Engine build
Thread Starter
|
Senior User
Joined: Apr 2005
Posts: 204
Likes: 1
From: Gillette, wy
Engine build
I have a 390, the block and heads are at the machinest right now. The block is getting magnafluxed, and bored .030 over. The heads are getting new guides, hardened exhaust seats, and new springs. I ordered KB150 pistons for it. I'm going to run the 343901 cam. Headers should be here next week, I want to stick with the two barrel carb. Which intake manifold should I use? Can I even use the stock 2 barrel with an aftermarket intake? Am I going to have to get shorter pushrods? The ones I have right now are stock length, i'm pretty sure they are anyway. Anybody have an idea of what the compression ratio would be with this setup(I don't understand the compression ratio calculators i found online) How thick would the head gasket be out of the felpro gasket set sold at my local napa?
Lead Driver
Joined: Jan 2003
Posts: 9,893
Likes: 12
From: Ohio
Don't think anyone offers an aftermarket 2bbl manifold, so I'd say you'll be using your original boat anchor piece.
As for pushrods. I assume you are using NON adjustable rockers, so I'd say you'll have to mock up your valve train and check for proper preload of lifters.
Long winded procedure: Set cam so both valves are closed on cylinder your testing(TDC of compression stroke), install pushrods and start to tighten rocker bolts. As you tighten down, rotate pushrod, then as it tightens down they will then become tight(hard to turn). Stop tightening bolts. At this point, you should only get maybe "1" turn more from rocker bolts. This will give you the needed .06 preload of lifter. If you get much more then that, you'll have excessive preload(might even bottom out lifter), and so you'll need to get shorter pushrods. If pushrod doesn't even tighten up after bolts are snug, then you'll need longer pushrods.
That was a lot of mumbo jumbo, but to make sure all is good it's a needed step. Of course if you use adjustable rockers, this is all NOT worthless information.
Don't have any other information for the rest of your questions.
As for pushrods. I assume you are using NON adjustable rockers, so I'd say you'll have to mock up your valve train and check for proper preload of lifters.
Long winded procedure: Set cam so both valves are closed on cylinder your testing(TDC of compression stroke), install pushrods and start to tighten rocker bolts. As you tighten down, rotate pushrod, then as it tightens down they will then become tight(hard to turn). Stop tightening bolts. At this point, you should only get maybe "1" turn more from rocker bolts. This will give you the needed .06 preload of lifter. If you get much more then that, you'll have excessive preload(might even bottom out lifter), and so you'll need to get shorter pushrods. If pushrod doesn't even tighten up after bolts are snug, then you'll need longer pushrods.
That was a lot of mumbo jumbo, but to make sure all is good it's a needed step. Of course if you use adjustable rockers, this is all NOT worthless information.
Don't have any other information for the rest of your questions.
Lead Driver
Joined: Jan 2003
Posts: 9,893
Likes: 12
From: Ohio
Not knowing all the specifics, doing the mock up is the only way to eliminate ALOT of problems that could come from mis-matched pieces. Some people get away putting stuff together blind.......I'm not one of them so I try to make sure to point out certain things.
From all the years screwing with this stuff I've found that: NOTHING IS A BOLT ON!!!! I don't care who made it and what they claim.
Just a typical story: Few years back I build new 428 for race car. Shop I use got me a new windage tray(Canton brand) since it was the 'new fangled version'. Come to find out after an all day fight with it that it only fit 390 stroke motors(they didn't specify anything on box). The extra stroke of 428 crank made it run into the tray everywhere. Lots of cutting, massaging, cussing I finally gave up on it and got a Ford stock version and it fit perfectly. Wasn't too pretty after I cut it to pieces trying to get crank to clear it. Ya....just bolt it on...LOL!!!
From all the years screwing with this stuff I've found that: NOTHING IS A BOLT ON!!!! I don't care who made it and what they claim.
Just a typical story: Few years back I build new 428 for race car. Shop I use got me a new windage tray(Canton brand) since it was the 'new fangled version'. Come to find out after an all day fight with it that it only fit 390 stroke motors(they didn't specify anything on box). The extra stroke of 428 crank made it run into the tray everywhere. Lots of cutting, massaging, cussing I finally gave up on it and got a Ford stock version and it fit perfectly. Wasn't too pretty after I cut it to pieces trying to get crank to clear it. Ya....just bolt it on...LOL!!!
