[Adam854]

Hello everyone, I made a post concerning my 350 sbc setup a week ago, since then I have learned a lot more and have done a lot more research. I have altered my planned setup a bit and would like your input on it.

The car this motors in is a 1981 z28 Camaro with a 4 speed manual. The engine is a pre 1986 SBC 350 goodwrench crate engine here are some specs on it
8:1 CR
4.00 in bore
3.48 in stroke
76cc stock heads
Stock cam 3.90 intake/ 4.10 exhaust lift; 195 intake/ 202 exhaust duration at .050
1.94 intake valves and 1.50 exhaust valves
4 bolt mains
2 piece rear main seal

Here are a list of modifications that have already been done to the motor by the previous owner
600 CFM Edelbrock performer carb
Weiland dual plane intake
Moroso Hei distributor
patriot 1 5/8 full length headers

This car is not drove a whole lot, My main goal for it is to make as much HP as i can on a budget. I would be really happy if i could get around the 400HP mark. I would like to keep the spending under 2k for this project. Here is my plan
Get some Brodix ik 180 heads
specs: 64cc chamber, 180cc intake runner, 2.02 intake/ 1.600 exhaust valve, 0.525 max lift, 1.250 outside diameter of outer valve spring

Get a Comp cam XE268H
specs: 0.477 int./0.480 exh. lift, 224 int./230 exh. duration at .050

Comp cam dlc lifters
1.5:1 roller rockers
and 0.28 head gaskets
This setup should get me around 9.3:1 CR

I guess my main concern is the flat tappet cam, I know that I should go with a roller cam setup but again, I am trying to keep this on a budget. I guess my main question is 1. does this setup look like it will deliver a good boost in power? And 2. will the 1.250 valve springs work well with the flat tappet cam? I was thinking of putting on 1.6:1 rockers for a little more lift, but would they put too much strain on the valve train and wipe out my cam? The heads have a max lift of 0.525 and the cam delivers 0.477 int./0.480 exh. So i would think that I am safe, but how much lift is too much for a flat tappet?

 

[BogiesAnnex1]

Heads make this engine! Your choice is a great improvement.

The Comp XE268H with DLC lifters is a good answer to modern day flat tappet wear issues.

The Edelbrock 600 CFM is too small to feed 400 or above hp with the parts your proposing this about a 380 maybe 390 hp engine which will hit under 5800 RPM with about an equal amount of torque around 4700.

Same to be said for the 1-5/8ths headers for the 350 these are too small to support over 400; horses.

Getting a 350 with your combination to go over 390 hp takes a lot of attention to the details. Your substituting fine engineering for displacement and or a lot more cam and intake.

Bogie

 

[Fstarocka]

I had a GM engine i rebuilt 2 yrs ago for a rental boat.. wiped 2 lobes in 2 hours despite break in oil additives etc.. i took another set of 8 lifters from the same box sealed power, heated the ends up with a propane torch till they were kinda yellow (350-450?) and oil dipped em and they turned a purple color. Of course i was peeved and didnt even change the cam, Same engine, same cam ALL i changed was the lifters i "doctored" -

Motor still running great 1 year later - this is how they looked afterwards:

 

[ericnova72]

Couple of things I would do....

Take the stock valve springs off your old heads, put them on the Brodix head and remove any shims below the hard spring seat or spring cup that comes on the Brodix head.....you want the stock spring set up as loose and light pressure as it can be.
This will help with your chances on cam break-in.
Just don't go revving on it above 4500 rpm until the cam is set and you've changed back to the good springs.

Same with the rocker arms...use your stock 1.5's off the old heads to ease open spring pressure during break-in.

It's not high lift per se that is the problem....it is the higher spring pressure that results from compressing the spring more at that higher lift that does the damage.

After you get the cam broke in, then put the Brodix springs back in, and add the 1.6 rockers if you wish.
Best combo is likely to be a split ratio set of rockers, with 1.6 on the intakes and 1.5's on the exhaust.
You can buy them as split sets.
It's harder to get the naturally aspirated intake fuel charge in, than it is to get high pressure exhaust out is the reason for the split set.

