SOT - Chev V8 Info, Want to educate myself on engines Options

[riverman]

Before I go out and buy my motor for my conversion, I want to be sure I'm getting what I want and I also need to learn some things so I know what I'm talking about.

First off, I'm not a real 'motor-head' and everything I've learned about 914's I've just picked up as I've gone along. This forum has been an awesome resource so far. Now that I'm getting ready to buy my motor, I need to get educated on Chevy small-blocks. I realise that this forum isn't the best place for this discussion, but if one of you more experienced and knowledgable members could push me in the right direction, I would really appreciate it. What I am looking for are websites or forums that can provide me with general knowledge about SBC's and what performance up-grades are available.

My initial research has me leaning towards a 305 because it's torque characteristics seem to match up best with the 901 tranny. I'm not looking for a super powerful engine, just something in the 225hp (or higher) range that revs high enough to match up well with the 901's stock gearing. I would also like to keep the low-end torque relatively low to help perserve the tranny. I would also like to learn something about aluminum heads, different cams, fuel injection, and other mods that can be done to small-block Chevy's.

And before all you Suby guys chime in here, I already have the adapter plate, starter, and engine mounts for a Chev conversion so I probably won't turn back.

[Pistachio]

OK, I'd suggest going to your local library & checking out some light reading material by HP Books or SA designs... things with titles like High Performance SBC, How to Hot rod yor SBC, Power Secrets, Rebuild your SBC, Modify your SBC... things like that. They'll all be grouped together in the automotive section at your library. The reason I'd recomend them to you, is they'll all give you a little more in depth analysis of the different bore/stroke combonations & their power charactoristics.

From your post I'd say asking for suggestions/wanting to learn, is a good idea IMO (no offense intended). But the 305 was always intended as a hi TQ engine (small bore, long stroke) compared to a 283, 302, 327 & even the 350 (on a ci/tq basis). The idea behind it's advent was to create the TQ needed to move the mass without having to feed the displacement of a 350. I know people use 305's, but really TQ is what's going to blow your 901 apart & on a CI basis, the 305 out performs a 350 in this area (in stk trim) Really the "ideal" would be a large bore, short stroke engine, but those are pretty darn hard to find in a junk yard anymore.

Web reference?
Try Chevy High Performance
Super Chevy
Popular Hot Rodding
& GM High Tech Performance

read all the tech articles - BUT go to your library!

[SLITS]

QUOTE (Pistachio @ Mar 22 2006, 10:32 AM)

Really the "ideal" would be a large bore, short stroke engine, but those are pretty darn hard to find in a junk yard anymore.

400 SBC

[turboman808]

Dam get a k20 (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)

[Pistachio]

QUOTE (SLITS @ Mar 22 2006, 09:35 AM)

QUOTE (Pistachio @ Mar 22 2006, 10:32 AM) Really the "ideal" would be a large bore, short stroke engine, but those are pretty darn hard to find in a junk yard anymore. 400 SBC

lol... naw. Short Stroke I said! (IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif)

IMO the "ultimate" SBC for a teener (if we can ignore the LSx's) would be a 4 bolt 400 block (4.125" bore) with a 3" crank & 6.250" rods. That's give you about 331 CI of short stroke displacement with an effieciant ring package and a rod ratio of 2.08.

That'd be a rev luv'in shortblock with good mid range TQ production. Run flattop pistons with a 58cc chamber & you could easily run pump gas. Cap it off with some 185cc AFR or 200cc Darts and the right cam & .... (IMG:http://www.914world.com/bbs2/html/emoticons/driving.gif) (IMG:http://www.914world.com/bbs2/html/emoticons/smilie_pokal.gif) Woo HOO! lol...

[Andyrew]

350 destroked.

Thats my trick... I dont know much either, but im going to get the shortest stroke crank I can get in there.. do my valvetrain full roller, and rev to 8 (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)

[Dr. Roger]

are you going to stick with the stock 5 speed or get a modified wide ratio 4sp 901.

making a peaky SBC would be the best like andy suggests. 302's are rare and 327's are getting there. 350's are a dime a dozen.

for driveability, my philosophy is go for the modified 4speed with the higher 5th for lower RPM's on the highway. then make the engine a mid to high rpm motor. no first gear (the weak link) so starting in second which is no problem for the 350.

