270 GMC altered motor build part 1

What a great post, as Exderelict says, drool cup needed. He has found his own 302 (courtesy of the great state of Kansas) and shown in pix is the pull form the U.S. Army truck yesterday. Watching with great interest and appreciate all info in this thread. Here we go! ~sololobo~

 

good score on that 302
I started porting the head today I'll post some pics later

 

We got the header back from the chrome shop yesterday MMMMMMMMM chrome.
Don at Show Quality Plating in seattle did the work .

 

great work so far keep it up any chance of getting 2 of those injector castings if so pm me answer to previous post about bottom end problem on drag strip can be found in one of last years national dragster an article by reahr and morrision has to do with harmonic feedback to engine due to tires. think the selfs from durant ok. can give info on this also

 

Yowza! I love inline 6's! This Jimmy's gonna SCREAM!

 

I'm thinking about making some more, I'll let you know . Do you want raw castings or a bolt on unit ?

 

Man, I can't wait to see this thing go together. I have one big question though... With that crazy expensive head and the beginnings of a kick*** engine. Why would you use a stock rod? Looks like no expense has been spared elsewhere. Why not put a billet steel rod in this thing for insurance?

 

This one is just to get the car going and work out the bugs. We are building a better 302 with all the good stuff it will be set on kill ,12 port ,blown on nitro,billet crank ,alum rods

 

Ahhh, I see. I couldn't sleep knowing that head was over a stock Jimmy rod. You are a brave man.

Looks great, keep us updated. I love these engines.

 

I ran stock heads with up to 21 pounds of boost. Unblown Howard head, and a Horning/Fisher 12 port with 22 pounds. All with stock rods and no failures. Eventually I went to a Crower + .625 rod because of wristpin placement. Much better deal, but never broke either one.

 

Did you have the rods Mag'ed after polishing (I hope)?

 

NOS rods I did not have them mag'ed after. Is there some thing I missed by not doing that?

 

raw casting will be fine i had drawn up basicly the same thing and was going to see if i could get brodix to cast them but havent had a chance to go to mena due to weather this would save me making pattern ect. going to put them on a 2.0 ford using hilborn pump with belt drive in either a king or 58 fed ch***is probably run alky

 

Subscribed !

 

For a new rod nagging isn't as important, but it would show any issues with original machining/forging...on the outside at least. If you're using stock rods I ***ume you aren't going for super high hp or rpm. An important note is when shot peening to remove the rod bolts as the sharp machining surfaces around the rod bolt head are one of the highest stressed areas on the rod and the sharp corners/edges act as stress risers. To find any internal inclusions you would have to go to ultrasound/x-ray, but a full gambit of ndt would put you in the ponderous state of questioning aftermarket rods...
Hans

 

Magging...nagging....whatever it takes...

 

I've polished lots of rods and found laps, cracks, laminations and other defects that didn't show up on first Mag. Would be a shame to put that much work into them and have one fail. I always checked them after polishing. I've pitched out some too. It's cheaper than a new engine.

 

Thats good info, Thanks, both you and hans

 

There is nothing better than an injected nitro burnin GMC! The one in my pops bonniville car is off the hook! You will have fun.

 

When one is an old fart he starts to believe real cutting edge innovation has given in to the "hand it to me over the counter" syndrome and then someone like you comes along and makes the world brighter again. Thank you. I am SLOWLY chipping away at my dohc 4v 302 Jimmy project and making many notes since the old guy with the long whiskers and big blade over his shoulder might catch up before completion. Original intent was to split lengthwise and mill in coolant p***ages but time restraints probably means a straight billet piece for just drag use. Was planning on triple Weber setup but your injectors have definitely caught my eye. Also considered one bbls for just air flow control and electronic injectors for fuel. Am keeping photo record but really don't want to disclose till finished but here are a couple of shots of things for the pull tractor. Block is fresh from the 5 axis mill (note chips underneath and oil still dripping) and the 2v head has unfinished valve pockets and dual spark plug holes. Unless God tells you then you will NEVER know why it is in the s**** bin.

 

WOW thats cool

 

Marshall, Wicked build!

Good talking to you yesterday!

Oh, and I made a deal for that Skinner head.

 

Can't wait to hear it. Nothing sounds like a Jimmy, e****ally with a 12 port... Awsome headers !!!!

 

I will see what I can do.

 

I called on the castings to day and I sould have about 10 more bodys in about 4 weeks or less

 

subscribed! thanks for posting Marshall

 

marshall; you are a true gentleman and scholar even if you did spend longer in third grade than i did. your effort on my part is far beyond the call of duty. b.s. over now when they get to you tell me what i owe and i will pay and send address again a million thanx

 

Awesome build! What are you using for Rockers, push rods and lifters??? Or is that a secret???

 

Subscribed...........

 

Marshall, re you using a one piece pushrod, or the two piece?