300 hp N/A carb 2.8 V6 engine

[veekuusi]

This thread is a continuation of this thread:

http://60degreev6.com/forum/showthread.php/49098-roller-lifters-with-2-8

This story is to get a winning engine to a historic race car.
GM 2.8 V6 push rod engine in a 1974 Ford Capri.

-block 1996 3.1 (gen 3)FWD bore 89.25 , stroke 76 mm
-3400 aluminum heads (gen 3)
-custom billet Crower
-pistons Diamond custom
-Total Seal piston rings
-Manley stainless steel valves 1.76" / 1.42"
-camshaft Schneider 258/264 (.050") , lobe separation 106 , valve lift 13.2 mm (0.520")
-mechanical roller lifters (Crane)
-double custom valve springs closed 175 lbs, open 445 lbs
-roller rockers (Crane) 1.6:1
-custom push rods (Comp Cams)
-compression ratio 12:1
-Scat connecting rods 5.700"
-custom intake
-2 Weber 45 mm carbs
-ignition 6 x 034 Motorsport coils
-ECU Gems EM36
-spark plugs NGK BCR8ES
-custom exhaust 38 mm ID 3-> 1
-ATI damper
-electic water pump Davies Craig (EWP 115)
-dry sump AT-Power (3 stage)
-bellhousing Chevy S-10 5-speed (82-92)
-2 disc Alcon clutch
-gearbox 5-speed "dog box" Sellholm M47000

A had a total engine loss bacause of crankshaft cracked june 2014 (first race in this season).
Pretty much damage.
The race season 2014 was over.

I have in my garage all the other parts for the new engine except one.
The crankshaft.
The old one was original cast crank.
I ordered a new billet crankshaft from Crower.
I have not yet seen it ,
the latest news is that it should be ready "mid October".

There has been lots of enquirys, what is going on with this project.
I am sorry to put no input here in this forum.
But hopefully I have now time and motivation to go on ,
and we can see a better and winning engine in my car the race season 2015.

[SappySE107]

Have you ported the new heads? Would you like the best possible port work done to them? Its kind of a big deal on what you do to those heads and we have the most experience in the gen 3 heads as far as testing goes. Also, why aren't you running the cam we designed for your engine, or have you and it didn't work out as well? Would love some feedback on that as we have a great success rate with designing camshafts per specific app and if that was not the case for a solid valvetrain, it would help us to learn from it.

[veekuusi]

Have you ported the new heads? Would you like the best possible port work done to them? Its kind of a big deal on what you do to those heads and we have the most experience in the gen 3 heads as far as testing goes. Also, why aren't you running the cam we designed for your engine, or have you and it didn't work out as well? Would love some feedback on that as we have a great success rate with designing camshafts per specific app and if that was not the case for a solid valvetrain, it would help us to learn from it.

I have been running just one camshaft so far.
It is a Schnaider custom cam with LSA 106.
The one I got from you has LSA 113.5.
The reason for not running your cam is that the LSA in your cam has too big LSA for a N/A carb engine.
Wider LSA works fine with boosted and/or fuel injected engines.

I have not yet ported 3400 heads.
I have had difficulties drilling the stud helicoils (for 7/16 ARP studs).
Allready destryed one 3400 head.
Maybe if you throw me with a reasonable offer , we could make a deal.
What do you think, have you possibility to make the helicoils for 7/16 rocker studs?
It is safer first to do the helicoils , and if that works fine, then do porting job.

[ForcedFirebird]

The one I got from you has LSA 113.5.
The reason for not running your cam is that the LSA in your cam has too big LSA for a N/A carb engine.
Wider LSA works fine with boosted and/or fuel injected engines.

You have that backwards. Narrow LSA is (supposed to be) good for boosted engines to keep from bleeding off pressure. Wide LSA is good for higher compression N/A motors.

[3400-95-Modified]

Info on LSA... I can see what Forced means... Idle vacuum is decreased with narrower LSA, that doesn't sound beneficial for a Carb'd setup.

A CHP magazine article comparing identical camshafts except for the LSA (along with comparing open vs. split plenum intakes): Camshaft Lobe Separation Angle Performance Test Narrower LSA:

A narrower LSA will increase overlap. This has a tendency to reduce engine output at lower RPM and increase engine output at higher RPM. A narrower LSA tend to make more peak power but a little less average power.