A tip during assembly....put the cam in with just the cam gear on but no timing chain yet, put all the lubed lifters in place.....then rotate the cam by hand while paying attention to the lifters - you want to make dang sure all the lifters are rotating in their bores as the cam is turned by hand.
If it helps you, put a paint pen dot on the rim of each lifter so it's rotation is more easily noticed.
If you've got some that turn well, and others that barely turn.... then swap them around a bit....try to get them all turning a similar amount.

Good call on the .026- .028" head gasket thickness 👍 .
Here is a source if you don't already have one.
Mahle Original, Head Gasket, Chev SB, 4.100" Bore, .026" Compressed, Each - Competition Products

 

[Adam854]

The Comp XE268H with DLC lifters is a good answer to modern day flat tappet wear issues.

That’s what I was hoping. It doesn’t say on the summit website but are these comp cams dlc lifters hydraulic or solid? What would the difference be between the two?

 

[Eduramac]

That’s what I was hoping. It doesn’t say on the summit website but are these comp cams dlc lifters hydraulic or solid? What would the difference be between the two?

The Dlc lifters are known as like coating. Supposed to be much harder lifter foot.

 

[ericnova72]

That’s what I was hoping. It doesn’t say on the summit website but are these comp cams dlc lifters hydraulic or solid? What would the difference be between the two?

The DLC coated lifters are only available in hydraulic flat tappet at the current time.
i don't know if Comp plans to also do the mechanical (solid) flat tappet lifters.

 

[Eduramac]

Hello everyone, I made a post concerning my 350 sbc setup a week ago, since then I have learned a lot more and have done a lot more research. I have altered my planned setup a bit and would like your input on it.

The car this motors in is a 1981 z28 Camaro with a 4 speed manual. The engine is a pre 1986 SBC 350 goodwrench crate engine here are some specs on it
8:1 CR
4.00 in bore
3.48 in stroke
76cc stock heads
Stock cam 3.90 intake/ 4.10 exhaust lift; 195 intake/ 202 exhaust duration at .050
1.94 intake valves and 1.50 exhaust valves
4 bolt mains
2 piece rear main seal

Here are a list of modifications that have already been done to the motor by the previous owner
600 CFM Edelbrock performer carb
Weiland dual plane intake
Moroso Hei distributor
patriot 1 5/8 full length headers

This car is not drove a whole lot, My main goal for it is to make as much HP as i can on a budget. I would be really happy if i could get around the 400HP mark. I would like to keep the spending under 2k for this project. Here is my plan
Get some Brodix ik 180 heads
specs: 64cc chamber, 180cc intake runner, 2.02 intake/ 1.600 exhaust valve, 0.525 max lift, 1.250 outside diameter of outer valve spring

Get a Comp cam XE268H
specs: 0.477 int./0.480 exh. lift, 224 int./230 exh. duration at .050

Comp cam dlc lifters
1.5:1 roller rockers
and 0.28 head gaskets
This setup should get me around 9.3:1 CR

I guess my main concern is the flat tappet cam, I know that I should go with a roller cam setup but again, I am trying to keep this on a budget. I guess my main question is 1. does this setup look like it will deliver a good boost in power? And 2. will the 1.250 valve springs work well with the flat tappet cam? I was thinking of putting on 1.6:1 rockers for a little more lift, but would they put too much strain on the valve train and wipe out my cam? The heads have a max lift of 0.525 and the cam delivers 0.477 int./0.480 exh. So i would think that I am safe, but how much lift is too much for a flat tappet?

Hello everyone, I made a post concerning my 350 sbc setup a week ago, since then I have learned a lot more and have done a lot more research. I have altered my planned setup a bit and would like your input on it.

