DeltaElite121

honestly, the kinds of problems he's experiencing from something with that kind of mileage has me curious to see what the rest of the bottom end looks like. That's definitely not normal.

+ Billy, if you decide to do a roller cam swap (I have mixed feelings about this personally) - I can get you a custom cam from Chris Straub for a decent price since I just filed for a dealer account with him... which also coincidentally includes stroker kits and just about everything else you'de need.

1gary

Delta is one of the good guys on this site.

I'm a engine builder for many yrs trying to get you to face reality. The range of what is going on with this is endless.To ask for performance on a hurt engine isn't practical.Then compound that with a yr engine that requires a roller cam conversion where neither a flat tappet cam or to spend money on the roller conversion doesn't make sense.By far to get a 1996 to 2000 rebuild-able truck L31 engine is a step in the right direction wither it be a 355 or a 383. That isn't talk from a hot rodder,it's pure dollars and long term sense.Saving money.

The rebuilder's kits for pistons often have pistons that have very poor piston pin height's and poor quality pistons themselves.Fact is in this world of engines you more often get exactly what you paid for or less.

My approach with a stroker is that you have capital invested in heads already,so for you to realize the performance back from that investment you need to up the c.i. size of your engine.In doing that your going to lower the power curve and get use of your already invested money in the heads more often in normal driving rpm ranges.Understand this,if ya want to play,your going to have to pay.

Is there 355's out there producing 300 hp??. Yes,thousands of them. But the history of that goes back to when the oils for flat tappet cams was the normal not needing additives or special oils. What I am trying to get you to see is in the long run,it by far cheaper to build a roller L31. That is the way to get around the possibility of a flat tappet cam failure which would end up you being right back where you are or worst.And the roller cam's profiles are substantially better.

1gary

I haven said this yet.THERE ISN'T ANY STAND ALONE PART THAT IN IT BY IT'S SELF MAKES ANY DIFFERENCE IN THE PERFORMANCE OF A ENGINE LIKE A CAM SWAP.

billybob6110

im curious to, so until the teardown im kinda screwed and outta commision. car drives and starts normally just no power, kinda makes me wonder if the guy i got the motor off of really "screwed" me in the end.

DeltaElite121

Don't spend any coin until you get a good look at things. My guess is you're going to crack the motor open and have a few surprises waiting. We all make mistakes. The difference? Learn from your decisions, and they won't be mistakes. No regrets. We will help get you back online, no worries.

midias

Did you install the cam?

If not it may have been installed a few degrees off.

billybob6110

im not sure if im ready for the "suprises" what else in the bottom end could cause issues like im experiening. im learning and taking in all i can so bear with me

midias

Start by taking the heads off and checking the cylinder walls for damage.

I have seen all sorts of interesting things with engines other people built. My favorite was a stamp steel rocker that was randomly 1/4 longer than the rest. Caused a valve to drop and destroy the engine. Fortunately I helped my friend find a good L31 long block for $200 and we rebuilt. Made a nice reliable 350hp 350 for about $1500.

billybob6110

ok thats a good starting point ill prob start ripping into it this week sometime. its a little late to mention now but ive fouled a few plugs sets from the oil this year, but the weird part is i have to retime the motor everytime i put new plugs in it. it doesnt make sense to me but itll be really "retarded" once i change them. is that caused by lack of spark when i put the plugs in from the old, or could it be timing chain/cam lobing going bad. i think i got ALOT of issues with this boat anchor

midias

While you are removing the top end you can check other things. Look at the lifters for damage. Also make 100% sure that you label the lifters they have to go back in the same holes they came out of.

Look at the tops of the valves for damage.

Does your distributor move by its self?

billybob6110

i didnt install the cam. i bought it like that. it had the cam and bottom end installed. i put the upper part together going off the information i was told by previous owner which claimed was a 12 second motor. the distributor is tight as can be and doent move while its bolted down. i tried in several occasions to see if it would and it wouldnt.

midias

Sounds like you have a lot of things going on with that motor. Take it apart, get part numbers of everything you have.

