914
New Reader
6/23/19 8:56 p.m.
The piston to deck clearance appears to be currently .045”.
Although I measured it with the pointy end of a caliper,... it makes sense considering the block deck height looks stock - still has serial number stamps on flange.
Deck on a stock block = 9.025”
1/2 of the 3” stroke crank 1.5” + 5.7” rod length + 1.780” piston height = 8.980” which is .045” below 9.025”.
I am assuming the piston height at 1.780” - even though I have not actually measured them - after reading many manufacturers of replacement piston are .20” under stock height (1.800”) to allow space for decking the block if required during rebuilding.
Does this sound right?
914
New Reader
6/23/19 9:05 p.m.
If it does this online compression calculator results are not too inspiring as is with heads I have....
914
New Reader
6/23/19 10:28 p.m.
... Now if I went with:
Keith Black hypereutectic .040” pistons they are 1.805” tall
And
58cc 305 heads
I should be up to 9.33 to 1
My question with this is will the quench only be .035” ? Is that ok? I have read in many places you should maintain .040” to .045”.
914
New Reader
6/27/19 11:15 p.m.
Well...I found a pair of take off 416 heads for $30 - going to clean them and see what sort of shape they are in.
I also bought the Keith Black pistons that are 1.805” tall - which is likely .025” taller than the ones I have now. So not changing the block at all I should be .020” down the hole rather than .045” which should make a big difference.
Fbamj
None
10/31/19 8:41 a.m.
Kind of late to the show but here's some info for you. Most chevys have .040-.045 deck height from factory. I go with a rule that if cam lift is over.454 put screw in studs for rocker arms. You can pin them but that sucks just do screw in. Not trying to start a war on crank stroke here but any stroke will turn 7000 rpm pretty much the same time speed(seat of your pants reference). It all depends on valve train set up mostly. Yes lite weight rotating assembly helps but on a budget not feasible. Your 283 crank is probably steel. It would take 700 hp, a cast crank can handle 500hp. If you want to balance motor that's good, buget minded don't waste the money. The parts your putting in it will not require it. As far as 305 head go I have never put any on a 283, we don't put them on engines that are for driving around, racing yes. They don't flow enough exhaust on 4 in bore and tend to break ring lands. My work fine on 283 no idea. If you want to speed time at 7000 rpm solid lifter is your choice. Hyd cams with stock lifters fizzle out at about 6500 rpm. Yes a hyd cam can pull 7500 rpm. But your killing the lifter and longevity suffers.
Good luck with the build looks fun!
SkinnyG
UltraDork
10/31/19 9:26 a.m.
How do 305 heads break ring lands on a 4" bore?
Damn those compression calculators! They always ruin my fun and cost more money than they are worth.
Carry on, as a teen I built many a mix and match SBC.
Fbamj
New Reader
10/31/19 3:28 p.m.
Detonation, I guess never really tried to figure it out. They seem to work fine on dirt track cars. But on street cars that get drove a lot they break top ring lands. I just run a thin felpro gasket or mill the E36 M3 out of the head to get the compression I'm after. It helps that I own the shop.
Fbamj
New Reader
10/31/19 3:31 p.m.
I did not say e36 m3. I mill the correct amount off a 350 head. That I'm after.
In reply to Fbamj :
Apparently you don't seem aware of the word filters on this forum. Certain 4-letter words are automatically replaced by a code term to keep this forum family friendly. E36 M3 translates to the $h-- word. There are others. Berkeley for the F-word and Bob Costas for the P-word for example. You type in the word and the filter automatically replaces it with the code word for it.
Fbamj
New Reader
11/5/19 9:49 p.m.
No I didn't but I found it funny after I thought about it later. I like the Bob costa!
SkinnyG
UltraDork
11/6/19 12:13 a.m.
I'm on year 6 of my 350 with 305 heads (posted/described near the top of this very page).
Same pistons. Daily driven.
Well.... This project has been on hold for a couple months. I ended up buying a pretty modified Audi TT and I really like it. In fact I like it so much I may not keep and finish the 914.
