468 going together, need some advice

[BossHogg69]

I'll start out with a few details on my build. I have a shortstep '69 C10, that has a TKO-500 (3.27 1st gear) and 3.73's out back. I pulled the 454 out to wring a little more hp from it and here's what I'm using top to bottom:

Holley 870 Street Avenger
E'brock RPM-O Air Gap (port matched to heads), 1" open spacer
E'brock RPM Marine Oval Port heads, 290cc intake, 110cc chamber with 2.25" intakes, 1.89" exhaust valves, bowl blended and gasket matched.
Crower valvesprings (68340-16), 10* locks, retainers
Comp Magnum pushrods
Comp flat tappet lifters
Crane full roller rockers 1.7:1
Cloyes Hex-a-Just Billet steel true roller, Cloyes Quick Buttom timing cover
SRP 212136 pistons, .060" over, -23cc dome
GM 'truck' rods, ARP bolts
GM cast crank
GM 2 bolt block, ARP studs, piston will be sitting .010" in the hole.

Now, during my parts hoarding phase (the past year) I picked up two different cams along the way - one is an Extreme Energy 4x4 278, #11-243-4.
http://compcams.com/Cam_Specs/CamDet...?csid=402&sb=0

The other is this one - http://compcams.com/Cam_Specs/CamDet...?csid=398&sb=0 a XE294 #11-254-4

Now, I know I'll get the 'just go hydraulic roller' and I'm not interested in that, my money is spent, and heavy hydraulic roller lifters in a BB with 2.25" valves is good for valve float after about 5500rpm. I'd like to have a solid roller, but I'm not interested in running valves at all. I am however interested in making some good midrange with a decent top end charge. I'm having the motor built for 10.8:1 CR with a .039" head gasket (tentative). The heads' deck surfaces have been cleaned up, and I expect the chambers to cc out @ about 108-109. I've been looking into the effects of the bigger cam on my dynamic compression ratio (the one that means the most) and the 294 will be down compared to the 278 cam (8.0:1 vs 8.5:1), but I'm wondering if the bigger cam will make up for this through the midrange and top end? I know you've all seen/read different builds online like this http://www.carcraft.com/techarticles...evy/index.html. I will be disappointed if I don't get 550hp and 570lb-ft out of this thing if I use the 294 cam, but does anyone think I might be better off with the 278? Naturally I want this thing to have a hard hitting idle (who doesn't), but I want to be able to walk the walk, not just put the biggest cam in there and have mismatched combo. This will be a street/strip/toy btw...

Sorry for the forever long post, I just want to get all the info out there.

[Ont67shortbox]

I Have a 427 with basically the same build except I went with ported 241 Chev heads at 113 cc.I picked the Comp xe282s-10. specs are 244/252 @.050- .590/.598 lift. works from 2400-6800 and has great mid range and top end.I realized the rev difference with the 2 engines, but I think it would work good in a 468 as well. Just go to Camquest type your info and start there.

[BossHogg69]

Yeah, I did the CamQuest deal on my PC, but it is a pretty basic simulator. The numbers were good, but I just wanted to see if anyone had some real dyno numbers, hard facts or timeslips.

Ont67shortbox - what do you shift your 427 at? what kind of guts do you have in that badboy?

[james colbert]

A 294 advertized isnt that big, lol. Thats a baby for a bbc. Give me a call 5012812341

[BossHogg69]

it's not the advertised duration I'm worried about, it's 250* @ .050", which isn't huge, but I just want to make sure everything works together. I was a little worried about the dynamic compression being too low, and killing the bottom end.

also, I do need to add that I have power brakes and a/c on this truck.

[Rodms]

Talk to DJ about the 468,I don't do COMP anymore.If I can buy a different cam for twice as much I will,DO NOT ASK!!!!

[CreditGod]

550 horse you better use some h-beam rods and that little 294 comp cam will not ever get you too 550 hp call that guy he is correct or call my dad his name is mike byrd 903-356-5655 he builds bbc all day long he will shoot you straight

[Ont67shortbox]

I just fired mine 2 months ago,have had it to the track 3 times,best so far with alot more tuning and suspension work to do is a 12.68@105.The rings are probably not fully seated yet.I was shifting at 6400.

[Ont67shortbox]

My basic build is a 427 .030 over,forged pistons with a .250 dome,open chamber 113 cc 241 casting Chev heads,truck rods,cast crank,10.8-1 comp,2.25/188 Ferrera valves,dual plane and 800 Holley, I have a turbo 350,3000 stall convertor,and 3.73.Going to redo the front and rear shocks and springs for better weight transfer.and probably change out the convertor and gears,I know there is alot more performance to gain.Mine is an all steel 67 short box,I am pretty happy with the running mid 12s in a street truck,but know I can go faster .

