|04-06-2013 10:18 AM|
The closed chamber heads are 107 cc,they have 2.06 in and 1.72 ex valves.Ive owned 6 vettes of different yrs including a 68 L-72 with 3.08 gears and a 67 L-72 with 3.73s,both had factory side ex.I would keep the 3.76 stroke crank and just build a 430.The cam will dictate how much comp you can get away with as its cylinder pressure that either bleeds at low rpm with a narrow lobe separation cam or builds pressure early with a wide lobe.Duration also plays part. Go with something along the old L-88 cam as it was long on duration and not so high on lift. Plus its a solid.Hydraulics are for lazy people. If the lash is correct, it doesnt require anymore maintenance than a hydraulic,just use poly-locks.Go to this link and look at the cam specs, its a real nice street cam. Ran em a long time,no issues. If you want to really help the geometry of the rockers,use boss 302 ford rockers as they are 1.75 ratio and use a rectangle i guess you could call it rocker ball that also has an oiling groove and is flat on top.
As far as the heads,youve got the heads that will work,just port match em and do the bowls,put 1.88 ex valves in and leave th 2.06 in.Use a bronze guide,mill to get decks straight as a bbc head is usually out by .010 to .012 on the deck warpage.Use 7/16 pushrods and guide plates. I used to have alot of ex guide issues with the stock 1.7 rockers (this was before i got smart enough to do the geometry and measure for the correct pushrod length and the 1.75 cured it)
Use a cloyes true roller and leave the cam straight up.10.0 to 1 should be fine with about 34 total timing. Dont go for the high volume oil pump,not necesarry,just use a pressure pump.The factory 427 cranks are already hot rod approved. My last 427 made 521 hp at the flywheel and was driven daily making 11mpg in town and 17 on the freeway. I like a forged piston with 1/16-1/16-3/16 ring package rather than the 5/64 (read easier to obtain and more common) plus depending on how you are going to hone the cylinders,moly or cast iron rings work fine and are dependable.
No subsitute for cubic inches huh? We just won the march meet at Bakersfield and are the fastest front engine T/F car on the planet at 269.08 in the final and threw the blower belt off before the finish line and its only a 407 cu in engine.
Oops,just about forgot the link
|04-05-2013 06:45 PM|
|04-05-2013 12:28 PM|
|Sgt.Bryan||THANKS!! she ain't a show car , I drive this one.|
|04-05-2013 08:08 AM|
|spinn||My god! Look at that car.|
|04-05-2013 07:34 AM|
|AutoGear||Love the car; those pipes are great looking. Keep up with your progress on the 454; a budget friendly 454 rebuild will be a nice addition to the site.|
|04-05-2013 06:07 AM|
Thanks for the opinions and info guys. I think I am gonna leave it a 454 and use those keith black 201 pistons!
|04-04-2013 05:32 AM|
Which 454 pistons for 063 heads?? on a budget
|04-03-2013 06:49 PM|
|vinniekq2||When I freshened a 454 in my camaro(was already rebuilt,just not well)with a new cam and kit,balance,machine work to straighten block,machine heads for 2.19/1.88 valves,cost of valves,new rod bolts,chain and gaskets,I spent $1700.บบ|
|04-03-2013 04:30 PM|
Go with the 454. Ain't no substitute for cubic inches. For a cruiser it will be great. The KB201 pistons will work well on unlead premium.
I don't know what F-Bird 88's beef with ProComp BBC heads is. I've sold more than forty pairs of castings and they have all been top of the line. I like them better than several "Brand name" $$$$$ heads. For a common sense street/strip build they are the best.
Use just the ProComp oval port castings and then install Manley valves and good springs.
Up grading the iron heads can get expensive real fast. Guides and hard exhaust seats cost and then you still have to buy new valves, springs etc.
|04-03-2013 04:00 PM|
That TRW 427 piston gets it done. On a o decked block you want a 106cc head for 10:1cr.
You want the cr high enough but not too high. You must use quality 92+ octane gas in this motor.
not less than a 102cc head on this one.
the heads will need porting. The crank will need rebalanceing and the rods will need preparation.
Correct (block/crank/rods machining is essential. (there are no shortcuts)
A street friendly mechanical street roller cam works real well in this motor.
( essentually a STREET roller version of the 427-425HP L-72 cam) 244@.050")
EG Comp cams XR280R-10 11-771-8
EG Lunati VooDoo street roller #60232
or similar cam in this duration range.
What hood is on your 69 vette?
This is a failrly straightforward build but you want to work with a good machine shop/engine builder to bring it together.
It builds a very powerfull oval port head - unleaded fuel modern version of the 1969 427-425HP L72 corvette motor.
( makes a lot more power and torque and goes like hell....LOL.
"cheap" will get you stung and disapointed.
You have many of the good hard parts already.... block heads crank.
