Okay the the geometry issues have scared me away from longer valves and spring pressure from the 11/32 stems,so has anyone used the 2.19/1.72 valves from show cars are they the flat non-tulip style Ishiftem recccomends and will they hold up to stronger spring pressures,I'm looking to set these heads up for a bigger cam than the one I'm going to run in the truck Don.I already got one set done with 2.06/1.72 valves out of a set of 817 heads with no port work,these are set up with those Competition products dual springs that had setup at 1.73 installed height.These heads I want to setup with the bigger valves and port work and springs for a bigger cam still less than .600 lift but with more duration.I've got a second block that I plan to build also.Just to make sure since I've got a set of 379 castings also the 333's are a better head to start with right?The 379's aren't capable of being ported to perform better than a set of ported 333's can they?
Porting 333 heads
- Thread starter 427John
- Start date
No John the 379's cannot be ported enough to beat the 333's.The pocket under the valves in both the 333's as well as the 817's are bigger in stock form than the 379's can be ported to .I've got a set of 2.19-1.72 valves from Show Cars,but I haven't looked at them yet,so I don't know about the "flatness" yet.I do remember that I was told by a good friend that they'd be fine for a mild roller[under 450 lbs.open] cam which is where I'd be concerened about the strength of the valve,as opposed to the lift.You wouldn't want more than 350-360 lbs.open on a flat tappet cam anyway.Any more than this would likely kill the lobes on the cam.
Thats what I was hoping to hear if I do end up going with a roller it won't be big enough to require more than that,I'm not a big fan of super high rpm just makes me nervous.I thought that was the case on the 379's thats why I left them in the shed,but I didn't want to put all the work in the 333's and find out 379's had enough metal to make a better port,some heads are funny that way.When you get a chance to look at those valves to check if they are the flat variety let me know,I'm about ready to pull the trigger on a set.
Save the 379s for someone wanting to do a restoration. The 333s when worked over will kick the 379's ass all day long
Yes John,and I "think" so,but I don't have anything[other than go kart valves] to compare them too.There is a very slight tulip area where the stem meets the head of the valve.We got my 380's short block finally assembled,cam degreed,oil pan and timing cover on,now it's on to the heads.
Pics Don,
Youve been here long enough to know some one is going to ask
Might as well be me
Steve
Sorry guys,I have no way to do that.I had forgotten how much "fun"
spirolocks can be,the rest was just the usual cam degree drill that one goes thru when things are a bit off,and correcting the timing tab/balancer marks[this set up was 8 degrees off].We also had to "massage" the 348 pan to clear the front 2 rods on the engine,but it's bottom end is done,and all bagged up for the next installment.
spirolocks can be,the rest was just the usual cam degree drill that one goes thru when things are a bit off,and correcting the timing tab/balancer marks[this set up was 8 degrees off].We also had to "massage" the 348 pan to clear the front 2 rods on the engine,but it's bottom end is done,and all bagged up for the next installment.