The car this motors in is a 1981 z28 Camaro with a 4 speed manual. The engine is a pre 1986 SBC 350 goodwrench crate engine here are some specs on it
8:1 CR
4.00 in bore
3.48 in stroke
76cc stock heads
Stock cam 3.90 intake/ 4.10 exhaust lift; 195 intake/ 202 exhaust duration at .050
1.94 intake valves and 1.50 exhaust valves
4 bolt mains
2 piece rear main seal

Here are a list of modifications that have already been done to the motor by the previous owner
600 CFM Edelbrock performer carb
Weiland dual plane intake
Moroso Hei distributor
patriot 1 5/8 full length headers

This car is not drove a whole lot, My main goal for it is to make as much HP as i can on a budget. I would be really happy if i could get around the 400HP mark. I would like to keep the spending under 2k for this project. Here is my plan
Get some Brodix ik 180 heads
specs: 64cc chamber, 180cc intake runner, 2.02 intake/ 1.600 exhaust valve, 0.525 max lift, 1.250 outside diameter of outer valve spring

Get a Comp cam XE268H
specs: 0.477 int./0.480 exh. lift, 224 int./230 exh. duration at .050

Comp cam dlc lifters
1.5:1 roller rockers
and 0.28 head gaskets
This setup should get me around 9.3:1 CR

I guess my main concern is the flat tappet cam, I know that I should go with a roller cam setup but again, I am trying to keep this on a budget. I guess my main question is 1. does this setup look like it will deliver a good boost in power? And 2. will the 1.250 valve springs work well with the flat tappet cam? I was thinking of putting on 1.6:1 rockers for a little more lift, but would they put too much strain on the valve train and wipe out my cam? The heads have a max lift of 0.525 and the cam delivers 0.477 int./0.480 exh. So i would think that I am safe, but how much lift is too much for a flat tappet?

How far down are the pistons in the hole what is the piston top flat or 4 valve reliefs.

 

[Eduramac]

The Dlc lifters are known as like coating. Supposed to be much harder lifter foot.

Diamond like coating.

 

[Adam854]

How far down are the pistons in the hole what is the piston top flat or 4 valve reliefs.

It has dished pistons with four valve reliefs, I believe the pistons are 0.020 below the deck. I know the right way to do this project would be to zero deck the block, put in flat top pistons and go from there. However I am trying to do this on a budget, and I want to try to avoid pulling the motor out. In all honesty if I can just get a true 380-400hp I would be really happy with that!

 

[Adam854]

Same with the rocker arms...use your stock 1.5's off the old heads to ease open spring pressure during break-in.

Will the stock rocker arms fit properly with the bigger valves? Also would I use my stock pushrods with them just for break in? It sounds like a really good idea, I want to be sure it will all fit properly for break in.

 

[ericnova72]

The bigger diameter valves don't effect rocker arm fit, but the bigger valve diameter means you will need to test fit the head and do a valve-to-piston clearance check.
it may require the pistons needing a flycut for intake valve clearance due to lack of any existing valve relief in the piston, combined with bigger cam and larger valve diameter.

You can use the stock rocker arms for cam break-in.

You CANNOT use the stock pushrods....the aluminum heads have hardened steel pushrod guideplates.....they will eat the stock unhardened pushrods.
The pushrods will need to be hardened for use with guideplates

 

[Moosecountry]

I chose the same camshaft for my nephew to install in his sons 385 in a 4x4. It runs well but I doubt it has 340 hp? I seem to see smaller numbers than many hotrodders here. EG: I had a car running 11.9s @ 3560 me inside, mathematically was 400 hp based on et/weight

 

[BogiesAnnex1]

Will the stock rocker arms fit properly with the bigger valves? Also would I use my stock pushrods with them just for break in? It sounds like a really good idea, I want to be sure it will all fit properly for break in.

No on stock pushrods for several reasons:

1. Aftermarket aluminum heads move the valve spring base .1 inch higher than stock. This requires a valve with a .1 inch longer stem length and a push rod at least that much longer than stock. Keep in mind that the aftermarket moved the spring cup up .1 inch to accommodate a thicker head gasket deck and usually a deeper valve pocket. All this means is the stock valve spring and rocker stud boss are a higher distance from the gasket deck but are otherwise dimensionally the same for the spring length, rocker position and the length of stem exposed above the top of its guide.

