65 Chevy II 409 Swap

[409envy]

Finally finally finally!!! The short block is together!!!! Will be taking final measurements of the chamber volume this week and start thinking about cam profiles. It's all coalescing now. Good news is that my pistons look to be "0" deck or possibly even a couple thousands out of the hole which should help with compression. It's beautiful...spins over very easily!!!! Can't wait !!!

 

[409envy]

goood news from my builder. compression ratio is going to be approximately 11.25:1. I'm really happy it didn't wind up less. Talking about cam profiles now. max lift is .580". We are targeting a duration @.050 in the low 260's. LSA is going to be ~104... custom grind. if any of you builders have any suggestions for cam specs please chime in.

 

[La Hot Rods]

That's good more is better.

 

[Don Jacks]

In my opinion,that's waaaaaaaaaaaay too much cam for a street driven car.The centerline is too tight,which will make the engine very "peaky".The specs that you mentioned would be good for a race engine turning lots of rpm[well over 7,000],but will have no power below 3500-4000.Duration in the low 240's.and a 108-110 centerline would be my idea.Perhaps Dan, DaveJim and Jim ,Brian,or Ronnie would have a better idea since they have much more experience on race set ups.This is a bit above my pay grade.

 

[409envy]

Car will be more strip than street. I am setting it up as an actual representation of a period race car which means an engine with an anemic cam is not going to fly. I also have no vacuum accessories and no power steering so I will not have to worry about that. I'm sorry I didn't make that clear enough in previous post. I want to pump up my cylinder pressure as high as I can get it as I will be running race gas mixed with 93 for any time I drive it on the street. Additionally the fact that I have an extra 40 cubic inches will bring the RPM range down a little as compared to a factory displacement engine. The reason we are tightening the lsa up is because I didn't go with 12:1 or higher so I want to maximize what compression I have.

 

[dm62409]

Everyone has a different take on how much cam (drama) they can stand to drive. That being said, I'll just throwout the cam specs that I'm currently running in my 62 Belair streetcar, 446 cu. in. 409 , 11-1 cr. , Comp Cams, solid lifter , Max Area lobes, only has .486 gross lift, 110 lb. seat pressure springs, dur.@ .050, 250 In. 260 Ex. 109 lobe separation , 106 intake centerline. Max Area lobes has faster ramps for more area under curve. Lower lift allowed less spring pressure for easy breakin. Cam has pretty rough idle, and really pulls hard from 3000-6000 rpm, would probably go higher , but I have the rev limiter set at 6000 , and see no reason to push it any farther on the street. Not saying this cam is for everyone, just throwing it out there for you to compare to. As a note , this cam was to be ground on a 108 LSA, but came on 109. I used it any way, as I didn't think the engine would know 1 degree difference.
I should also add , I used the solid lifters with the small EDM hole in the face of the lifter for direct oiling. This is great insurance for the lobes. However , they should be taken apart and washed out, as there is usually some metal trash from the EDM process still inside.

 

[409envy]

Dave, I will be using EDM tappets as well... thanks for the tip about the left over material I will definitely go through the lifters and clean them up. I am also having the cam plasma nitrided which will really help with longevity and wear.

 

[jim_ss409]

As you know the amount of overlap you have will pretty much dictate how the engine sounds and idles. So it sounds like a tight LSA is the way to go in your case.
There's no doubt a 104 LSA along with low 260's duration would really give you that 60's race car sound.
It does make the engine a little hard to tune for the street and it will of course be harder on gas, but I'm sure it'll make great power.
I've noticed that a lot of the Engine Masters engines use tight LSA's with good results and David Vizard often points out that most builders tend to use LSA's that are too wide for maximum performance.

104 is really tight though. I think it'll work well and sound radical but I'm not sure I'd go much past 256 int. 262 ext. on a 104 LSA. but that's just an opinion based on no real experience with that much duration on a tight LSA. (be sure to check your piston to valve clearance)

I did help a guy I know spec out a 230/236, 106 LSA for a 476 ci. stroker and he loved it.
He wanted a bit of a lopey idle and good midrange but didn't want to rev the engine much past 5,200 rpm.

