Thread: 429 question - hey EriK? Dave? Anyone?

Tweet

As I'm getting closer to buying a rebuilt long block, I've come across lots of info which is hard to sort out. The guy who I am planning to get my longblock from said to go with roller rockers and heavyduty springs for the heads. He said it you put any kind of a performance cam in with any lift to it at all, that the stock rockers just can't take the lift. I also mentioned the hyperpeurotic flat top pistons, which he said were a good idea, because as you add lift to the cam, you loose compression in the cylinders, so you have to gain it back with no depressions in the pistons, or whatever you gain from the cam, you'll lose from stock pistons. Does this sound right? Roller rockers add about 500 to the build with the flat top pistons.

I dont agree that the stock rockers will not handle it, Its that if memory serves me correctly, You have the heads with the non adjustable pedistal mounted rockers. And if you change the cam specs, the push rods will have to be changed to compensate for the added lift of the cam. And you should not reuse old rockers with new push rods, as they have develop a wear pattern from the old set. So ya the whole system should be updated if you change your cam profile. I dont think you need rollers, and heavy springs, I think I remember you are going for a mild build anyway, that does not make it mandatory for rollers with heay springs. Sure in the perfect world where money is free it would be great.

Thanks mooneye777

I had talked to a different guy to start with, and he didn't seem to think it was necessary, but the second guy there who I talked with seemed to think this was necessary. The cam for the build is an Elgin series 2 street performer that I guess is reground by Crane( who does the machining). I just don't have any experience with this size mototr, or any performance builds, so this is new territory for me. But yes your right, I'm looking for a mild build!

Steve, all these things need to be coordinated as a combination to achieve a particular goal. When someone says something like "heavy duty springs", it scares me a little. With any cam you buy, the manufacturer will have engineered the EXACT spring package to work in harmony with that particular camshaft and its particular characteristics.

I like using Crane Cams site, because it gives you all the info you need on one page.................
Idle quality
How to use the cam (daily driver/race/whatever)
Cruise rpm's
Operating rpm's
Minimum rpm's
Maximum rpm's
Valve float rpm's
Static compression ratio to use with this cam
All intake and exhaust valve opening and closing events
Lobe separation angle (at the bottom of the page under where it says max lift, there will be two values given which represent the centerline of the intake and exhaust valves. On this particular cam that I'm giving a link to, those figures are 107 and 117. Add those together and divide by 2 to arrive a a lobe separation angle of 112)
Intake and exhaust valve lift with a particular rocker ratio
Cam timing at SAE specs
Cam timing at 0.050" tappet lift
Springs required
On-seat pressure at installed height
Full spring pressure @ full lift height

Here's an example of what I'm talking about. This might be a cam to choose for a BBF, using the motor as a daily driver and building the c.r. at 8.0 to 9.5
http://www.cranecams.com/?show=brows...tType=camshaft

Roller rockers would be ok, but not essential. I would have the heads machined for regular rocker arm studs and go to the adjustable rockers and a set of guide plates along with the correct length pushrods. As Tech mentioned, the Crane site lays it out very nicely and in plain English..... or just say to heck with the cast iron heads and spend the big $$$$$ on a set of Edelbrock Performer RPM heads!!!!!!!!!!!!

Originally Posted by DennyW

Cam duration is what kills the compression, at least on what you are talking about. I run over .500 lift, with a short duration, matching springs to the cam, and regular push rods, and rockers. I have had no problems. On a stand mounted shaft rocker assembly, many go to the adjustable rockers, because when someone does a valve job, they don't take the time to measure and grind the stems for the difference. I do on all the ones I build. Therefore, I don't need adjustable rockers on my hydraulic cam. Solids is a different story. The goal is to have the right pivot angle, and keep the rocker centered on the valve stem, and...to put the hydraulic lifter in the center of the plunger position when installed. 2nd stage cam, 115lbs on the seat should be good.

ps: Besides...erik is a Chevy man, and Dave has his guy do that stuff.... Just joking fellows...

Denny,I might be a Chevy guy but I can tell you that big block Ford will take big block Chevy roller rockers.

Thanks guys! The crane site is great. It explains a ton of stuff. My problem is what is a rough idle? I'd like to get some HP and the engine is 11.0 to 1 compression stock. So I'm not sure how to proceed. It will be a weekend driver only, mild performance build, not too tame, with enough get up and go to feel like a hot rod, versus my toyota truck. Pretty confusing to figure it all out.I've been told the 1968-71 429's put out around 350 hp. I can't find any site to confirm this, and have heard huge variations in actual HP. I would like a smooth idle engine with umph to move when needed, but will never be racing it!

Erik
I got you confused with Paul Kane. But advice is advice thanks, all of you. I'll spend some time on the crane cam page, and go from there!

The big block Fords make tons of torque, anything you can do to increase the low rpm torque will add to the overall power and not effect driveability issues...


PS---I have built my own engines many, many times and even logged a few years as a machinist.... I no longer have the equipment, no flow bench, no balancer, no boring bar, and no hone.... Guess that makes me a fool to hire someone else to do the machine work, cnc and flow the heads????.... Don't worry Denny, I can still build them with the best of em..... I'm also even smart enough to realize that good engines and heads require good machine work.... What is it you're actually building now???? We took the win and runner up today at the strip, how did your cars do??????

Oh yeah, just kidding.................

Nobody could pay me enough to work on a ricer.... Sorry, just not in my nature.... Got no use for them. I'd quit racing and building if that's all there was to work with....

Originally Posted by Dave Severson

Roller rockers would be ok, but not essential. I would have the heads machined for regular rocker arm studs and go to the adjustable rockers and a set of guide plates along with the correct length pushrods. As Tech mentioned, the Crane site lays it out very nicely and in plain English..... or just say to heck with the cast iron heads and spend the big $$$$$ on a set of Edelbrock Performer RPM heads!!!!!!!!!!!!

have a set of ford iron heads in the shop i set them up with guide plates and use bbc rocker studs i go with adjustable valve train any time i can it has not so much to do with the setup height of the valve stems for the right preload for hyd lifters but if the engine has been deck or heads have been milled they could be going up or down hill if not tru deck and other things to so i go adjustable

Originally Posted by DennyW

We are building 2 hi winding Honda's this year, believe it or not. I just shook my head, but that's what they want to run this time. All I did was joke about them all day with the guys. Even got them to ribbing them. Got to keep the smiles going...right ? Did some work on my other motor today, since I have a few parts to go in it. Next week, the chassis, and setting up the tunning on the Honda's to dial them in.

Hey Denny .W If you need any Tech info on Imports ask my Nephew Thill-1 He has that Street Honda that run's 12.10 with no spray on street tires. I can tell you he's very good with them import Drag car's

Hey Denny and Dave, thanks. I like the smooth idle thing, and avoiding an extra 500 bucks for now, will get the engine in the truck before the end of the year, I figure my friend who runs his own shop can drop the engine and tranny in, tow the truck to me, I'll wire it and do the fine tuning and go from there. By having him do the install I keep the warrenties on the engine and the tranny and I know the welds on the new motor mounts will hold, plus the engine will be in at tyhe right angle.
Denny those Hondas do rev high and perform well, but it is hard to think Hot Rod and foriegn imports, but look at the old opels, austins etc...
Dave I'd love it if this engine gets around 350 hp. I'm told thats not too hard with a 1970 head set and engine block. What do you think?

A mild built 429 Ford can make easy 350 HP . And you should be able to make 400+ HP with a camshaft 480 Lift and New stock rockers and Pushrods . No need to try and over build that 429 for the street .

That is music to my ears Tango!