Tunnel rammed 23* 421sbc

[F-BIRD'88]

The cam duration is 20 deg too short for max power on this engine.. It will run with your cam but you are leaving a lot on the table. Tunnel Rammed engines like to eat. Let it eat.

Use 100 octane unleaded . It will go faster and last longer too..

[Steve K]

I have a very similar TR 427 in my 5 speed 79 Camaro. Smaller heads (AFR 210's) but bigger cam (SKU 12-863-9) 263/272 SR. Compression is in the 11:1 range. Runs great on 91 oct made over 600 hp on the engine dyno. Great engine, I drive it daily when weather allows.

[54chevkiwi]

Oh yea, yours is absolutely a setup ive Paid attention to!

[mt-engines]

The cam duration is 20 deg too short for max power on this engine.. It will run with your cam but you are leaving a lot on the table. Tunnel Rammed engines like to eat. Let it eat.

Use 100 octane unleaded . It will go faster and last longer too..

Ha has a tunnel ram. The smaller cam will make more torque everywhere, and the tunnel ram will allow it to rpm more than a single plane..

My advice... STFU about 100 octane gas. Leave the 60s behind you. His combo should make mid to high 600s and be a fun weekend cruiser.

[F-BIRD'88]

The cam duration is 20 deg too short for max power on this engine.. It will run with your cam but you are leaving a lot on the table. Tunnel Rammed engines like to eat. Let it eat.

Use 100 octane unleaded . It will go faster and last longer too..

Ha has a tunnel ram. The smaller cam will make more torque everywhere, and the tunnel ram will allow it to rpm more than a single plane..

My advice... STFU about 100 octane gas. Leave the 60s behind you. His combo should make mid to high 600s and be a fun weekend cruiser.

Keep you "advice" to yourself. Or take a bit of it.
High torque equals high cylinder pressure.
Wants octane to protect an expensive 11.5:1 cr engine from detonation on the street where operating conditions change a lot..

[Steve K]

Oh yea, yours is absolutely a setup ive Paid attention to!

if you're referring to my set up, it gets 22 imperial mpg (20 us gals per mile) at 70 mph. Also has good passing power, lol

[steve cowan]

Burns spec’d tri-y headers 1-3/4 10.5” stepped to 1-7/8 10.5” primaries into 2-1/8 secondaries for 10.5” with 2-3/8 choke into a 4” single tailpipe or 3” twin pipes.

I really liked the fat mid range of the single pipe on the last engine.... but im thinkin i may go regulat twin pipes this time, i think itll have too much power already without needing every last bit

By my calculations Eric has given you enough cross section to peak at 7000 so peak torque should be around 5500rpm give or take,
Not sure how much experience you have had with decent size converter but I would be going there for sure even if you don't go a real low rear gear,I have used my 8" 5600 in mild combos that peak at 6000 and they always run quicker at the track.
I would consider a twin 3" exhaust system as well just my opinion.

[54chevkiwi]

Burns spec’d tri-y headers 1-3/4 10.5” stepped to 1-7/8 10.5” primaries into 2-1/8 secondaries for 10.5” with 2-3/8 choke into a 4” single tailpipe or 3” twin pipes.

I really liked the fat mid range of the single pipe on the last engine.... but im thinkin i may go regulat twin pipes this time, i think itll have too much power already without needing every last bit

By my calculations Eric has given you enough cross section to peak at 7000 so peak torque should be around 5500rpm give or take,
Not sure how much experience you have had with decent size converter but I would be going there for sure even if you don't go a real low rear gear,I have used my 8" 5600 in mild combos that peak at 6000 and they always run quicker at the track.
I would consider a twin 3" exhaust system as well just my opinion.

Yea its a 9” jakes converter currently. I asked him about the new combo, he said to try this one first as it might already do what i want. Sound advice i thought. I mean, itll surely be less than optimal but at least ill have a benchmark for comparison.. gotta know where youve been to know where youre going type thing, you know?

[54chevkiwi]

Relief for connecting rods. Done with the 1” belt sander and smoothed with the scotchbrite wheel. This is 2 and 6..
1 and 5 need about .060 more than this, these only just cleared this amount of relief

[54chevkiwi]

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[54chevkiwi]

Hey so i probably shouldve specified this early on, but im not doing anything here thats revolutionary or reinventing the wheel, im just documentimg what im doing, mainly for the benefit of people who want to figure out how to do something. Like, i sometimes wanna see something close up so im offering this to other people on this thread. Thats why i posted it here instead of the other engine forum which needs membership and logging in to view.

[54chevkiwi]

Checked piston to valve.. cam degreed perfectly, i got .050 intake and exhaust where its meant to be and .015 intake and .09 exhaust advanced 2 degrees. Both ways with checker springs, checker pushrods, dummy gasket and zero lash with a dial indicator..
I checked with a running pushrod and the actual springs and got like .110 on both with lash and clay method trying not to squish the clay with calipers.. i can extrapolate ill have about .065 and about .140 2 degrees advanced...

I got a pair of lindytools relief cutters, i couldve cut the pistons at work but figured this wouldve been convenient, as we are too busy at work to have a machine available right now.. turns out i didnt need to cut them yet... i dykem’d the pistons and rubbed the top with the cutters, valve angles matched the piston tops perfectly,
i might tickle them radially a bit... in any case ill double check p/v when the shortblocks together and heads are resting in place

[54chevkiwi]

Carbs arrived courtesy of Braswell..
they sent me 1.36 x 1.69 4760s

Nice.

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[ClassAct]

Checked piston to valve.. cam degreed perfectly, i got .050 intake and exhaust where its meant to be and .015 intake and .09 exhaust advanced 2 degrees. Both ways with checker springs, checker pushrods, dummy gasket and zero lash with a dial indicator..
I checked with a running pushrod and the actual springs and got like .110 on both with lash and clay method trying not to squish the clay with calipers.. i can extrapolate ill have about .065 and about .140 2 degrees advanced...

I got a pair of lindytools relief cutters, i couldve cut the pistons at work but figured this wouldve been convenient, as we are too busy at work to have a machine available right now.. turns out i didnt need to cut them yet... i dykem’d the pistons and rubbed the top with the cutters, valve angles matched the piston tops perfectly,
i might tickle them radially a bit... in any case ill double check p/v when the shortblocks together and heads are resting in place

You have more than enough P/V to not notch the pistons. You’d be throwing away compression.

[54chevkiwi]

Yea i bought those things before i properly checked just incase i needed to.. i was happy i didnt haveto. Thanks for your input, i appreciate the confirmation i was on the right track.