Moves torque to lower RPM
Increases maximum torque
Narrow power band
Builds higher cylinder pressure
Increase chance of engine knock
Increase cranking compression
Increase effective compression
Idle vacuum is reduced
Idle quality suffers
Valve overlap Increases
Natural EGR effect increases
Decreases piston-to-valve clearance

Wider LSA:

A wider LSA tend to make less peak power, but a broader powerband. Changing the LSA also changes the valve timing events; opening the exhaust valve sooner and closing the intake valve later, both of which affect how the engine ingests air.

Raise torque to higher RPM
Reduces maximum torque
Broadens power band
Reduce maximum cylinder pressure
Decrease chance of engine knock
Decrease cranking compression
Decrease effective compression
Idle vacuum is increased
Idle quality improves
Valve overlap decreases
Natural EGR effect is reduced
Increases piston-to-valve clearance

[ForcedFirebird]

There's more to it than just that. You have to take in account ramp rates on the lobes, total duration, duration at xx lift etc. A cam should never be selected just because "I feel the LSA is too much" when in reality the 113LSA cam might actually have more overlap than the 109. Just like when people say "I have a 272 cam" when that really doesn't mean much. When we design cams, we have a huge selection of lobes where two cams may look identical in lift, duration and LSA, but perform very different.

[veekuusi]

Here we go again.

3100 block from 1996 Chevrolet Lumina.
New cam bearings, line honed,cylinders bored (with a torque plate) and decks straighened.









I use 4 old pistons and 2 new (to replace the distryed ones)..
Valve reliefs have to be made to the new pistons.
Thay came from Diamond.
It seems to be impossible for Diamond to make such pistons that a customer wants.
This was the second time it did not happen.
The gap under the dome was supposed to be 1" (1.54 mm).
It is 27.74 mm.
Well, it means the new 2 pistons are some 2 grams lighter than the old ones.
Okay, I can live with that.







And 2 new Scat SBC connecting rods (I use 4 old ones).

[1QUICKHATCH]

Looks good! How long do you have before racing starts again?

[veekuusi]

Looks good! How long do you have before racing starts again?

Well, the race season in my country is a little bit shorter than lets say
Nascar and Drag Racing seasons in USA.
Winter time here is long, you know.
But it starts some time in may or june 2015.
So, no hurry in my project.
Yet.

[Guest]

You have that backwards. Narrow LSA is (supposed to be) good for boosted engines to keep from bleeding off pressure. Wide LSA is good for higher compression N/A motors.

In all my years of being around engine builders and winning engines that make LOTS more power than just about any of our 60 degree V6s will ever make, they would ALL say you have it backwards.

While you don't want the LSA to be too close, because that will cause other issues, the overlap helps get the velocity up of the air flow through the engine, using the exhaust scavenging effect that a good set of headers, that would be paired with this, will provide.

A wider LSA is good for boosted engines so that the pressurized air and fuel that is being forced into the cylinder(s) is not bled off and passed right to the exhaust system where it won't really do any good ("spool up" devices would say otherwise though. lol). The sooner the exhaust can close, blocking that "espace route" if you will for the incoming charge the more of it will remain in the engine and be used to produce power.

[veekuusi]

"We are just a bit behind, your crank is at nitride now. Should get balanced and shipped next week. Sorry for the delay."

This is the message I got yesterday from Crower.
Hopefully the billet crank is coming before christmas.

Nothing much has happened with this project in a while,
but maybe I get a motivation boost now.

[1988GTU]

wtf, that is taking them forever!

[3400-95-Modified]

Two months for a custom crank... well I don't know if that is too long... depends on how much information they had on the crank itself and if they had a program to mill it yet.

[veekuusi]

Two months for a custom crank... well I don't know if that is too long... depends on how much information they had on the crank itself and if they had a program to mill it yet.

4-5 months.
They needed a sample, so they had not done anything like that before.
A sample, a stock 2.8 crank was at Crower August 1, 2014.

But I have not yet seen any crank, lets hope everything goes well.

[Guest]

I would be more than elated if I saw a custom one off crank in less than a year for such a niche engine.

There's very few of us that look at these 60 degree V6s and think "performance", most people think "Economy engine" or "junk".