What is your location?
|04-03-2013 03:15 PM|
Thanks for the replies. Like I said, I'm a noobie here. I prob messed up on the piston dome/dish when I figured my compression... Couldn't find a definate answer for what piston I had, actually compared summit/jegs replacement pistons.... My car is originally a 69 L36 390HP 427 car, Auto, 3.08 rear end. My sidepipes are HUGE stainless sidepipes with glasspacks removed and spiral freeflowing baffel in its place.. 2 1/8" individuals to 4" collector.. Unfortunately my Vette, sounds like a 73 pickup with a low compression 454 and oversized exhaust...
Yes, the 427 crank I have is forged. Now I understand our modern fuel is different but, why is (most) everyone recommending around 9-9.5:1? Reason I ask is the L36 that this car had was 10.25:1 and I've read that quite a few people are running 10-10.5:1 in 454s. So, If I were to rebuild this motor as an original L36 390hp 427 making 10.25:1 , wouldn't that be about even with a 454 making 9:1 using the same heads, similar cam? I think JE pistons are out, they are +$600. KB pistons, part#201 seem about right price wise and use thinner rings. But higher compression than advised here. Keith Black KB Performance Pistons KB201-030 - SummitRacing.com
These are the 427 pistons I was looking at using, just stock replacements.
Speed-Pro Forged Pistons ZL2300NF - SummitRacing.com
The only reason I want to keep my heads, is well, I already have them.. They just need rebuilt. New heads are out of the budget right now, and I would like to stay with an oval port setup as I'm not looking for huge numbers. If I spend $2000 on new heads, I might as well call up vortecpro and get a crate motor...... I was already thinking about larger valves to help it breath a little better though.
I understand there is no replacement for displacement but just looking for best bang for the buck...Teach me, I'm here to learn.
|04-03-2013 11:53 AM|
Not sure how you figured 8.4:1, unless the pistons are deeply dished. KB202 flat top with a 3cc valve eyebrow will make 9.317:1 SCR when used with 101cc heads.
KB Pistons for Automotive Applications
Most any of the special pistons with a small pop-up to work with the closed chamber heads will make too much SCR for pump gas. Here's the SRP offering with a 14cc dome...
BIG BLOCK CHEVY - CLOSED CHAMBER - SMALL DOME PROFILE - JE Pistons
In my opinion, the 3cc pistons mated with a cam that closes the intake valve at somewhere around 35 degrees ABDC would make a DCR of ~8.236:1 that should run well on pump gas and make good power without detonation. I don't like recommending flat tappet cams, but will show you an example of what I might use as far as cam timing.....
Excellent midrange torque and HP,good idle, daily usage and offroad, towing, performance and fuel efficiency, good w/smallplate nitrous system, 2600-3000 cruise RPM, 8.75 to 10.5 compression ratio advised.
Good w/centrifugal or small Roots supercharger, 8lbs. maximum boost w/8.5:1 maximum compression ratio advised.
|04-03-2013 09:40 AM|
Do not buy pro comp heads. If you want to buy junk heads you don't need our help. You can screw this up fine by yourself.
building with the 427 crank will cost about the same as the 4" crank. Both are more than capable.
is that a forged 427 crankshaft?
450-500hp is easy with that combo. Heads will need a work up. (porting+ big valves)
The chambers will be a bit bigger once all done.
Pistons KB or Probe or Wiesco. With a small dome (depends on the engine you are building)
the factory side pipes are actually quite restrictive.
Basicly you want to build a updated modern (ported) oval port head version of the 427-425hp L72 .. 454-450HP LS6 motor.
Think 10:1cr, street roller cam Ported oval ports RPM manifold 850-950cfm holley. Headers free flow exhaust. 500++ hp 92 octane
is this a 4 speed or a auto trans car? Gear ratio?
Those heads will flow 300+cfm when done right.
But if you are going to start with a aluminum head DO NOT BUY JUNK.
|04-03-2013 08:59 AM|
|vinniekq2||those heads flow around 230 plus CFM. Just buy a good set of heads for the car. look for 9.3 ish CR depending on the cam you choose.The car deserves a decent engine,imo|
|04-03-2013 08:40 AM|
Which 454 pistons for 063 heads on a budget
Hey Fellas, noobie here with a couple questions.
Well I have a 69 vette that used to be an original 427 car but, now has a 73 truck 454 with flattops (289 block). fortunately it still has the closedport 063 390HP heads, but still only brings compression up to about 8.4-1 . The motor needs freshened badly, so I am wanting to rebuild her... Honestly with the beautiful stainless sidepipes I have on her, she shouldn't sound like a low compression *truck* motor.....*tear*
So, my question is with my 101.9cc 063 heads, what would be a good 454 piston to use? I am looking for more compression but I'm lost when it comes to looking for a closed port piston for a 454 . Looking for 400-500hp limit, not building a race motor or trying to pull out tree stumps, just a nice bbc that I can have fun with on the street.
I have a 427 crank also. Pistons for that seem very resonably priced and would give me the power I want.. Would this be a cheaper route?
Last thing, my heads will likely need rebuilt, including seats (bad popping on left side idle). Would it cost me as much as a new set of heads, like procomps?
Thanks for any information or opinions!