BBC 049 Heads on 489-496 BBC with ISKY238/248 upper HYD roller cam kit
Hello all, Building a 489-496 BBC in planning stages. Will be in '68 Vette (orig 427 3x2 car) TH400 auto (will get stall to match engine) 3.70 gears. Street very little strip maybe 2-3x year. Want to run on pump gas figure 10-10.2:1 CR. Want to retian stock look of Original 427.
the build (have Isky topend kit, 454 4 bolt block, 4.25" 4340 crank, 6.385" Eagle ESP H rods, NO PISTONS yet or heads )
-ISKY 238/248 @ 0.050" 578i 608e
-ISKY 8005-A springs
---135# set pressure @ 1.875" install hieght
---400# / in.
---1.100" coil bind
-ISKY 3607-ST retainer
-ISKY VL-3/8 locks
--1 groove, 5.5mm Valve Stem
- ISKY puchrods 203-96 Minus .650
-ISKY Hyd roller lifters 3970-HYRT
-Corvette 3x2 dual plane intake 3 Holley 2 barrel carbs.
-Run Headers or Side pipes with headers.
-Have Comp cam SS full roller rockers.
Plan to go with GM 049 casting that I am assuming will need rebuild. Plan is to upgrade to 2.19i 1.88e, Home port and polish and install ISKY springs. Figure Bare castings and possible some or all guide replace ment. I do NOT know the condition of the Valve guides yet.
I am assuming I will need NEW Valves.
1) What are my options with valves stock 3/8 or 11/32 stems if some or all guides need to be replaced is it worth it to update to 11/32 stems given data above ? (I am not sure if worth it I assume new locks, and not sure what else will not work with 11/32 valve)
2) I am not sure what stock install height is of springs are on 049 heads with the Install hight of ISKY Springs 1.875" will it work ? DO I need to consider longer valves or machine heads or shims or combo ? Which is the best option. Will one or combo of options work better given I have the pushrods lengths.
3) Is thre any good calculators out there to help figure this out becuse I may have to cut the heads to get desired CR ?
4) What are good valves to consider ? What are Ferrea Valves?
5) What are the best updates to 049 heads to make POWER and FLOW?
I will be getting the heads tomorrow and will take them apart and clean up. I will take them into the Machinest and get his take (get them checked out)
This kit is nice but has me working backwards a little.
Good thing this is a winter project.
Easiest to get +.100" 3/8 stem Manley 2.19 intake valves. Stock length exhaust valve.. The exhaust side will need a rotator eliminater. I use a large 5/8" ID - thick, flat washer ( TSC gold color) and a .060" spring seat. This will give you a correct spring height to build from.
Correct way to do 2.19/1.88" Is with a Serdi type cutter. This will blend the correct angles into the chamber. A 70+ degree "Bowl Hog" will open up the bowl below the seat.
Cut heads .020". Use a short dome (.200-.250") piston Probe has an inexpensive set that works great.
Check the prices. I love to do these but, in this area the total cost, including cores, is more than a set of new aftermkt aluminum oval ports. (Ebay around $750-$800.00)
My brother eclipsed the price of assembled aluminum heads rebuilding his 049's. I priced local machine work and parts and for the first time in my 50 years of hot rodding I bought a crate motor. Could not be happier and saved money and time. JMHO.
You won't get much out of the 2.190's and 1.88's unless you work the short side radius pretty well. I did a build almost exactly as described above but used KB forged pistons and a Comp BMT cam. I took a head to a flow bench guy with a stock valve/port, a 2.90 done almost exactly as above with bowl hog/Serdi and no port work and one with my completed port. I'm not a pro in the port business but common sense goes a long way.......towards carpel/tunnel if you do it :D . Without digging out the sheet, the stock port was around 250, with valve added-270, with port work slightly over 300 and I'm not even going to the "good port bad port thing." What has been said is true. You can get some decent aluminum like Pro Comp (probably a dirty word here) cheaper than doing your heads unless you can do lots yourself. If I had to charge someone for what I did, I would try to talk them out of it. Guide and bowl hog work is time consuming and the machinist has to pay for the machine and his time. JMO, but if you want to stay with good stuff, the AFR 310's with CNC port would be killer for a fair price. (that's after carpel/tunnel surgery)
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