914 - pros
- Very rust free and on its way to being awesome
- Will be extra awesome with the v8
- I have it now and I know every inch pretty much
- Very cool car and hard to find for cheap anymore in solid shape
914 - cons
- I don't have the space for 2 project-ish cars
- I don't really have the space, money or time to finish it well in thew next couple of years
Audi TT - Pros
- 400hp with 4 wheel drive
- Fully driveable right now
- great condition 1 owner car
Audi TT - cons
- Will never be as cool as the 914..
- Could explode at any time?
- Not as fun from an engineering and project perspective
If anyone in the lower mainland BC/upper Washington is looking for a great project maybe the 914 should be for you..
914
New Reader
11/17/19 4:35 p.m.
I have decided to keep working on the 914 until it is sold.
The flared fg rocker panels come “needing final fitting” and for the most part they fit pretty well. The rear section of both however did not line up with the rear flares once the jack holes were cut open. More likely the flares were placed slightly further back (1/2”) than the ideal location dictated by the rockers.
Anyway, I cut and extended the flares 1/2” on one side and 3/8” on the other and things are looking much better.
Back:
Front :
Just a heads up on fit-ment issues, learned on a parallel project.
1. Front of the motor clearance to the firewall, resulting in the motor having a nose down mounting. The valve cover clearance to the bulk head is an issue, one of them that starts the issues with all things mounted on the front of the motor. The potential for leaks from the remote water pump might have you think about adding an access point to the rear bulk head/firewall. Or resigning your self to lowering the motor to fix issues.
2. The nose down mounting results in the carburetor mounting/ float level compromise. Mounting the carburetor backwards to make the throttle linkage easier to connect, but the manifold might be a spread bore design that might not work with the reversed carburetor. The fuel surge issues with the reversed carburetor/float level can be fixed, think boat. A really fast boat.
3. A low rise manifold will help keek the air intake below the engine cover, compromising the air flow into the motor. But it keeps the car looking stealth.
4. Making room for the distributor requires cutting the sheet metal of the rear trunk. The mounting of the engine, the height of the installed distributor with the HEI coil and the rear trunk lid want to not work together. Under acceleration the rotation of the motor might make contact with things they should not make contact with.
We are still learning on this project.
David
914 said:
Bought some freshly redone early SBC “power pack” Gm heads - for the 283 I don’t own yet.... Date stamp 1963. All new valves, guides, seals, aftermarket springs and aluminum retainers. $50 for the pair .
These were the factory upgrade (barely) heads for 283’s and early 327’s. These heads came stock on 250hp 327’s which puts them right in the power range I am looking for. Certainly better heads out there but for the price and intended power target these should be just fine.
I hate to pick nits but when you are talking about pre 1975 numbers those are gross horsepower numbers, not net. Plus they often had a fudge factor up or down depending on marketing and insurance.
914
New Reader
11/19/19 1:41 a.m.
RichardSIA said:
Be a shame to not finish it now.
If you sell it, you WILL regret it later.
I only have eight projects going currently so should not even ask, but how much?
Yeah I am pretty sure you are right but the timing, available space and resources to finish the 914 properly are limited and the TT is very close to being done.
We’ll see.... maybe it won’t sell and i will be stuck with it
914
New Reader
11/25/19 11:55 p.m.
Been working on the 914 as time permits and now have the passenger side in high build primer. Hope to have the drivers side sorted out in the next few days.
914
New Reader
1/12/20 8:36 p.m.
Drivers side door and front fender done now. As is the trunk lid and rear tail light fascia. Slow progress with lots of other projects on the go.
914
New Reader
1/16/20 11:07 a.m.
Rear trunk lid and tail light fascia mostly done. Still need a slight skim below the driver's tail light.
914
New Reader
1/19/20 10:20 p.m.
Fully in high build primer now.
914
New Reader
1/28/20 12:04 a.m.
Back on its wheels and partly reassembled.