350 replacement parts are relatively cheap unlike most alternatives.

all ya' got to watch out for is over torquing the transaxle. AKA popping the clutch with sticky tires.....

a skilled driver won't mind the peaky, high winding engine. my CSOB @$$ likes the broader torque band and i have two backup tranny's just in case. =-)

alright! anuther V8! (IMG:http://www.914world.com/bbs2/html/emoticons/smilie_pokal.gif)

[MikeP]

You're biggest problem will be keeping the thing from making TQ and HP. With all the add ons you mentioned you'll have to restrict it in some way. You could get a 350 with low compression and heads that are too big for the motor so you're intake velocity and low end TQ will be low and your rpm band/ power will be up high.

[riverman]

QUOTE (Dr. Roger @ Mar 22 2006, 03:12 PM)

are you going to stick with the stock 5 speed or get a modified wide ratio 4sp 901. making a peaky SBC would be the best like andy suggests. 302's are rare and 327's are getting there. 350's are a dime a dozen. for driveability, my philosophy is go for the modified 4speed with the higher 5th for lower RPM's on the highway. then make the engine a mid to high rpm motor. no first gear (the weak link) so starting in second which is no problem for the 350. 350 replacement parts are relatively cheap unlike most alternatives. all ya' got to watch out for is over torquing the transaxle. AKA popping the clutch with sticky tires..... a skilled driver won't mind the peaky, high winding engine. my CSOB @$$ likes the broader torque band and i have two backup tranny's just in case. =-) alright! anuther V8! (IMG:http://www.914world.com/bbs2/html/emoticons/smilie_pokal.gif)

Ideally, I'd like to stick with a stock 901 because I currently have three of them. However, I imagine most of my driving will be on the backroads and a taller 5th gear would probably be better. I understand Brad Mayeur has some 'H' gears, so I'll have to look into that as well.

[rick 918-S]

try this one! Cool!

[dakotaewing]

Doug -

I know where there is a 331 short block (327 .030 over) that is fresh for a $1000 US in MO. I passed on this motor and bought the 302 SBC
that the same guy had - (he had 4 or so motors that were fresh in his garage, and a Plymouth Superbird in garage #2)...

LMK if you want his contact info -

Thom

[charlesmac]

sorry bout the hi-jack..... but I was wondering why the ford 289/302 isn't used more in 914's. Don't get me wrong, i'm more of a chevy fan than ford, but it seems that ford small blocks would be a justifyable alternative.

[dakotaewing]

QUOTE (charlesmac @ Mar 22 2006, 04:28 PM)

sorry bout the hi-jack..... but I was wondering why the ford 289/302 isn't used more in 914's.  Don't get me wrong, i'm more of a chevy fan than ford, but it seems that ford small blocks would be a justifyable alternative.

The typical train of thought is that the engine is a bit to long -

[riverman]

QUOTE (dakotaewing @ Mar 22 2006, 04:19 PM)

Doug - I know where there is a 331 short block (327 .030 over) that is fresh for a $1000 US in MO. I passed on this motor and bought the 302 SBC that the same guy had - (he had 4 or so motors that were fresh in his garage, and a Plymouth Superbird in garage #2)... LMK if you want his contact info - Thom

Thanks for the info. I'll keep it mind, but I'll probably end up shopping on this side of the border. Importing and cross-border transportation can be deal killers.

[Jack Daniels]

I'm surprised noone's using LS1's in these conversions. Lightweight all aluminum motor with 350hp.

[BIGKAT_83]

I'm just finishing a LS1 conversion now and also have a running SBC350 914 car now. There is another member here with a running LS1 car.
I just finished building a short stroke 283 engine for a friends 914. Just as one was described at the first of the thread 12.5 cr forged pistons 58cc heads and a Rod Simpson II engle cam with Rhoads lifters. I would NEVER do this again. Cost twice as much to build as a flat top piston 350 with half the performance.

