building a 360

[fishy68]

Originally Posted by mynumber38

Hey fishy just a quick question.I had the block bored 40 over.The cylinder measures 4.037 and the gasket measures 4.145 with a thickness of .055 will this gaskett compress to 4.040 or should I buy new gasketts.I am not really worried to much about the thickness,just dont want the gaskett to cover and of the cylinder by compressing to far.Thanks,Eddie

You'll be fine. I have never measured how much it compresses inward but I'm sure it's nowhere near that much.

BTW: Are you sure about the finished bore diameter? I'm not a machinist but I think the bore diameter should be 4.04 for a .040 over. The piston diameter is less to allow for clearance. If their forged pistons 4.036~4.037 is in the ballpark for what they should measure. Somebody please correct me if I'm wrong on this as I don't want to give bad information.

[mynumber38]

Originally Posted by fishy68

You'll be fine. I have never measured how much it compresses inward but I'm sure it's nowhere near that much.

BTW: Are you sure about the finished bore diameter? I'm not a machinist but I think the bore diameter should be 4.04 for a .040 over. The piston diameter is less to allow for clearance. If their forged pistons 4.036~4.037 is in the ballpark for what they should measure. Somebody please correct me if I'm wrong on this as I don't want to give bad information.

I did use a caliper/micrometer to measure the cylinders and that is what I came up with.Now the caliper could be wrong,after all I did buy it at a harbor freight discount tool store.As for the pistons they were speedpro .040 flat tops with valve rieliefs.I dont think they are forged because they only cost me 250. and some change.I dont know much about forged or not forged.They could be a forged piston.Thanks for the info!

[octanejunkie]

I would hazard a guess that the OP's measurement on the bore is off, .003" ain't that much to fudge with a regular caliper, regardless of it's source, you really need an inside mic or bore gauge

If there are concerns regarding the bore diameters or boring of the block I would contact the machinist/shop that did the work and ask what their tolerance is and whether they have any records of bore concentricity prior to their work, both parallel and perpendicular to the crank bore if possible

If you do call the shop I would also inquire into deck height, whether they took any measurements off the crank center line to the deck surface. Once you mock-up the build and measure piston-to-deck clearance you may want to mill the decks to square up your deck surfaces and set/tune your deck clearance, compression and quench.

[1wild&crazyguy]

Good ideas guys.

I would think a stock piston bottom end, given it's new, with .045 milled off the heads [of corse whats the current cc?] and .040 off the intake side, if you have to ..use the thin magnum intake gasket, 1 Step above a stock 340 cam like .468/268* or XE268*, rpm/ld340 dual plane intake, 650-700cfm carb, and headers would make 325-350hp

[mynumber38]

I am running speedpro .040 flat tops with valve rieliefs,280 474 purple cam-360 heads with 188 160 valves heads were milled 20, torker or air gap intake with 670 holley havent decided yet.I have installed clevite rod and main bearings.Also going to run headers,hoping to make 330 to 350 hp.The piston with number one up is real close to being flush with the top of the cylinder.What do you think of this combination,can I achieve my goal.Thanks,Eddie.

[octanejunkie]

Originally Posted by mynumber38

I am running speedpro .040 flat tops with valve rieliefs,280 474 purple cam-360 heads with 188 160 valves heads were milled 20, torker or air gap intake with 670 holley havent decided yet.I have installed clevite rod and main bearings.Also going to run headers,hoping to make 330 to 350 hp.The piston with number one up is real close to being flush with the top of the cylinder.What do you think of this combination,can I achieve my goal.Thanks,Eddie.

If you have the slugs in the holes you can measure your deck height (piston-to-deck clearance) and use the CR calc at kb-silvolite.com to calculate/estimate your CR - of course you will need to CC the combustion chambers of your heads and choose a gasket to work with as well as know the piston volume

All minor details add up, sometime considerably

[mynumber38]

Originally Posted by octanejunkie

If you have the slugs in the holes you can measure your deck height (piston-to-deck clearance) and use the CR calc at kb-silvolite.com to calculate/estimate your CR - of course you will need to CC the combustion chambers of your heads and choose a gasket to work with as well as know the piston volume

All minor details add up, sometime considerably

Anyone know if the airgap intake with mopar breather will fit under the hood of the 70 Duster Im building.I want to run this intake but I dont want to buy it if it wont fit.

[mynumber38]

Originally Posted by octanejunkie

If you have the slugs in the holes you can measure your deck height (piston-to-deck clearance) and use the CR calc at kb-silvolite.com to calculate/estimate your CR - of course you will need to CC the combustion chambers of your heads and choose a gasket to work with as well as know the piston volume

All minor details add up, sometime considerably

I have a quick question,I installed my stock rockers today and it seems they are putting the push rods in a bind.They are stamped 31 rt 32 rt 32 Lt 33Lt I dont uderstand what this is.I know there seems to be a left and right.Is there something I am over looking,do you know of a web site I can check out.I seem to have them on right know but it seems like the rocker is not sitting center on the valve.If you need a picture of this send me your email and I will send you a pic,that is if you dont mind helping me out.Thanks,Eddie

[fishy68]

Originally Posted by mynumber38

I have a quick question,I installed my stock rockers today and it seems they are putting the push rods in a bind.They are stamped 31 rt 32 rt 32 Lt 33Lt I dont uderstand what this is.I know there seems to be a left and right.Is there something I am over looking,do you know of a web site I can check out.I seem to have them on right know but it seems like the rocker is not sitting center on the valve.If you need a picture of this send me your email and I will send you a pic,that is if you dont mind helping me out.Thanks,Eddie

Your correct that there is left and right and if not in the right place they won't be centered on the valves. I wish I had a pic to post but I don't. There pretty easy to decipher which way they go if you look at them. Move them around until you get them in alignment. As far as the numbers I have never noticed numbers stamped on them but in honesty I have never looked very close.

[mynumber38]

Originally Posted by fishy68

Your correct that there is left and right and if not in the right place they won't be centered on the valves. I wish I had a pic to post but I don't. There pretty easy to decipher which way they go if you look at them. Move them around until you get them in alignment. As far as the numbers I have never noticed numbers stamped on them but in honesty I have never looked very close.

I will take them back off and move them around untill they seem to fit.They are on there now but dont seem to be center on the valve.Thanks,Eddie

[fishy68]

Originally Posted by mynumber38

I will take them back off and move them around untill they seem to fit.They are on there now but dont seem to be center on the valve.Thanks,Eddie

That's what I did the first time I did one. You'll get it.

[mynumber38]

Originally Posted by fishy68

That's what I did the first time I did one. You'll get it.

Yeah it was pretty easy once I got into it.I marked the ones that were right on one side and the ones that were wrong on the other side and switched them and that was the fix.Thanks again.

[spstacman]

so i am working on getting all the pieces together for a 360 build i think i am going to run kb107 pistons do i have to worry about the valves clearing the piston

[octanejunkie]

Originally Posted by spstacman

so i am working on getting all the pieces together for a 360 build i think i am going to run kb107 pistons do i have to worry about the valves clearing the piston

That depends on many things, namely how much lift cam are you planning on running, what heads you are running and whether the pistons pop out of the bores, among other variables...

[360moparjunkie]

Originally Posted by spstacman

so i am working on getting all the pieces together for a 360 build i think i am going to run kb107 pistons do i have to worry about the valves clearing the piston

I think you can use clay to measure your clearance to valve during construction. You are not there yet imo.

Start a new thread with all your piston clearance questions as well as any others.

You will have 100x the exposure to the questions will have. Members have to stumble onto your questions this way. Just trying to help you out.