So a flat tappet SBC uses 7.8 inch long push rod but with aftermarket aluminum heads you would start with 7.9 inch push rod. Where you’re using a factory or OEM roller cam and lifters these stock use a 7.2 inch push rod but if you use an aftermarket aluminum head this then needs a 7.3 long push rod.

2. The type of rocker guidance whether push rod in steel guide or self-guiding to the valve stem rocker takes a different push rod. Where the push rod is guiding using a steel guide that fastens under the rocker stud hex or if running old time heads with a cast in guide the push rod has to be the hardened type. Another caution here is some hardened pushrods are only so on one half so you need to be sure of what type of hardening was done so that if a half length that end is kept up toward the rocker.

Where a self-guiding rocker is used it doesn’t matter if the push rod is hardened or where or if. With self guiding rockers a push rod guide is not used. In the case of a sheet metal guide it is just not used in the case of a cast in iron head guide it is drilled out.

When using high lift cams call that at .5 and higher pushrod clearance to guides of any type must be checked for clearance the entire lift cycle, included in this is pass hole clearance where the push rod passes through the head casting to get to the rocker box. Same is said for rocker to valve spring and stud slot to stud clearance. The further the cam timing and lift gets from GM production values the more critical this gets.

Keep in mind that the Gen 2 LT1 and LT4 as well as engines from Gen 3 up are often seen with sheet metal push rod guides and self guiding rockers, where you encounter this these guides are a loose fitting assembly aid that help speed fitting the push rods and rockers but otherwise have no push rod alignment function.

Bogie

 

[BogiesAnnex1]

I chose the same camshaft for my nephew to install in his sons 385 in a 4x4. It runs well but I doubt it has 340 hp? I seem to see smaller numbers than many hotrodders here. EG: I had a car running 11.9s @ 3560 me inside, mathematically was 400 hp based on et/weight

Depends a lot on engine size, your supporting cast, also, where you live.

A 385 is 10 percent bigger than a 350 so it would need 10% more timing principally in the .050 area and will benefit with more lift if the head flow supports any useful rate of and in total increased flow at higher lifts.

Cams this “mild” require the supporting cast be very precisely executed.


Where you live counts a lot my sighted numbers are on the Pacific Coast at sea level, at lower temps so except for humidity which ranges far and wide day to day depending on the weather, but where I live takes out a lot of the needed adjustment fudge factors to compute torque and power to the ideal SAE test perimeter as two out of three are eliminated by nature. So if you live where its hot that being above 60F, humid or has some altitude your real power will be under what is received at SAE rest conditions.

Bogie

 

[Moosecountry]

Bogie, the 385 lives in a place Im sure you know? Osoyoos BC. The kid is 19, 3/4 tonne GM, I also chose 750 edelbrock and RPM intake? The heads are lesser 350 vortec heads. He wanted a hydraulic cam and simple. it has long tube headers

 

[BogiesAnnex1]

Yes I do, have friends in Republic, Wa. and have fatisized about opening a shop in Meteline Falls a bit farther east. This desire causes a lot of trouble at home as wifey wants to move to either the Boston, Mass area or Portsmouth, NH.

Bogie

 

[MONTANA1]

Hello everyone, I made a post concerning my 350 sbc setup a week ago, since then I have learned a lot more and have done a lot more research. I have altered my planned setup a bit and would like your input on it.

The car this motors in is a 1981 z28 Camaro with a 4 speed manual. The engine is a pre 1986 SBC 350 goodwrench crate engine here are some specs on it
8:1 CR
4.00 in bore
3.48 in stroke
76cc stock heads
Stock cam 3.90 intake/ 4.10 exhaust lift; 195 intake/ 202 exhaust duration at .050
1.94 intake valves and 1.50 exhaust valves
4 bolt mains
2 piece rear main seal

Here are a list of modifications that have already been done to the motor by the previous owner
600 CFM Edelbrock performer carb
Weiland dual plane intake
Moroso Hei distributor
patriot 1 5/8 full length headers