Post back with the items you have in your possession then we can probably help you get it all together right.

billybob6110

sounds good thanks for the help

billybob6110

just a thought could the carb be running to rich giving me the oil look on the plugs and fouling them out. it looks and smells like oil, and the electrodes all the way down are black sooty looking. just asking so i know whether or not to rule out excessive fuel. trying to break everything down and analyze so i dont have to do this again. but i dont believe excessive fuel would make it lose that much hp. possible the intake not sealing properly causing issue? theres a small oil leak on the front valley seal but nothing major.

billybob6110

ok ran a compression test. results below

cylinder:
1 133psi
2 142.5
3 141.5
4 134
5 142.5
6 142.5
7 125
8 123.5

Orr89RocZ

iTrader: (20)

That warm or cold? You may not have the compression they originally said but also that cam is gonna bleed off alot. You definately want cranking compression abit higher than that to feel torquey

billybob6110

that was done with a warm motor for 20 minutes, plugs out, and rotated engine for revolutions then got the reading.
also when i first started the engine to do the compression test alot of oil blew out of the plug area. in the plug hole there all puddled up from excess oil. is it possible my problem is a faulty intake manifold gasket/seal? seems like alot of oil to blow by the rings

1gary

These things I am about to posts are guesses not being there.If I where you,I would want to leakdown this engine before I took it apart.Also spray the intake mating surfaces with carb cleaner while it was running and if there a change in idle,then a intake gasket is involved.
Now if it is running that rich,there is a possibility the cylinders are being washed down with gas and the rings worn out,well really the oil rings.
I've posted dozens of times about compression/cam comparability.DCR's matter where actually the intake charge is being polluted with exhaust gases and forcing the intake charge back into the intake manifold. A rich running condition fouling plugs. Poor quench numbers also plays a role in poor performance.Compound that with relative huge intake runners doesn't help either along with a long duration cam,cam timing,and the low compression not to support it.That is the definition of a classic miss matched build.

You never said if this engine cold start has a puff of smoke out the exhaust.Again if it where me,I would want to look at the valve guides/seals,to see if those where worn from poor oiling with gas in the oil.

Not knowing the engine builder,I would want to know if the proper ring gap was there and if the ring gap was spaced correctly.If the bores are not scored,take some light oil into the cylinders and coat them.By hand turn over the engine and look for a pattern on the bores.If there is a line in that oil pattern,that is something to look at more closely.
This is a do-over.So you want to look for clues.Measure the pistons from the deck and then do a SCR calculation.Measure all the lobes at the rockers to see if you now have a lobe or more worn than the others.

Again this is a do-over..............................so you can't over look any possibility.

billybob6110

good explination im probably going to buy a bare block and start from scratch using the heads intake and carb that i already have. what is the best way to go about doing a stroker motor to support the heads i currently have. rather build what i kno i have, then assume what is there.

midias

You would have to buy a 383 rotating assembly and install it in a 350 block. Be careful a 383 is a 350 bored 30 over with the kit so when you get your kit make sure to get one for the proper bore of your engine.


BEFORE you order anything start tearing the motor down. For the price of the 383 kit you could probably pick up a better set of heads and get your 355 into 12s if the rest is in good shape.

Orr89RocZ

iTrader: (20)

Find out why your motor doesnt work now before doing another and possibly making the same mistake twice.

Valveguides and seals may be shot and leaking oil or better yet an intake gasket leak causing all kinds of tune issues. I'd atleast pop intakeoff and inspect head ports for oil. Give it a shot. If the heads are damaged i would prepare to spend money to have them properly worked over or just cut your losses and buy new ones

billybob6110

what damage would be "obvious" and which would not? if there damaged at all

Orr89RocZ

iTrader: (20)

Valves will wiggle alot in the guides if damaged. Seals may have some visable damage to the sealing lip area around the stem. Ports will show oil perhaps even in the exhaust port if exhaust guides are bad. Just things to look for

I am just really curious what could be holding this motor back over a second and a half and 15 mph +

billybob6110

me too im gna remove heads and intake after wrk ill update the bore size and if any damage to the heads. also what should i be looking for on the cylinder walls besides cracks, and deep gouges?

billybob6110

well I just pulled motor apart and guess what I found?????
a 4.0 bore, and a nice crack/really deep scratch on cylinder 7 and the other cylinders a smooth but with visible scratches on the cylinder walls. so now im at the point of saying...now what?

bygddy

Now its time to make some decisions. Budget wise, send the block to the machine shop, see what they think about your "scratch" and if a 030 over will fix it.
If money is super tight, buy the summit .030 rebuild kit, they are really KB hypers and 1.560 pin height.

Have your heads checked, if all comes back good, have the motor zero decked.
Look at the xe268, or even 274 as ORR suggested, either will get the job done.
Using those heads, I would use a 1.6 rocker on the exhaust side.
Button it back up, throw a 650DP on it, go run 12's

If you have a tad more, go Garry's route, and pick up roller block,
Same summit rebuild kit
This cam with 1.6 rockers
http://www.summitracing.com/parts/hr...make/chevrolet
And go run 12's

billybob6110

so basically im going to be making an actual 355 sbc with these parts? makes me mad that after all this tinkering and what not the motor isn't even what I was told it was

billybob6110

and wahts zero deck? make it flat basically? also is there a performance difference from a 350 to a 355? I can get a virgin 010 block for free, is it worth the extra bore?