If I was interested in a lower horse-powered car. I think instead of a small cubic inch SBC I go with a Japanese V6 engine like a Nissan or Honda .

[byndbad914]

QUOTE (Pistachio @ Mar 22 2006, 10:02 AM)

QUOTE (SLITS @ Mar 22 2006, 09:35 AM) QUOTE (Pistachio @ Mar 22 2006, 10:32 AM) Really the "ideal" would be a large bore, short stroke engine, but those are pretty darn hard to find in a junk yard anymore. 400 SBC lol... naw. Short Stroke I said! (IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif) IMO the "ultimate" SBC for a teener (if we can ignore the LSx's) would be a 4 bolt 400 block (4.125" bore) with a 3" crank & 6.250" rods. That's give you about 331 CI of short stroke displacement with an effieciant ring package and a rod ratio of 2.08. That'd be a rev luv'in shortblock with good mid range TQ production. Run flattop pistons with a 58cc chamber & you could easily run pump gas. Cap it off with some 185cc AFR or 200cc Darts and the right cam & .... (IMG:http://www.914world.com/bbs2/html/emoticons/driving.gif) (IMG:http://www.914world.com/bbs2/html/emoticons/smilie_pokal.gif) Woo HOO! lol...

just grabbed one to quote - not "picking on" anyone in particular...

Pistachio, I would not recommend a 4-bolt 400 block - they crack through the mains webs right under the outside bolts. 350 4-bolts are fantastic, but 400s suck. I used a 400 2-bolt block and converted 2-3-4 main caps to splay mains to have a 4-bolt setup - that works very well. I have seen a fair amount of cracked 400 4-bolts back when I did engine machining and so forth. Just FYI, especially since they are rarer and you will pay extra $$ for something that is essentially not worth it. Put that money into converting to splayed mains.

Secondly, 3" stroke would be seriously short in a 400 block, but doable of course. Rod-to-stroke ratios do not have to be insane to spin. This is where Ford was superior to Chevy - Ford used a rough 1.7 R/S ratio in many of the small block designs where Chevy would go smaller. The best was the 289 Ford with a 1.86 R/S ratio. A 6.250 rod with a 3" stroke at 2.08 is really "long" and not worth it unless you want to head north of 9,000rpm. The 1.25" compression height on the piston is okay because there is virtually no rod angle. R/S ratios at 2+ is Indy car kinda stuff.

My favorite engine of all-time is the 289 Ford from a design standpoint. Gained real appreciation when I helped a guy with a stock but heat treated crank, stock rod (ARP bolts/polished/heat treating so not quite stock) 289 in a 68 Mustang. He would launch the car off the trans brake at 8000rpm with a 150shot of NO, shift at 8500, hit it with an additional 250HP stage, then end up out the back door at 9000rpm. Ran low 9s in that pig of a car. Spin all season long. We would change the bearings annually only because that much nitrous is a bit rough on them.

My normal long-winded self followed with this summary - if you want to build a great SBC big bore/short stroke combo, the most popular and best way to go is 400 block splayed, 327 crank (3.25" stroke large journal steels are hard to find), 6" rods, and the flattops are "off the shelf" from many places (Ross/SRP for instance) with a 1.375" compression height which makes for a great ring spacing as well. It is a 289 Ford in Chevy clothing (1.85 R/S ratio). 353 cubes at .030" over. I built that combo for a ton of local SouthWest tour guys a few years back and works great.

Almost all circle track cars were running this for a while. Now they use longer rods, and a little more stroke, but also have to live at 8500rpm "all day". Typical setup for that is 4.125" bore BowTie block, 6.250" rod, 3.34" stroke. Guess what - 1.87 R/S ratio. Hmmm... 1.85-1.87 R/S ratio for high rpm (in V8 terms 7-9K is high). 1.1" C/H is low but doable (347 Ford stoked 302s run this piston) and makes for a light piston.

