Hello, I'm looking for some suggestions/insight. I have 68 400 engine with 3.90 gears. As far as I know it is stock other than it has been bored .030 over. I am thinking about replacing the cam and I'm debating between an 068 and 041. I'm not building a race car, just looking for a little more performance. Can I even swap out my cam for an 041 or do I have to replace more parts due to the lift? Thanks.
Hello, I'm looking for some suggestions/insight. I have 68 400 engine with 3.90 gears. As far as I know it is stock other than it has been bored .030 over. I am thinking about replacing the cam and I'm debating between an 068 and 041. I'm not building a race car, just looking for a little more performance. Can I even swap out my cam for an 041 or do I have to replace more parts due to the lift? Thanks.
Only RA and HO cars came with 3.90 gears in '68. You probably have a 068 cam in already.
I would double check what engine you have. Also, you may have more work there than you think. How long since the last rebuild? You open up the block you could be inviting yourself into more work and parts. You have to keep in mind the high compression needs to be reduced so you can use pumped gas
Engine Test Stand Playlist: https://www.youtube.com/playlist?list=PLwoxyUwptUcdqEb-o2ArqyiUaHW0G_C88 restoring my 1968 Firebird 400 HO convertible (Firedawg) 1965 Pontiac Catalina Safari Wagon 389 TriPower (Catwagon) 1999 JD AWS LX Lawn tractor 17hp (my daily driver) 2006 Sequoia 2017 Murano (wife's car) 202? Electric car 203? 68 Firebird /w electric engine 2007 Bayliner 175 runabout /w 3.0L Mercuiser__________________________________________________________
Block Casting # 9790071 stamped YE, cam is stamped 9779066, just rebuilt the rear end stamped ZP. I'm unable to identify the heads. I've only put maybe 30k miles on it since I got it. Brought it to a machinist over the weekend and he said it's in great shape all he's going to do is hone, deck and maybe a valve job.
The heads are #215, if i'm reading the number correctly. It's a good head from a 68 400. Ron's Page says it would have come off a 350hp Grand Prix, had big valves and screw in studs. Would be a nice head on your 400. BUT... other sources list it, again as a 68' 400 GP head but with small valves. Have your machinist check it.
Id have your guy measure the cam lobes and if they are close to the right size then just use it. You're not going to find a new one made with as good of material as an original.
see if this helps, or confuses, there's diff YE blocks over the years, 400, 350 and a 455, but yours seems to be the 68 with the 066 cam which was the standard workhorse station wagon cam, that engine lists #15 heads, could be a misprint? maybe they meant 215? or somebody changed the heads, or ??
Ok..back to cam. Be sure to talk to your machinist/builder. You have to match up your power train, front or back.
I didn’t note your tranny. If an auto, be mindful you may need to use a converter with a higher stall than stock if you go with a “bigger†cam. ..and no point going with too big a cam if your heads won’t make full use of the added duration. Your rear gears will certainly allow for it. If you have power breaks, be mindful of lobe separation.
There’s a lot more to it than just picking out a cam.
I'm a hobbyist. Not a professional. Don't be hatin'!
The 15/215 heads are 10.5:1 on a 400 with 1.96/1.66 valves. The YE block in 68 is a 340HP 400. There is a way to tell if you really have a 68 block in there and that is the casting number and date. I can't recall where it is on the block but should be pretty easy to find. My 68 Firebird has a YE block in it but it's from a 1969 and that makes it a 350 265HP. Your 1968 YE should have had 16 heads on it and 066 cam according to that site.
Unfortunately my machinist only really recommended an RV cam which I don't know too much about.
This engine might have come from a 68 grand prix? This is from Ron's page
Head casting Number 215 Year 1968 Engine 400 Rated Horsepower 350hp (Grand Prix) Valve Size (Intake / Exhaust) 2.11 / 1.77 Chamber Volume (or Compression Ratio if Volume Unknown) 72-75 cc Stud Mounts Screw
Transmission is TH400 Automatic. I was going to get a 2500 torque converter if I got the 041 cam and an 1800 torque converter if I got a 068 cam.
Figuring out how much duration these heads can take advantage of is what I've been having a hard time figuring out. I do not want to overcam the engine but I don't mind making some improvements to make a bigger cam work. I can't find flow charts on these heads but Ron's page has flow charts for heads that seem very similar, maybe I could just use those for a reference?
Only way you're going to make that head work on that block on pump gas is to install new Pistons with a dish. Which means,basically, a complete rebuild. Or you could run 100 octane race gas at $5-$8 per gal. (Depending on where you live). You don't have to take my word for it though. Put it together how you want and see what kind of knock, ping, pre-ignition you get. Maybe you'll be the lucky one.
These are the pistons it has. I think they're badger. That's all I know about them. I think I'm going to try Crane Hydraulic Flat Tappet Camshafts 969681 with new springs, push rods, lifters, 1.65 rocker arms and 2500 torque converter. Maybe I'll replace the 7/16 by 3/8 rocker studs to just 7/16" studs.
Take it for what it’s worth but those pistons on a high compression motor is a recipe for disaster( go ahead ask me how I know). The ONLY thing good about them, in your situation, is that they sit about .028-.030 below deck reducing your compression ratio.
To answer your question...Badger pistons are fairly low quality cast Pistons designed for a low budget stock rebuild. Used in the right circumstance I'm sure they could be fine. I put together a motor much like yours with those Pistons and because of the high compression they lasted about a year and a half before two of them broke. Before that happened, and oil started spewing out the dipstick tube, it was great, as far as I knew.
Do yourself a favor and call Butler, or any reputable builder, and ask if they would build you a motor using Badger pistons. They will not because they know you will be back shortly with a broken motor and they would be on the hook to build another.