ok.....latest update. motor torn completly down. it has a double roller timing chain, the edl-7102 cam and the rods and pistons look to be fairly new. the pistons are a shiny type looking aluminum style. not sure if that's stock or rebuilder pistons. I also found some metal, which looks to be part of my dipstick. I looked at the dipstick and sure enough about 2-3 inches is missing off the damn thing. so im wondering if that's what caused my gouge in only one cylinder. question is can I still make it into the 12s if I don't get the block bored over to a 355? I looked up the strokers and there pretty expensive so that shoots that idea down. anyones thoughts?

 

Look for #'s on the pistons, on the bottom, on the side near the pin or on the top (might have to spray carb cleaner to get the top clean enough to read them) - if they're "quality" pistons there will be a part number on them somewhere - if they're just the cheapest of the cheap cast rebuilder pistons there will either be no markings on them or just the oversize marking on them (i.e. .030) Post up a pic of the pistons from all angles if you're unsure about them - also if you have a caliper you can measure pin height and find out what that is.

The bore - depends on what the scratch looks like, if it can be honed out without going to an over-bore is up to a machinist to measure and visually inspect it. I'm going to suggest the answer is NO and you'll need to do at least the next overbore up from where you're at.

 

the bore partwould be on the new block i got. the old block is going to become a paper weight. how do i measure the pin height. there some numbers inside the pistons so ill research them more this evening after i pick up the new block

 

Get a bore gauge and measure the new block in at least 3 locations of the bore (top, half-way down, and bottom). Compare those numbers and see if the bore is out of shape. i.e. typically barrell shaped (bigger in the middle) or tapering from one end to the other for a bore that is wore out. Next you should measure the bore using the gauge in the front to back vs the side to side measurement - that will tell you roughly if the bore is round - they usually have more wear on the 'sides' of the bore due to the way the piston rocks during use.

Take the measurement of the piston diameter and add the clearance for the type of piston and application you have. (look up the MFGR recomendation for the piston to wall clearance) SO if your piston measures 4.0000 inch and your bore measures 4.0015 you have .0015" clearance - that's the only way to tell for SURE that your new block will or won't need to be bored over. Do that for each cylinder.

Get the numbers off the pistons and you'll probably find the MFGR and Spec's on the internet for everything you need to know and since it'll have pin height as one of the spec's there's no need to measure it. (but fwiw - it's the distance between the piston pin and the top of the piston (flat area and not dome if it's a dome top piston)

 

Now that sounds vaguely familiar.Who said that???. Opps,it was me!!.

Most SBC's have a taper worn into them from use.It's common place to find that.

 

well got a number of the pistons, turns out they are .030 over pistons with p.n. 17350.

 

ok now knowing that indeed that it is legit 355 sbc stuff, would it be worth to just by a re ring kit, bore the motor .030 over, and put back together with the 268xe cam, and the .041 head gasket to make it 10.1 compression 12 second car?

 

If the rings aren't sealing, then your engine will never make the power that it should! Since nobody else has mentioned it thus far, you shoud take a look at Rhoads lifters. They are variable duration, which means you could take 10-15 degrees out of the cam at low RPM and as your revs increase they restore full lift and duration! Which means you would have a powerband that started approximately 600-1000 RPM sooner. Also, that will be a hell of a lot cheaper and easier than a cam swap! At idle they allow you gain 1-3 inches of vacuum. Check them out a: rhoadslifters.com.

 

ok I got all the part numbers out of the motor. only prob is I cant fins stampings on the connecting rods.

crank: 3932442
pistons 17350 030

 

http://www.summitracing.com/parts/sum-17350-30

At least you got a 355

 

yes but i'm not using the 355 block that everything came out of. I got a new block going to get it bored 30 over and use all the stuff from the old motor i.e. crank rods pistons. im getting a lot of conflicting information from this thread to other threads about how the heads aren't going to work with the 268xe cam, and that I should leave the cam I have cause the heads wont make it the way it should be. now ive been throwing out the idea of getting 190cc heads or building a 383 to use the heads. which route would be smarter on the budget I have?

