350 block, 327 crank, domed 327 piston, QT20 Cam?

[The Swed]

My son bought a motor a year ago that was in a Derby car his and buddy ran out of money and was done with the Derby seen. My son started the motor and said ran great. He paid $700 and pulled it out. Now he asked if I wanted it for my C20. Here's what I've been told it had two hours on the motor, it's a 350 block, 327 crank, domed 327 pistons and a QT20 cam. Please share your thoughts!

[MARKDTN]

No idea what a QT20 camshaft is. A quick Google search did not yield anything good.

You have a 327 with pop-up pistons. Do you know what heads it has? With small chamber heads you might have some pretty high compression. Overall though, a 327 is a fine engine, nothing wrong with that.

I know just enough about demo-derbies to be dangerous, so take this with a grain of salt. I would worry it had been over-reved or run out of water and overheated. I might be tempted to at least put a set of bearings in it. 2 hours is not really a full picture for a derby car. Did he get knocked out in the first 5 minutes 24 times or did he get to the finals 2 times-or somewhere in between?

[The Swed]

I was told it was a complete rebuild... With two running hours

[cooperhw]

Chances are it was built for something "Exactly Polar Opposite" from what you are wanting to go down the road and not suck down gas at a fast pace. It was probably more designed to get up on top of the power band quick, outta the hole so to speak. Might want to do a compression check to see where it's at? It it's not too high, a cam swap might make it more what a truck going down the road would like.

[The Swed]

The only thing I can find about the TQ20 is was used on a 66 truck... So it seems to be an old school cam... Not much using a 327 crank on a 350 block... I'm completely lost... But I was give the name of the builder of the motor so I hope talk to him tomorrow. Sure is a good to learn a lot it's the cost that I'm worried about!

[MARKDTN]

Both 327 and 350 use a 4" bore block. Before 68 the 327 was a small journal crankshaft and as such no 350 block would fit it. From 68-70 the 327 was a large journal crankshaft (and same crank as a 307). It will go right into a 350 block. Many 327 4-bolt main engines have been made this way since the factory never made one. The rods are the same for LJ 327 and 350 so that is not an issue. With 327 pistons the swap is complete.

Again, my concerns would be:
1-high compression with domed pistons.
2-2 hours running in a derby car is not a complete picture. Did he make the main feature or did he go out in the opener?
3-lots of busted radiators and high rpm operation in derby cars-that is what they do. Do you know anything about the car it was in and how it did? Has it been over-revved or overheated?

I'm not saying the engine is no good. I'm saying I would want more info.

[special-K]

I didn't realize people "built" motors for demo derby. I figured they were just run on their last legs since the most likely thing to happen is they lose all coolant and fry.

As with any motor sold as rebuilt or good running condition, I'd have to see and hear it run and check it's vitals. Otherwise, it's just an old motor

[agawam]

here I go again, people tell me I'm a liar, I have a 68 327 with 4bolt mains steel crank fulie heads an factory forged 11:1 pistons, this came in a 68 nova, vynal seats rubber floor mat no radio or heater, Muncie m22 and 12bolt 410 rear this was a 325hp chevy II, an older gent bought the car in the spring of 69 when he retired and drove the car till his death in 1973, when his grandson inherited the car, he came to me in early 1974 for a paint job, told me he hated the engine, pinged poped and backfired he said, I looked it over and saw it had factory seals on the exhaust manifolds and paint still on most of the bolts, this engine was factory stock to this car, never changed, well the kid came back to my shop wanting to know if I could fix his paint job, so I looked it over, scratches on the hood fenders and roof, "how did this happen" I asked, "me and my buddies changed the engine" he says and opens the hood, "its a 69 327 he said can you fix my car", my response, "where's the engine that was in here" he says it's in the dirt next to my garage" I told him bring me that engine I'll fix you car thats how I got it I still have it today

[cypressbog]

I read on another forum that the 327 came in either large or small journal cranks in 1968/69 and some of the large journals were 4 bolt. Not scientic fact, just what I read.

[Redline novdog]

End of the day it's a small block chevy. If you have that configure in your truck now throw it in. It would be a good time to freshen up what your running now!
The 327 and 350 share the same bore,so basically you would be putting in a (built) 327.
The 327 has a shorter stroke.

[Jrainman]

I would install and see how it runs ,you can always pull it back out , GM 327 engines were and still are very good engines weather is a small Journal or large journal.........that's why chevy put them in just about everything they maid

On a side not to high jack your thread ,Yes the Nova you got your 327 engine from is for real it was a check of the box for the L79 engine upgrade when that Nova was ordered , To bad you don't have that Nova as there was only about 1,200 ordered with the L79 in 1968.