Well the short block is all done now.All that I can say is that good measurements are a must.We sorta messed up somewhere as on final assembly,the deck come up at .014 down after the block was squared.The number 3 and 4 main bearing clearance is just a bit too tight,but not enough to bother with for this low rpm engine[ 6200 max].Thank God that Show cars is once again stocking the .022 steel shim head gaskets since all the other composite or multi layer gaskets made are way too thick,the .030 thick Cometic's being an expensive exception.This assembly took very minor work to bring it into balance,no Malloy metal needed at all.The non file fit rings came out fine at about .019 on both the top and second ring.Some where there was something off with the cam timing.The lobe seperation came in at the prescribed 108 degrees,but it was retarded on the centerline.Either the cam[108 centerline,224 intake-23o exhaust @.050..517 in..520 ex.] was a little off,or the engines crank key way.or something in the timing gear set was off.It was supposed,according to the cam card ,to have an intake centerline of 104,but that came out at 110 degrees.I am using a roller timing chain kit/Torrington bearing,and 9 keyway crank sprocket that I bought from Bob Walla.Advancing the bottom gear to the +4 brought it to 106[2 degrees advanced] which I can live with since I'm going to be running the Rhodes V-max adjustable hyd.lifters in here.If you're going to use an oil pump[M55HV] and pick up.you MUST be prepared to ,once the pick up is positioned where it needs to be,weld the pick up to the pump.Once pressed into place,it would flop all over the place!The balancer that I got was supposed to be for early engines,but it,on my engine with the stock timing cover was off 8 degrees at TDC.Easy fix,but this just shows that checking and correcting things are mandentory if you expect this thing to run it's best.The only thing left to do is to cc the block,add the gasket cc's and check the head cc's so I can figure the actual compression ratio.The KB pistons are rated at 10.8-1 when using a 4 inch stroke and a 6.135 lenghth rod.My set up is that same piston,but a 6.385 rod and a 3.5 stroke 409 crank.With this set up,the pison comes up correctly at the top,but because of the shorter stroke,won't be as far down in the cylinder at bdc,resulting in a lower compression ratio.If I'm figuring it right,I should come up in 10-10.2 range.The head package will be ported 817's with 2.19 intakes and an Edebrock Performer RPM intake.The initial carb will be a 750 cfm unit,and we'll have to make headers.I have some ideas about tube size,primary tube length,collector size,ect.but nothing is finalized there yet.If it was going in to an X frame car,a set of tri-y's from Doug would be damn near perfect.
I really like the sound of the numbers for your cam the 108 lsa should give it a nice rowdy idle,it sounds close to the ZZ502 BBC that I wanted to duplicate,I'm guessing your lift #'s are with 1.75 rockers, what cam is it?Do you happen to have the weight of the +.250 rods?What is it going into if not an X-frame?Any chance you can get a video of it when you get it fired?
The lift posted was as on the card@1.7 and my Crane roller rockers are 1.8's so add about .030 to those numbers.Because this engine is destined to do some long range driving,I'm going with the adjustable Rhodes lifters to bolster the low end in the under 3,000 rpm range to help the mileage when cruising at under 2,500 on the highway.'m going to run a 700r4,a 2800 lock up convertor,and a 4.10 gear and a 28x10-15 drag radial.I might be able to get some of the carting guys to help me film it once running.The cam it's self is one of Aubreys cam designs which basicly change the lobe separation from the COMP Extreme Energy big block grinds from Comps more standard 110 lobe separation angle.Aubrey is a top end max hp guy and usually does not advance[108ls-108 center] his cams but the cam card said that it was. Aubreys cams are ground by Comp.I do know that it's installed with 2 degrees of advance in it now.That ZZ502 cams a hyd.roller isn't it? That would be a nice cam for your 427 incher.I'm sorry,I don't have the weight numbers on the rods.They are made by Wheeler,and also availeable from Eagle,Scat and on up.These are fairly heavy.Right now the plan is an early S-10 for the engines home.
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Thanks,just trying to help.Failure to check this stuff and correct as needed,especially one that was off this far,would have resulting in a hot running,gas hogging DOG of an engine package.Just the timing tab/harmonic balancer issues would,if one used the zero marks would have resulted with the engine being 8 degrees retarded.
I thought it looked suspiciously similar to the comp 274 XE BBC grind,the ZZ502 is a hyd.roller with nearly identical @.050 numbers as yours with 110 lsa,it looks almost as if comp or GM copied the other,while the rollers usually have a steeper ramp it wouldn't surprise me if GM kept the ramp conservative to promote valvetrain longevity and stability after all these were production crate engines with warranties.It is conceivable that a conservative roller ramp and aggressive flat tappet ramp could be nearly identical,but thats only speculation based on the similarity of the numbers.I figured I would try to get the ZZ502 profile translated onto a hyd.flat tappet cam and thought the cam grinder(Delta) may be able to confirm that speculation,but I may consider getting the cam you have Don.