 

If you are going to buy new heads stay away from pro comps. What is your budget?

I love my patriot vortecs but I only have about 2k miles on them so I cannot attest to how reliable they are.

http://www.jegs.com/i/ProMaxx-Perfor...14#moreDetails

They have smaller intake runners and flow better.

Looks like with factory vortecs and a xe268 cam you can make about 370 hp

http://www.hotrod.com/techarticles/h.../photo_18.html



Research for a while then buy the parts. Post a list of what you want to buy.

 

just sucks I already spent so much on theses heads with all the upgraded items that I cant use them ( buddy at work said to run these). might sit on the build for awhile then see what I wanna do,

 

You can run them but they are not ideal.

 

ok i called skip white and there saying with the combo i had in the begging of this thread i should be in the 12s no prob. they suggested the timing be set at 34* around 3000-3500, and car would be able to rev all the way up to 5400-5800rpm with no problem. he also suggested to try the howards cam: http://www.ebay.com/itm/SBC-CHEVY-HOWARDS-HYD-FLAT-TAPPET-CAM-110051-10-ONLY-/330885099431?pt=Motors_Car_Truck_Parts_Accessories&hash=item4d0a49efa7&vxp=mtr#ht_7980wt_1088and bring my stall convertor up to 3200-3500. are they blowing smoke up my *** or are they in the ball park area for improvement?

 

Yes that cam will work with your heads. It will produce nice top end power and **** low end.
The grind is very similar to the edlebrock RPM performer

get a 3500 stall and you will probably be close. That is the combo skip puts into most of his "400hp" procomp engines.

 

It is not too different than what you have now.

Howards cam
Cam Style: Hydraulic flat tappet
Basic Operating RPM Range: 2,800-6,200
Intake Duration at 050 inch Lift: 235
Exhaust Duration at 050 inch Lift: 243
Duration at 050 inch Lift: 235 int./243 exh.
Advertised Intake Duration: 289
Advertised Exhaust Duration: 297
Advertised Duration: 289 int./297 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.488 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.507 in.
Lobe Separation (degrees): 110
Camshaft Gear Attachment: 3-bolt
Computer-Controlled Compatible: No
Valve Springs Required: Yes
Camshaft Manufacturers Description: Lopey idle, serious street/strip. Needs 3,200+ stall, headers and gears.

Your cam
Cam Style: Hydraulic flat tappet
Basic Operating RPM Range: 1,500-6,500
Intake Duration at 050 inch Lift: 234
Exhaust Duration at 050 inch Lift: 244
Duration at 050 inch Lift: 234 int./244 exh.
Advertised Intake Duration: 308
Advertised Exhaust Duration: 318
Advertised Duration: 308 int./318 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.488 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.510 in.
Valve Lift with Factory Rocker Arm Ratio: 0.488 int./0.510 exh.
Lobe Separation (degrees): 112
Computer-Controlled Compatible: No
Lifters Included: Yes
Lifter Style: Hydraulic flat tappet
Valve Springs Included: No
Retainers Included: No
Locks Included: No
Valve Stem Seals Included: No
Timing Chain and Gears Included: No
Assembly Lubricant Included: Yes
Pushrods Included: No
Rocker Arms Included: No
Gaskets Included: No
Valve Springs Required: Yes

 

damn i wasnt even paying attention to the grind how close they were. so if i want low end power i need to go with the 268xe or the 274 from comp and ill be better off then with the cam i have now?

 

I like the Xe274, I run one with my patriot vortec heads. It seems to have a fair amount of low end grunt.

I am running 64cc heads giving 10:1 compression, 185CC intake chambers, 2.02, 1.6 valves. They flow fairly good about 245 at 500 lift.

When I mash the gas I smile ear to ear, great sounds, tons of pull and seems streetable.

You could always reuse your cam, there is the possibility that your bottom end was killing your performance along with your TQ converter. Your edelbrock cam wants a 3000+ stall.

