Thx!

Yes 4/7 swap

@@TinIndianPerformance Wow that was a good pull. You know I just dont understand the 4/7 swap . I also have a 535 butler motor that I am building is there any tips you can share when building a motor like this.. I also have the aluminum block

​@@rogersampayan9192 4/7 swap Once there is sufficient overlap in the cam, what happens is you end up with a lot of turbulence in the intake. The four seven swap, takes advantage of the turbulence. Reduces it, and the same time allows the intake charge that has been built up from number two, to be fully used, and efficiently drawn back into number 6

Here’s a pretty good way to think of it based on the facts of it being an 8 cylinder and a 4 strokes per cycle engine. the crankshaft revolves twice in the cycle. two revolutions equals 2x360 degrees or 720 degrees. no two spark plugs fire at the same time; they fire in the firing order. the 720 degrees is thus divided by 8 and thus every 90 degrees of crankshaft revolution another spark plug fires which is very close to the end of the compression stroke. if # 1 piston is at the very end of the compression stroke where the spark plug is about to fire, #8 piston will be half way up its cylinder on its compression stroke with another 90 degrees of crankshaft rotation to go before it’s spark plug fires. the next one, #4 will be near bottom dead center at the end of its intake stroke and commencing its compression stroke. continue with this sequence and we can see that #6 piston is in the same position as #1 but finishing the exhaust stroke. #5 will also be on the exhaust stroke but 90 degrees behind # 6. Incidentally, you can time the engine off of the plug that is the next one beyond the halfway point which in this case is #6 because the vibration damper where the marks are is in the same exact position whether it is #1 or # 6. If timing is 6 degrees before top dead center both pistons #1 and #6 will be in that same position. Put your timing light on #6 and you will see flashing of the timing marks indicating the same 6 degrees before TDC.

Not sure that we would do that as we already kind of know... (280 cfm is pretty stout flow for a cast iron head!) 240 + cfm 6x with a RAIV style cam 460 ish cubes makes about 450 ish hp - stock intake - Q jet. Same cid with a 85 cc 290 port - same cam - Performer RPM- HP4150 style 950 carb- makes 530 ish HP. We have used cast iron for years... we can make more power with the KRE heads hands down.

@@TinIndianPerformance I know the Kauffman heads are a lot better, just want to see how close fully ported iron heads would be. I'm into getting the max performance from stock looking engine.

@@tomsettles6873 We get it but that sounds like a great test for YOU to do! The cost of porting cast iron and the fact that they would be paper thin at 280 cfm - we have NO interest! Running on pump gas you will be limited by the 9.5 to 1 compression....Sounds like a great test.... Let us know ;-)

no way to safely port 6x's to 280. McCarthy's book gives a step by step procedure to get 250 which is 500hp. That's it for cast irons - waste of time porting them as it takes forever when you can buy Kauffman or Edelbrocks that beat ported cast iron out of the box@@tomsettles6873

Not on this combo - just showing what we did

@Tin Indian Performance I come from european and japanese car circle I appreciate your content for keeping the pontiac love alive.My dream build is 3 gen pontiac f body gta with! the real pontiac engine EFI 6 speed Independent rear Suspension.

We do EFI builds - just not this one

Your ignorance proceeds you! LOL - First off, this engine IS NOT 50k - second - Yes those are Pontiac parts! They are not "stock" Pontiac parts but those heads will bolt onto a stock Pontiac block AND stock Pontiac heads will also bolt on to that aftermarket aluminum MR-1A block!

Hey Tom. If you would like a quote, shoot us an email at Sales_Team@tinindianperformance.com

Aluminum MR-1A 4.350 bore for NA - Superchanged it depends on the amount of boost

YES! - No power adder

Well not really.... it is an aftermarket MR-1A aluminum block - 4.250 bore with a 4.5" stroke - this is a 3" main engine...

@@TinIndianPerformance o ok..

4.350 bore - 4.5" stroke with 56 cc heads - a little over 15 to 1

@@TinIndianPerformance thank you

@@MrPONCHO467 Whoa! 15-1? Almost a diesel. I like it. :)

Nope - if ANYTHING, the dyno used is typically pretty conservative!

don't even respond to morons making uneducated statements like that@@TinIndianPerformance