[leadfoot067]

im betting its an erson TQ20

http://usaperform.com/performance-hy...0h-p-1801.html

[MARKDTN]

Originally Posted by agawam

here I go again, people tell me I'm a liar, I have a 68 327 with 4bolt mains steel crank fulie heads an factory forged 11:1 pistons, this came in a 68 nova, vynal seats rubber floor mat no radio or heater, Muncie m22 and 12bolt 410 rear this was a 325hp chevy II, an older gent bought the car in the spring of 69 when he retired and drove the car till his death in 1973, when his grandson inherited the car, he came to me in early 1974 for a paint job, told me he hated the engine, pinged poped and backfired he said, I looked it over and saw it had factory seals on the exhaust manifolds and paint still on most of the bolts, this engine was factory stock to this car, never changed, well the kid came back to my shop wanting to know if I could fix his paint job, so I looked it over, scratches on the hood fenders and roof, "how did this happen" I asked, "me and my buddies changed the engine" he says and opens the hood, "its a 69 327 he said can you fix my car", my response, "where's the engine that was in here" he says it's in the dirt next to my garage" I told him bring me that engine I'll fix you car thats how I got it I still have it today

I would be curious to know the code on the pad and also what block and head castings numbers and dates are.

http://67-72chevytrucks.com/vboard/s...=674698&page=3

This addresses small journal 4-bolt 327s, but also 1968. Here are some of the highlights:

There is no such thing as a factory 327 4-bolt main. You can build one out a large journal block, but none were ever made factory. You will not find a single instance of anybody that can prove there ever was one. Lots of "I heard they did......" but no real evidence. There are pages on Google about this and not one of them I've seen can show any documentation that they exist.

Some have claimed this with a 3892657 casting block. See http://www.nastyz28.com/sbchevy/sblock.html. Mortec says the same things. This is a 1967 only block that was SJ for 327 and 302 but '67 Camaros with 350s got the same 4" bore block with the saddles machined for a LJ crankshaft (http://www.camaros.net/forums/showthread.php?t=143669).

There were no factory built cars with 4-bolt mains until 1969. No Corvettes, Z28s, or SS350 Camaros. If there were some blocks cast in '68, I believe they were for '69 model year vehicles.

http://www.ncrs.org/forums/archive/i...p/t-85289.html
I had not keyed in that there were no 4 bolts in '68 until recently. I had always assumed that the Z28s and SS350s in '68 got them. I knew that the '68 Corvettes did not. So that makes it even less likely that a 327 ever had 4-bolt mains because in '69 the only application for 327 was Camaros and B-bodies-and it was a more base engine as both had 350 performance engines available. By 1970 the 327 was gone and the 307 and 350 was it.
So '68 Z/28s and SS350 Camaros have 2-bolt mains.
http://www.holisticpage.com/camaro/camaros/302.htm

http://www.chevy-camaro.com/faq/chev...o-faq-Z28.shtm

http://www.camaros.net/forums/showthread.php?t=164584

http://www.hotrodders.com/forum/buil...evy-57753.html

Some LJ blocks cross over boundaries. For example, the 3956618 blocks were a 2-bolt for 68-69 327, a 4 bolt for 69 Z28, and 2 or 4 for 69 350. the famous 3970010 (and 3932386) is similar, but has no 68 applications. The raw casting had enough meat in the right places to machine it with either style cap.

No SJ block ever had 4-bolt mains. No documented 4-bolt LJ 327s were built. I could see a possibility in '69 with 0010 or 2386 block, but with all my searching I have yet to find anybody that can prove they have a legit one. And as we know, you could never prove it in a truck even if it did happen because the VIN derivative is not on the engine pad.

There are rumors of Massey-Ferguson combines with 327 4-bolts. The is no evidence this ever happed. Just another part of the legend.

http://www.chevytalk.org/fusionbb/sh...hp?tid/157044/


http://www.thecombineforum.com/forum...et-engine.html

There were industrial and marine engines from Chevy (and Ford and Chrysler). MF Combines did have Chevy 327s, but they were 2 bolt mains. MF combines did get 4-bolt SB engines, but they were 350s. I still maintain 2 things:
1-there is no such thing as a factory 327 with 4-bolt mains. Ever.
2-there were no small blocks with 4-bolt mains before the 1969 model year.

If there is any proof otherwise, I would love to see it.