[Jim_PA]

Do some homework on solid lifter flat tappet cams, I'll be swapping out my hydraulic cam for one soon. Should have done it this way from the start

[BossHogg69]

Originally Posted by Ont67shortbox

My basic build is a 427 .030 over,forged pistons with a .250 dome,open chamber 113 cc 241 casting Chev heads,truck rods,cast crank,10.8-1 comp,2.25/188 Ferrera valves,dual plane and 800 Holley, I have a turbo 350,3000 stall convertor,and 3.73.Going to redo the front and rear shocks and springs for better weight transfer.and probably change out the convertor and gears,I know there is alot more performance to gain.Mine is an all steel 67 short box,I am pretty happy with the running mid 12s in a street truck,but know I can go faster .

I'd be happy with low-mid 12's too, our bottom ends are pretty close.

Originally Posted by Jim_PA

Do some homework on solid lifter flat tappet cams, I'll be swapping out my hydraulic cam for one soon. Should have done it this way from the start

I thought about doing this from the get-go, but this truck will see more street time than track time, and I really wanted a maintenance free 550hp, but that might be too much to ask!

[Jim_PA]

Originally Posted by BossHogg69

I thought about doing this from the get-go, but this truck will see more street time than track time, and I really wanted a maintenance free 550hp, but that might be too much to ask!

The way I see it... if I'm not under the hood a few times per year, I'm not having any fun.

adjustment shouldn't need to be checked any more than once per year from what I'm hearing. And most people say they only have to do one or 2 valves if any.

[Ont67shortbox]

Jim, I reset mine after breakin and there were 2 that actually needed adjustment,now that racing is over I will back them off and reset them in the spring.

[drag_72]

i just put a solid lift cam in mine. i have a 462 (.30 over 454) i had a hydraulic 292 .550 lift and i went to a sold split duration 307/310 with .575 .590 lift im starting it tomorrow

[BossHogg69]

Originally Posted by drag_72

i just put a solid lift cam in mine. i have a 462 (.30 over 454) i had a hydraulic 292 .550 lift and i went to a sold split duration 307/310 with .575 .590 lift im starting it tomorrow

well, don't forget to get us a video!!

[ripdog28]

The way i see it, Solid lifters have been used for last 70+ years or so. Why are they bad to use now if they have lasted this long? We have better oil so should last longer then before. Rollers are nice and last a bit longer but IMO, not needed unless for the faster rev up or because you have $$ to spend on the bragging rights. I have solid lifters in my 462 and will be starting her in a few weeks.

[Ont67shortbox]

The biggest problem with solid lifters is todays oil doesn't have the zinc and phos. in it like the oil of old.I used Valvoline VR1 race oil as it does have the required z&p,there are additives that you can buy as well.If you run it on regular oil with low z&p plan on replacing the lifters,wearing the lobes off and redoing your whole build to get the shavings out of your bearings.

[BossHogg69]

I uset the VR-1 Valvoline already, and planned on continuing that. I'm not against solid lifters, but I already have two different hydraulic cams... I would've loved to have a roller, but like Ripdog said, I'm not in it for braggin rights, and I don't have an extra $1000 lying around...

[Jim_PA]

Originally Posted by Ont67shortbox

The biggest problem with solid lifters is todays oil doesn't have the zinc and phos. in it like the oil of old.I used Valvoline VR1 race oil as it does have the required z&p,there are additives that you can buy as well.If you run it on regular oil with low z&p plan on replacing the lifters,wearing the lobes off and redoing your whole build to get the shavings out of your bearings.

Hydraulic flat lifters supposedly suffer from the same problem, although, I've been using straight Mobil 1 Syn. 10-30 for 2-3 years with no problems.

[Ont67shortbox]

Originally Posted by BossHogg69

I uset the VR-1 Valvoline already, and planned on continuing that. I'm not against solid lifters, but I already have two different hydraulic cams... I would've loved to have a roller, but like Ripdog said, I'm not in it for braggin rights, and I don't have an extra $1000 lying around...

Thats exactly why I went with solid,more rev capabilities than hydraulic,and half the price of a roller.Maybe on the next build (3-4 yrs) I will go with a 496 and roller, but this works great for now.

[drag_72]

use rotella oil heavy duty. then ad the additives