Lastly be careful of running a lot of rod angle and thinking it will run pump gas. Dwell kills that quickly. The way to run pump gas is small bore, not big bore, and definitely not dwell. I am at 11.13:1 with flattops and just began to detonate on the dyno at 512HP, so had to switch to race gas to get 525HP. And I have a gnarly circle track tappet cam in it with 105 l/c and 6deg advance (99deg intake!) so I am bleeding off a ton of cylinder pressure and still had detonation. If I had a 2.08 R/S ratio at the compression, I would have detonated way earlier. Your combo would be about 10:1 so would probably make it, but gives up a lot of power with the lower compression.

Andrew - probably best bet for what imply is the 350 4-bolt block and the aforementioned 327 crank with 6" rods. The pistons are also off the shelf in various over-bores (as it is just a 327 piston). The big-bore 400 block helps to unshroud the valves a bit though (IMG:http://www.914world.com/bbs2/html/emoticons/wink.gif)

Of course, now there are Chinese cranks all over and offered in large journal with 3.25" stroke so the hard to find stock steel crank isn't such an issue. And they work great and are cheaper.

Riverman - in terms of using a 305 Chevy - run away, run away (bad Monty Python quote). Just not a good combo. Because you have limited "gear head" experience, the best bet for you would be to check into the Chevy crate motors. They have some nice 350 crate engines that would be a near "bolt-in" for you, meaning your lack of knowledge won't hurt you as quickly. I personally wouldn't use a crate engine because of my background, BUT GM Performance crate engines are perfect for the "average Joe" and reasonably priced when it is all said and done.

Lastly Bill (wberthgo) has an LS series engine in his 914 - can't recall if it is LS1 or 2 or 6. The new LS7 would be cool.

[Mike T]

QUOTE (byndbad914 @ Mar 22 2006, 03:19 PM)

Andrew - probably best bet for what imply is the 350 4-bolt block and the aforementioned 327 crank with 6" rods.  The pistons are also off the shelf in various over-bores (as it is just a 327 piston).  The big-bore 400 block helps to unshroud the valves a bit though  ;)

If I follow this correctly this is a 327 with 6" rods right? That would mean a piston with a 1.375" compression height approximately. Yes?

350 block with a 327 crank = 327


Mike T

[byndbad914]

QUOTE (Mike T @ Mar 22 2006, 03:45 PM)

QUOTE (byndbad914 @ Mar 22 2006, 03:19 PM) Andrew - probably best bet for what imply is the 350 4-bolt block and the aforementioned 327 crank with 6" rods.  The pistons are also off the shelf in various over-bores (as it is just a 327 piston).  The big-bore 400 block helps to unshroud the valves a bit though  ;) If I follow this correctly this is a 327 with 6" rods right? That would mean a piston with a 1.375" compression height approximately. Yes? 350 block with a 327 crank = 327 Mike T

Yep - it is a 327 with a great R/S ratio, with the added benefit of a 4-bolt block from the 350. 1.375" C/H - deck the block to 9" exact and you are perfect. Set of AFR heads (or Canfields) and can make a great combo for Andrew. Put a hyd roller for longevity in a streeter and it would be money. Of course, want to beat it a bit, solid tappet would be cool and lopey. Scary to break-in though! Chevies absolutely suck ass when it comes to keeping the lobes on the cams (IMG:http://www.914world.com/bbs2/html/emoticons/mad.gif)

I am still not sold on the solid roller on the street - I have seen them go about 10,000 miles and drop a roller (shortest spell was about 7,000 for a friend of mine - wiped the whole motor out), but that is not my idea of longevity. the lower spring pressure grinds I have heard can get about 20K miles, but I will believe it when I see it.

[Jack Daniels]

QUOTE (BIGKAT_83 @ Mar 22 2006, 03:03 PM)

I'm just finishing a LS1 conversion now and also have a running SBC350 914 car now. There is another member here with a running LS1 car. I just finished building a short stroke 283 engine for a friends 914. Just as one was described at the first of the thread 12.5 cr forged pistons 58cc heads and a Rod Simpson II engle cam with Rhoads lifters. I would NEVER do this again. Cost twice as much to build as a flat top piston 350 with half the performance. If I was interested in a lower horse-powered car. I think instead of a small cubic inch SBC I go with a Japanese V6 engine like a Nissan or Honda .

Any pics of the LS1 conversion?