bygddy

Your pistons are generally 0.025 in the hole on an average stock block. This, combined with typical rebuilder pistons which are usually around 1.540 pin height, will cause lower then wanted compression, and a much larger quench area then wanted.
Using the summit pistons, which as I said is a rebranded KB piece, with a 6cc relief,
And a pin height of 1.560, zero deck the block, and a .041 head gasket gives you a "true" 10.2:1 compression and an ideal quench of 0.041.
With your alum heads and ideal quench you can run full timing, (18* initial with the xe 268 or 20* with the xe274 and total of *36) and run it on pump gas happily.

bygddy

If your "virgin " block is brand new, then by all means use it, no your not going to notice 5ci
But you will still want it zero decked and checked out at the machine shop.

1gary

Virgin block like new or one that is "claimed" to be good to go at a 4" bore??.
These 350's are known to have piston rock in the bores so to find by dial bore checking all the bores in multi locations to see if any are oval.Never rebuild without a mag check and atleast a good cross hatch machine shop hone.Also a hot tank cleaning with new cam bearings and new soft plugs.
The idea if a 010 block having value is real old school.I know that one being I have spent my entire life as a hot rodder and will be 66 yrs old in acouple of wks.On the other hand to find a rebuild-able L31 cheap isn't that hard and by far those have advantages far beyond a 010 block.They do machine much better than the older stuff.

This advise is so you don't have a repeat of what you have now.Trust in the fact each piston manufacture wants their pistons clearance to their spec.So finished sizes should not be done unless the machine shop you trust has the intended pistons you want to use in hand.Also it's a dollar short and a penny smart not to set the DCR/quench with a deck height while the block is at the machine shop.Low dollars spent and great returns.

bygddy

Which is what I said without all the pomp and circumstance.
I will simplify without using stories of 147 years of engine building experience or owning 14 four second jet propelled race cars.
Have a reputable machine shop tell you what pistons to order after they have gone over either your current block, or your "virgin" block.
If money is tight, go flat tappet, either one I listed, follow the breakin procedure like its religion, you will be fine.
If money isn't so tight, go buy a roller block, same machine shop advise, use the roller cam I listed, you will be fine.
Either way, a good machine shop and attention to detail will provide you with a strong, reliable motor that meets your performance goals.
Make sense

bwiencek

Sounds like you're on your way to getting it right... Sucks that what you thought it was on the bottom end it really wasn't, but at least now you know and can do it right...

For a 'budget' rebuild the summit kit can't be beat, or for a little more displacement Northern Auto parts has a budget 383 kit:
http://www.northernautoparts.com/Pro...tModelId=18798
(click on the show options for a list of other stuff you can add to it) - plus if you call them they'll swap a cam of your choice in the kit for just the difference... (Summit also has a 383 kit but it's less complete - no gaskets, etc.)

If I had a choice between building an old 2-pc rear main block and a late model roller 1-pc rear main block - I'd go the 1pc rear main every time... Like everyone said - hit up craigslist and look for a 350 engine that has a roller cam or can take a roller cam (look at 96-99 5.7L vortec pickup engines as they all have roller cams and you can find them cheap with a knock or blown headgasket/blowing oil) Find one with a good crank if you're going to stay with a stock stroke (then you usually don't have to cut it - just polish and run std or .001 bearings depending on measurements) or go for the cheap route and pick up one with a knock if you're going the 383 as you'll replace the crank anyhow...

Read up on the following subjects:
- Quench
- Dynamic Compression Ratio (and DCR vs Octane requirements)

Since you've already got a set of (presumably) good heads (double-check them) then I'd build around them and choose parts to optimize their performance. Just remember there is more than one way to reach a good quench # - FelPro makes everything from a .015" shim head gasket to a .041 in their 'standard' lines and that's not getting into the high performance stuff - pretty much if you've got a quench clearance you want to hit you can find a gasket for an SBC to make up that clearance (i.e. you want .041 quench and the pistons are .020 in the hole - you need .021" head gasket (and really +-.002" would be close enough since there are cheap .019 and .020 gaskets IIRC - especially if you didn't want to machine the block or get a more expensive gasket to save a buck....

billybob6110

ok ill know more once i completly pull the motor out, and see how bad the scratch/crack is. almost all the cylinders have a nice score mark or have some sort of gouge in them.

1gary

Just one more thing.......



Yep-in pm's I did tell this user where to go to get all his questions answered because I didn't have time for all of them.

You know the drill:



Please no thumbnail photo's.Not enough detail.