Notes for your cam

 

Bring it up into the power band with the TC.Also the 185cc runners do help abunch on the low end power.

 

the cam went bye byes that's why I asked about the cam I was pissed at the performance so I sold it lol

 

I would probably get the 274 then.

 

how do I measure compression or even start to figure it out? I have the summit 17350-030 pistons but they don't say what comp there good for

 

Pistons are only one of about 6 things that determine static compression

Try the summit calculator

http://www.summitracing.com/expertad...ion-calculator

 

whats all needed to make a 10:1 comp motor?

 

Pistons, gaskets, block, bearings, crank and heads.

 

no ****?? as in what is needed. is there a specific piston, gasket, size that i will need?

 

The number of combinations that can be used are in the 100,000s.

Start by opening the calculator in the link I posted.

Then put in the info for any parts you have already bought or are reusing. Items like bore, stroke.

Then pick out what heads you are going to use. Put in the numbers for the combustion chamber.

Then pick out your pistons put in those numbers

Finish by fine tuning it with gasket thickness.

You can use any standard value to start, change the values and see what the effect is on the final number.

 

I read that you removed your car's swaybar. What is the reason you did that? and does it not hurt anything?

 

Billy.Not sure I would have a goal with iron heads of 10.0.I suggest you build into this a 9.5.And don't just look at out of the box combustion chamber sizes.You could get a intake runner size that would work great for your combo,but the heads are say 72 cc combustion size.No big deal to cut them to say a 67 or 68 size to tailor those heads to your needs.

 

i removed it for a better launch,better weight transfer, and weight saving. doesnt hurt anything just dont turn a corner at 100mph and youll be fine

 

how do i figure out the deck clearance and the stroke? thanks guys

 

This is one ratio you need to consider.

http://www.wallaceracing.com/eff-cr.php

 

Factory deck clearance is about .025 you will have to measure to be sure.

Factory stroke will be 3.48. About 30 seconds on google can provide that info.

With that being said both will change depending on what parts you put inside and what machine work is done to the motor.

 

i never messed with stroke size or deck clearaces and google gave more then one stroke size thats y i asked how do i measure it.

 

The standard cheap rebuilder's pistons have a very poor pin height and for deck clearances that matters.

 

OK contacted comp cams and they recommenede this cam http://www.summitracing.com/parts/cc...50-3/overview/. i want to get the most out of the heads, plus be able to drive it on street. with that cam would i be better off ditching the 2800 stall and go upwards toward 3200-3500 or do i need to go higher then that?

 

No. Do not go that high on the cam. Xe274 is all you want in a 350. That cam would need 4000 -4200 stall to work best at the track but would drive fine with 2800 on street. Just be soft between 2800-3600 or so

It would however likely get all the power out of the heads but you will need to spin it high. Not the greatest street driver

 

im going to go with the 274xe, should i install a 3200-3500 stall since motors already out, or leave the 2800 stall?

 

Trade off on the street is a looser T/C will get you up into the power band sooner,but with a limited cam kind of shortens the power band too.

 

I finally got curious how a cam thread got 4 pages long, that seldom happens. I usually lose interest in threads as they get longer and longer. But since this thread isn't dead, I'll add my response to the original post: Order a cheap, generic cam to get a new baseline. Something mild enough to restore some low-end, but not so small that you lose much upper-RPM. Something like a 214/224-112. Then once you try that, start a new thread with a more intriguing title.

 

i cleaned the pistons up real good and theres some knicks and gouges on the flat top of the piston and ones got a little nick on the side of the top. is these pistons bad?

 

We need pictures

 

ok ill take some when i get off work, they look like rocks have been pounded into them and pulled out leaving the gouges

 

You didn't use to clean the pistons a red 3M gasket cleaning pad I hope.

 

heres the piston pics. the black marks are where the damage is. let me kno what u think

 

they are added below. i bought my rebuild kit witn new bearings, amins, pistons, rings, and the plastigauge stuff. what would be the ideal clearances for the piston to valve, and the crank to block? is there a recommende spec or is it what the builder recommends?