This car is not drove a whole lot, My main goal for it is to make as much HP as i can on a budget. I would be really happy if i could get around the 400HP mark. I would like to keep the spending under 2k for this project. Here is my plan
Get some Brodix ik 180 heads
specs: 64cc chamber, 180cc intake runner, 2.02 intake/ 1.600 exhaust valve, 0.525 max lift, 1.250 outside diameter of outer valve spring

Get a Comp cam XE268H
specs: 0.477 int./0.480 exh. lift, 224 int./230 exh. duration at .050

Comp cam dlc lifters
1.5:1 roller rockers
and 0.28 head gaskets
This setup should get me around 9.3:1 CR

I guess my main concern is the flat tappet cam, I know that I should go with a roller cam setup but again, I am trying to keep this on a budget. I guess my main question is 1. does this setup look like it will deliver a good boost in power? And 2. will the 1.250 valve springs work well with the flat tappet cam? I was thinking of putting on 1.6:1 rockers for a little more lift, but would they put too much strain on the valve train and wipe out my cam? The heads have a max lift of 0.525 and the cam delivers 0.477 int./0.480 exh. So i would think that I am safe, but how much lift is too much for a flat tappet?

I have Brodix IK 180 heads, but I used LS style COMP Bee Hive springs in them, They are much easier on the valve train and can take up to .600 lift it you want. (Watch for valve to piston clearance.)

I used 1.6 Rockers also, with a 262 / 270 XE flat tappet cam with about .510 lift at the valve and 110 LSA. They worked well. It made 465 HP and 590 TQ on my 383 with about 5 lbs of boost and got 17-19 mpg.

MT

 

[Moosecountry]

montana? rwhp?
blower or turbo?

 

[Key Largo Realtor]

Hello everyone, I made a post concerning my 350 sbc setup a week ago, since then I have learned a lot more and have done a lot more research. I have altered my planned setup a bit and would like your input on it.

The car this motors in is a 1981 z28 Camaro with a 4 speed manual. The engine is a pre 1986 SBC 350 goodwrench crate engine here are some specs on it
8:1 CR
4.00 in bore
3.48 in stroke
76cc stock heads
Stock cam 3.90 intake/ 4.10 exhaust lift; 195 intake/ 202 exhaust duration at .050
1.94 intake valves and 1.50 exhaust valves
4 bolt mains
2 piece rear main seal

Here are a list of modifications that have already been done to the motor by the previous owner
600 CFM Edelbrock performer carb
Weiland dual plane intake
Moroso Hei distributor
patriot 1 5/8 full length headers

This car is not drove a whole lot, My main goal for it is to make as much HP as i can on a budget. I would be really happy if i could get around the 400HP mark. I would like to keep the spending under 2k for this project. Here is my plan
Get some Brodix ik 180 heads
specs: 64cc chamber, 180cc intake runner, 2.02 intake/ 1.600 exhaust valve, 0.525 max lift, 1.250 outside diameter of outer valve spring

Get a Comp cam XE268H
specs: 0.477 int./0.480 exh. lift, 224 int./230 exh. duration at .050

Comp cam dlc lifters
1.5:1 roller rockers
and 0.28 head gaskets
This setup should get me around 9.3:1 CR

I guess my main concern is the flat tappet cam, I know that I should go with a roller cam setup but again, I am trying to keep this on a budget. I guess my main question is 1. does this setup look like it will deliver a good boost in power? And 2. will the 1.250 valve springs work well with the flat tappet cam? I was thinking of putting on 1.6:1 rockers for a little more lift, but would they put too much strain on the valve train and wipe out my cam? The heads have a max lift of 0.525 and the cam delivers 0.477 int./0.480 exh. So i would think that I am safe, but how much lift is too much for a flat tappet?

I have over 1000 miles on my comp cam flat tappet cam, no problems. get some extra assembly lube and put it on heavy on the cam and lifters. Use the comp cam oil additive and also use it when you do oil changes. Follow the high rpm 20-30 minute break in instructions. If the motor starts getting hot, shut it down and continue when it cools off. Make sure you get the full time in. I also kept the idle a little high for the couple hundred miles of driving. Good luck with the new motor