1gary

This sounds like"without pictures" a engine who's bores where not checked for roundness and the bores not being set for proper clearances.The damage on one bore more than the others with a line would get me to look hard at that piston's rings.Round rings don't like non-round bores and the possibility of the ring ends flipping over scoring the bores or seizing on the ring lands could have happen.
When you consider the amount of material that likely polluted this entire engine,the teardown should be only a lesson and a curiosity factor.But with no intention of using it again.Save yourself some trouble and give up the hope to move off this rock to another bare block-short block. Well really more than that!. Again the L31 answer.Affordable at that too with a better 1pc rms.

This advise is from a engine builder not making dime one from this just wanting to help pay back all those that have help me along the way.

billybob6110

ya im gna tear the engine completly doen, see what each component looks like and take it as a learning expereience. take the time, do it right, and ill know exactly whasts inside the motor rather then he said she said type of work.
on the rebuild kits from summit do i want this one: http://www.summitracing.com/parts/su...-300/overview/
or this one: http://www.summitracing.com/parts/su...-311/overview/. only difference i see is the rod legnth .10 and main .10.
since im going to be getting motor bored would i also have them install my new cam bearing and freeze plugs at that time?

midias

Unless you want to be the one to do it then yes

1gary

Lets just say for example the crank end play is way off because of the damaged material flouting around inside the engine causing end play wear and you didn't know or forgot to check for that.Now you have a fresh bore and pistons where the rods are being forced against the the pistons/ bores because of a worn end play ending up with the same result as you have now.That Sir is only one possibility from what you have been talking about.At some point you will find it isn't worth it to risk anymore money on this engine and do what I am telling you is in "your" best interest.

FRMULA88

If your spark plugs are oil fouled

Did you do a compression test, followed by a leakdown test?

this will help pinpoint the issue.

Which spark plugs show oil fouling?:

for example if you have 8,6, 5, 7 fouled itwould mean rear of engine is running hotter than the front.

you have hot cooling system issue...hot spots.. detonation,, piston / ring damage.

billybob6110

i posted a few posts ago about the other block i was getting. i am not messing with the block that has damage.

billybob6110

the compression results are in the post ahead of this. basically every plug had oil on them.

FRMULA88

Find out what's wrong first. if it's not piston/ ring damage was not caused by detonation or pre-ignition.. then you need to look at assembly clearances.

Did you hone the block and file fit the rings yourself?

You will be better off having the block honed by a shop with a honing machine and deck plates. they will do a 100% better job than a hand drill and ball hone.

same with installing pistons / rings.

I understand the desire to build your own engine... but unless you have the proper equipment it will never be right and the rings will not seal correctly. Let a shop do all the precision work to the block & heads, if you want to assemble the short block that's your decision. if you are installing the piston rings, get a ring filing machine it's worth the investment.

Again you may prefer to leave this step to a pro.
a good shop will only charge a couple hundred bucks for complete long block assembly and it will be 100% correct.

FRMULA88

Piston ring sealing is critical for engine to function properly.

As an example, in my engine, losing one piston was an 85 HP loss of power.

The heads, cam, & possibly the stall speed on the converter are probably fine.

Get the engine checked and repaired first a good engine shop.

Also find out the compression ratio so you can run the correct fuel in it.

billybob6110

i havent assembled the motor thats in the discussion now. im going to have a shop hone bore and install freeze plugs and cam bearings. i might also just let them go ahead and install the rings also at that time. everything is up in the air right now, just trying to get old motor out and tore down to see where is lies

billybob6110

i would like to stay as close to 10:1 as i can. i wanna stay on pump gas

FRMULA88

210 cc heads are fine for a 355... (this is intake port runner size)
valve size is just fine

The only difference between a 355 & 383 is the stroke..

The 383 will make a bit more HP and Torque, and not have to rev as high as the 355.

64 cc chambers with flat top pistons and "0" deck should keep you in the 10-10.5:1 CR range... but you need to do the math with gasket thickness you plan to use. this is the most static compression you want to see with iron heads and pump gas.

I had Dart Iron Eagle 215s on my 383.. with larger valves. It ran on 93 unleaded just fine.


1.5 rockers are not enough lift for the cam.

I would change those to 1.6 A good shop may tell you to stagger them (run 1.6 on the intake, 1.5 on the exhaust)

The extra lift on the intake will wake up that cam.

Carb should be in 650-770 CFM range for a 355. 670-770 CFM for a 383.

headers 1 5/8 to 1-3/4 max. Hooker super-comp 2210s bolt right in.


465 HP is pretty easy to make with a 383. The engine will be very streetable
you will need a vacuum can to run power brakes because of the cam.

A 355 will be fine also.

billybob6110

would it be cheaper to buy this? http://www.summitracing.com/parts/sum-150100/overview/

FRMULA88

Most times the carb is oversized for the combo making tuning very difficult for the beginner..

FRMULA88

The Summit block would be better than a junk block of unknown origin.