Joe Sherman used a 265/270 on a 108 LSA for the 437 ci. stroked 348 in this article. It peaked at 6,900 rpm.
http://www.hotrod.com/how-to/engine/hrdp-0911-chevy-w-series-engine-build/
I bought that engine from Joe and I can assure you that it idled like a race engine.
It had 51.5 degrees of overlap. If you went with 256/263 on a 104 LSA you'd have the exact same amount of overlap. I would expect it idle much the same but the horsepower would of course peak at a lower rpm, like maybe 6,300 or 6,400? and maybe shift at about 6,500 or 6,600?

Oddly enough, when I put together the new engine I'm running in the 55 Chevy, I went in the opposite direction. I wanted a smoother idle and didn't need any midrange because of the 6,000 rpm torque converter, so I went with a 112 LSA cam. (263/274 @ .050)
That's "only" 44.5 degrees of overlap so it idles pretty smooth by race car standards.

You might be the first one on the site to use a 104 LSA if you go that way.
I'm thinking it might be just the thing for what you're aiming for. I'm pretty sure it'll work as long as you don't get carried away with the duration.

 

[jim_ss409]

I came across this article comparing cams with the same duration (242/252) but different LSA's.
They compared a 104, a 110 and a 114.
I know it's a completely different engine but it looks like the 104 LSA made the most average power.
http://www.cranecams.com.au/pdfs/MAY14-Lobe_separation_article.pdf

 

[boxerdog]

I don't think it's too uncommon in the SBC world, especially circle track stuff, even pushing the ICL into the high 90s. And, everyone has a different idea about street driving. My latest one is getting close on intake valve to piston clearance, however. It is 260/266, .670/.697 on 107. The ICL is installed at 103. To be honest, it wouldn't be fun to drive every day but I like the way it sounds.

 

[409envy]

Great input guys I really appreciate it!
I originally found a comp bbc grind that had .570 lift and 256/262 duration @ .050 with a 108 lsa. My builder liked that grind as a starting point but suggested tightening up the lsa to 104 so we could up the cranking compression and get that radical idle I am looking for. I don't think we will go much beyond that duration due to ptv clearance. I can't wait to hear this thing run! I will be chassis dynoing the combo so I will have actual numbers to share with you when that happens.

 

[boxerdog]

Outstanding!!

 

[409envy]

Updates...
Headers are back from the welder. They required some tweaking but they fit. Just have to fabricate take offs for stock exhaust and weld on flanges.

Cam shaft selection is finally done. As I had mentioned before we were contemplating a 104 lsa cam but after talking to comp cams we found out the tightest grind they have for a 409 is 106.

Specs:
.050 duration 254 int/ 260 exh
.612" intake / .598" exhaust
106 lsa. (Will probably install at 105 to account for chain stretch)

 

[409envy]

Channeling Dyno Don right now! I am really happy with how this thing is coming together!

 

[409envy]

Couple shots of the engine bay. Im mocking everything up with the 348 so there are no suprises with the 409.

 

[benchseat4speed]

Oh MAN is that sexy Plain black steelies and bias plys with those big ol dumps right behind em...and that thing is gonna bark with that cam dude I can't wait to hear it

 

[409envy]

I decided to revisit my oil pan setup for a couple of reasons. The first was ground clearance, with the original version the sump was way to close to the ground for comfort. The second was capacity. My engine builder wants to have at least 7 quarts of capacity from the pan. With that in mind i decided to build a pro stock style pan with a nearly full length sump. Im going to fabricate an oil control baffle that will prevent the oil from climbing the pan on hard braking or acceleration.

 

[409envy]

While the oild pan and headers are off being finished i started on my shock towers. I have the passenger side pretty much in. Just some grinding and some filler and then a coat of semi gloss paint and it should look great.

 

[Ronnie Russell]

Looking great. Well done.

 

[409envy]

I am continuing to make slow progress. My cam finally showed up after a month. The nitriding process held everything up. I went with cometic mls head gaskets. They should be arriving in the next few days. All thats left to do now is degree the cam and install the heads to measure for push rod length. The pushrods will be the last thing to order. I also did a little bowl blend and cleanup under the valve on my 583's.