[Jrainman]

Again not to high Jack this thread from the OP and Im sorry

Yes all your info is correct and yes his L79 was a 2 bolt main but with a forged crank as you know most large journal were cast cranks 68-69 and all small journal 327s had forged cranks ,

certain large journal 327s came with forge cranks not many were made and not many survived because this crank was looked for by the track guys

Its not a 4 bolt ,but it is a L79 and like I said you can find L79 engines but they were in the corvette mostly ,chevelle had the L79 option also but again not many checked the L79 box . the Nova had only 1200 plus ordered , and yes he is correct it came with the M22

Like I said to bad he did not have the Nova that the L79 came out of that car is worth a small fortune ,it is one of the original Sleeper cars

[special-K]

The large journal '68 C/20 TH400 4bbl 327 I built came with a forged crank. I knew the question would be if it had one or not, which it did, but didn't think it was that unusual

[The Swed]

Thanks for all the information! No worries about the different directions the subjects it went on I've learned a lot and this was a wild shot in the dark from the very beginning with a lot here say on my part. I still haven't heard from the builder yet. I'm in my sixth week of a complete right hip replacement, all this free time and can't go out and work on the truck... :/

[MARKDTN]

Originally Posted by Jrainman

Again not to high Jack this thread from the OP and Im sorry

Yes all your info is correct and yes his L79 was a 2 bolt main but with a forged crank as you know most large journal were cast cranks 68-69 and all small journal 327s had forged cranks ,

certain large journal 327s came with forge cranks not many were made and not many survived because this crank was looked for by the track guys

Its not a 4 bolt ,but it is a L79 and like I said you can find L79 engines but they were in the corvette mostly ,chevelle had the L79 option also but again not many checked the L79 box . the Nova had only 1200 plus ordered , and yes he is correct it came with the M22

Like I said to bad he did not have the Nova that the L79 came out of that car is worth a small fortune ,it is one of the original Sleeper cars

Yes, that car would be worth a lot now. I agree with all you said. The L79 was a very stout engine. I do agree that some LJ 327s could be had with steel cranks and many of the SJ 327s did.

I might have gone a little overboard on this, but 4-bolt 327s are quite the urban myth. I did a bunch of research on the other post and here I gathered it all in 1 place so that it could be more easily accessed. As of yesterday, that guy had not been on since June. I am still waiting for his info and pictures.

[GASoline71]

4 bolt main 327 = unicorn



Gary

[agawam]

Ok as I said people say I'm a liar, think what you like , I know what I have, the engine is in storage and I guess I'll have to dig it out once again, for photos stand by this will take a while

[GASoline71]

Send it to the GM historical archives... you have the only one in existence.

Gary

[GRX]

Careful mixing crankshafts between engine sizes. They were factory balanced to engine size, and therefore weights, of related rotating components. That is to say while the cranks may physically interchange with each other, and have the same stroke & casting numbers, a 307 having smaller bore & pistons will not be balanced the same as a large journal 327 crank. It is possible to use the crank from a larger displacement engine in a smaller one. A 350 crank in a 305 is the most common one. Going the other direction is inviting vibration issues. Have seen it many times. That said, having the rotating assembly balanced should be part of any good engine rebuild regardless whether components are mix matched between displacements or not.

[Redline novdog]

GRX. Thanks for bringing that up! All the parts,bore,stroke,compression,quecnh.This thread is not about that but Way cool!! Should there be/is there an engine build thread here! We rely on Nasty z28 or mortec. You guys have more to input!
Sorry I should start a new thread!

[MARKDTN]

Originally Posted by agawam

Ok as I said people say I'm a liar, think what you like , I know what I have, the engine is in storage and I guess I'll have to dig it out once again, for photos stand by this will take a while

Be sure to include:
block casting number
block casting date
info on pad (engine code)
head casting number

Have you had the pan off? Some LJ blocks cross over boundaries. For example, the 3956618 blocks were a 2-bolt for 68-69 327, a 4 bolt for 69 Z28, and 2 or 4 for 69 350. the famous 3970010 (and 3932386) is similar, but has no 68 applications. The raw casting had enough meat in the right places to machine it with either style cap. Just because you have one of those blocks does not make it a 4-bolt.

[mmiddle]

If memory serves me correct..... A "TQ20H" Cam is an old Erson part number.
RPM 2,000- 4750 ADV. Dur.- 292IN/EX DUR@.050 - 214IN/EX Lift - .449 IN/EX Lobe SEP. 111

It is a very mild cam with a mostly smooth idle. pretty good for a bone stock DD work truck, but not much else. Probably NOT a good cam for high compression engines. I ran one back in the early 90's and was not impressed with its performance.

I know your OP said "QT20 cam" but it is likely a "TQ20H"