Wow, I didn’t think this discussion was going to get so heated. Thanx for the input anyway. Right or wrong I have made a choice/decision. This cam is only a little bigger duration from what was in the car before. Adv.dur.256/262 dur.@.050 213/219 lift .515/.530 lsa 112. With that cam in the car it only pinged when I was trying to make it ping. Going up a hill in 4th gear, riding the brake at 45 mph and then apply WOT. It would then ping a little and you had to listen for it.

This new cam shouldn’t cause a problem with the pinging. But I guess we will see in the spring when I am able to drive it. Also I will be driving at 65mph (110kmh) at about 3200rpm, which is what I cruise at on the hiway. Considering a 5 speed in the future.

Cheers,

Shmoky

 

I am offering to help him tune it even if he buys the weenie cam we all don't like and advise against.
No one here has ever used my tuning method. I have enough confidence in it that 10.3:1 doesn't scare me one bit.

 

Thanx for the tuning offer Gruber. But Florida is an awfull long ways away LOL. I will ask for advice when the time comes. (fyi: the c.r. has been recalcuated to 10.1:1 by the engine builder)

shmoky

 

That will help a lot. Said my peace, I'm out of here. Hope it works out great!

 

Do you like the 268 in your 454 with your 3.08s ?

 

Morning Mouse...going on around 3,000 miles on the rebuild n so far I'm very pleased........Jerrylee///

 

Morning- after you get the 3.70s in you most likely will want a little more cam.

 

Here are the specs on your cam. You probaly will want to bump up one or two sizes with the 3.70 gear. this is a flat tappet cam. Shmoky is going roller.

Good for street machines, slightly rough idle, stock converter.

Operating Range: 1600-5800 RPM
Duration Advertised: 268° Intake / 280° Exhaust
Duration @ .050'' Lift: 224° Intake / 230° Exhaust
Valve Lift w/1.7 Rockers: .515'' Intake / .520'' Exhaust
Lobe Separation Angle: 110°

 

Thanx for the advice......Has anyone saw the THUMPA N MOTHER THUMPA cams by comp......What do you think...To radicle or not........Thanx again...Jerrylee///

 

All they do is shrink the LSA to around 107 to give more overlap. Don't see a performance plus just the rumble. In a street engine for a nice flat torque curve I would rather see a 112 LSA.

 

Would u guys recomend a few...Thanx...Jerrylee///

 

If you want to go hydraulic roller this one I posted earlier might be a good choice.
http://www.holley.com/50268.asp

 

Interesting thoughts, and a response

The previous builder of his engine chose the flat tappet route, but mustn't have had a valvespring scale, because it wiped a few lobes in a few miles. His open pressure was in the low to mid 300# range, far too much for any flat tappet cam life on the highway, and way too much for a successful break in. (I think we can agree, that with one of the highest rocker arm ratios and the smallest lifter, BBC's are the hardest engine on flat tappet cams and lifters) The poster wanted a bit more power, and a reliable, maintenance free engine. The hyd roller cam is right up his alley, and the added lift with slightly more duration should do it's best to give him what he wants.

On your second note, with GM putting tiny hyd roller cams in their 7.4L and 8.1L engines, with minimal duration, what were they thinking?

His compression and mild cam will give him excellent torque and fuel mileage, plus killer off the line accelleration, despite the mild 3.7 gearing and high first gear of his manual transmission.

 

Fact:
The engine functioned well with a smaller flat tappet cam (no pinging), his elevation is approximately 2000', and I'm not about to start milling the domes off his several hundred dollar pistons just to satisfy a silly DCR program. Compression equals efficiency and torque, that's why the newer engine designs have high compression, but also use small cams and EFI to allow 87 octane but still provide big torque numbers so the vehicle has good performance while at highway speed in overdrive.
I know what will work and what won't. I have one certain person that I deal with at Comp, he was recommended by several major people whom I have talked with and had E mail discussions, and he is extremely knowledgeable. Everything he's ground for me has worked well, he even found a couple of tenths for my small block combo. (10.7's in a 3500# Camaro) I agree that just picking up the phone to talk to a cam company is taking your life in your hands. When the OP first talked to me, I spec'd out the XE268HR, but ground on 112, but when the car specs were sent to my guy from Comp, who could have stepped up a bunch in duration, came up with something very similar but with more lift. 268/276 adv, 218/224 @ .050", .605/.600 lift, ground on a 113 + 4 L/C. These are their XFI lobes.

I'm sorry, but the big sloppy 230+ duration cams you like don't fit all the OP's requirements. If we were building a race car, then you bet! This is a car that will spend the bulk of it's life on the highway. As he mentions later, a 5 speed may be in the works later on. I would like to see either overdrive, or a 3.08 gear and a Richmond 5 speed with a nice low first gear, like a high 3 series to low 4 series first, along with a 1-1 fifth, for a "best of all worlds" combination. After I saw this thread early this morning, I decided to check the DCR for the heck of it. FWIW, it's 8.18:1, guess I got lucky.

 

To those who supported the OP's decision, and listened to the facts, thanks. The poor guy's been sweating the decision for a few weeks now, time to put his nerves to rest. The car will be a performer.
Yes, I am his engine builder.

 

1. The old flat tappet cam had much lower lift. This roller will open the valve further, filling the cylinder more and raise the VE a lot along with the DCR. It will be much more suseptible to detonation.
2. The newer engine designs use EFI, Antiknock sensors and back the timing off with the computer if denonation issues arise. These engines will function with specs that will destroy a carbed engine with no computer.
3. A 230+ @ .050 duration cam is not a big, sloppy cam in a 10.1 to 1 454.
4. 8.18 to 1 DCR is too high for iron heads in my opinion. 7.5 is safe 8.0 is boarderline.
5. A 3.70 gear will handle a lot more cam and be very streetable. The cam I mentioned with it's 114 LSA would give you a decent idle and flat torque curve.
6. You are leaving a lot of streetable power on the table with a 218 @ .050 duration cam in a 10.1 to 1 454 with 3.70 rear and a 4 speed.
7. Ignore the silly DCR program if that is what you are comfortable with. I think it is a valuable tool in the design of an engine.
8. I would think rather than mill the pistons to get optimal DCR you would bump the duration.
9. The 69 427 390 hp engine is an iron head, 10.25 to 1 engine. The published GM cam specs are .461 and .480 lift and 350 352 duration. (I know the ramp rates are different) This is when 101 octane leaded fuel was available.
10. Do what you want I was just trying to help.

 

Really nice cam, valve lift will be easy on the springs,
enough duration to give a 454 some mid range
punch but still mild enough for solid low end torque.

 

The OP said he had stock heads. With high lift valve spring fatigue on a stock length valve is an issue. The original lift is.480 I thought you could get by with the .575 lift and use the extra duration to get your flow and meet the DCR needs of the motor. If durability is an issue it seems like a better choice. The OP also stated 10.3 to 1 compression. If the DCR is 8.18 with the newly discovered 10.1 to 1, what would it be at the originally posted 10.3 to 1. It will definetly need 93 octane and perfect tune, quench and cooling system probably with retarded timing =(detuned), to run on pump gas. I am done.................Again.

 

I'm hoping Jerrylee takes a serious look at that cam with his
3.70s plan if he wants to go to the expense of a roller cam,
overall a nice looking cam.
The original poster has made his decision on a cam may already have
it in hand not trying to convince him.