.00. Springs
10.00. Valve seals
3.00. Valve keepers
45.00. ARP rocker studs
40.00. Comp 3/8 guide plates
95.00. Head gaskets
200.00. Cam
40.00. TRW lifters craigslist
45.00. Timing chain
30.00. Cam bearings
60.00. Rod and main bearings King
35.00. Oil pump
12.00. Oil pump shaft
10.00. Oil pump pick up
60.00. Comp roller tip rockers, 3/8 moly pushrods .080. trade
650.00. Pistons and rings
14.00 Pan gasket SCE
7.00. Timing cover gasket
7.00. Rear main seal
70.00. Valve covers
16.00. Valve cover gaskets
14.00. Brass freeze plugs
12.00. Misc stainless bolts
20.00 Valley tray
20.00. ARP rod bolts craigslist
30.00. Timing pointer
Why test multiple Quadra jets? Are they set up with different jets,rods,hangers and its quicker to just change carbs? A headers vs manifold test on this engine would be informative as well. Are you going to start with the factory timing curve? I am very curious of what the optimal timing is for ported heads vs stock heads.
Location: Colorado Springs Colorado/Thousand Oaks Ca
Posts: 1,719
Originally Posted by oldsmoboogie
Why test multiple Quadra jets? Are they set up with different jets,rods,hangers and its quicker to just change carbs? A headers vs manifold test on this engine would be informative as well. Are you going to start with the factory timing curve? I am very curious of what the optimal timing is for ported heads vs stock heads.
I wanted to try my new Q-Jet against my base line carb. All tests were done with 2 inch full length headers with mufflers. I think it likes about 40 degrees total timing, although it was humid during testing, that always seems to want more timing. I always run a locked out dist.
Location: Colorado Springs Colorado/Thousand Oaks Ca
Posts: 1,719
When I run this in my car it will never see anything under 4000 RPM, what I was concerned about was how far it would carry the power, seeing it would run between 4000-6000 RPM in the car. My goal was a low 11 sec car with a dead smooth idle, and from the data that will be no problem.
April 8th, 2021, 07:42 PM
