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Considering buying a 383 stroker 1975 with a blown head gasket. Seller says; "Car has center bolt heads and valve covers. I don’t know a super lot about engines but the engine was built from a guy that was building engines for Busch nascars."
He says no damage to head or motor from blown gasket. Any special considerations about the blown gasket when thinking about purchasing this car? Head gasket is a pretty simple job, right or is the 383 with thse center bolts different?
Center bolt heads are vortec or vortec styled head. I wouldn't assume it just needs a heads gasket. You don't know why it blew or if it overheated after the failure. It might need a gasket, it might need new heads, but it might also need a full rebuild. It's a gamble, I wouldn't make that bet unless the price made sense enough to price in a new motor.
Center bolt heads are vortec or vortec styled head. I wouldn't assume it just needs a heads gasket. You don't know why it blew or if it overheated after the failure. It might need a gasket, it might need new heads, but it might also need a full rebuild. It's a gamble, I wouldn't make that bet unless the price made sense enough to price in a new motor.
center bolt/vortec ... No, not necessarily; it's a common misunderstanding
Kinda like being pregnant; Heads are either Vortec or not ... no in between.
True, that center bolt heads arrived about 1985/1986 ... but desirable iron production Vortecs began only about 1996-1997.
What makes a Vortec are its very efficient "fastburn" chambers and its superior flowing intake ports and it unique intake flange; none of the prior heads have those.
AFAIK, 350" aka 5.7L Vortecs have only two production iron casting numbers 10239906 and 12558062... the casting # is under valve cover; in between springs
JMO, most other iron production center bolt heads are rather poor choices; and there are dozens of those YMMV
FWIW, Today, you can buy a brand new (Not reman) GM crate rpo L31 Vortec 350"/5.7L for $3600 ...forged steel crank, steel billet roller cam, 4-bolt main, USA-Made etc https://www.gmperformancemotor.com/parts/12691673.html
From seller now, "The engine came out of a 71 Chevelle was built and stroked at about 11to 1 ratio or something like that with dome top pistons and aluminum center bolt heads . Guy owed me money so I took engine he installed and I’ve owned it for 10 years I’m sorry I’m not a mechanic but this is what I know / was told about the engine"
Its not proper to call someone a liar but I would enquire about receipts for parts / labor verifying it truly is a 383. At tis point there is not any documentation.
Back in the 60s / 70s every old Chevy for sale on the side of the road had a 327 in it according to the seller.
Later, the buyer found instead, a 283 (or even a 265)
Questioning the seller again: "the guy that had the car before me said it was a 327".
As far as unknown mechanical issues, a Leak-Down Test or and a simple Compression Test will tell a lot about what's going on.
This is assuming the seller would not only allow, but would assist you in this task.
In all fairness, some people / sellers just don't want to deal with head-gasket replacement issues due to time restraints or costs involved.
This could be a diamond in the ruff engine.
Last edited by HeadsU.P.; Oct 28, 2021 at 06:42 PM.
Just re-read your original post -- there's NO WAY he can know that there's no damage to head or motor without pulling it all apart and inspecting.... Gasket might have gone all at once and he shut it down, or very slowly dumping coolant into the oil system for months and months.
Sellers says: "Yes coolant is in oil
Have the original motor to that was never built . I Figured has to be rebuilt sometime. The engine in it now has way more horsepower! Still runs . I only figured out I blew the head gasket when I went to check oil to use it . Never saw any over heat light or anything go on"
From seller now, "The engine came out of a 71 Chevelle was built and stroked at about 11to 1 ratio or something like that with dome top pistons and aluminum center bolt heads . Guy owed me money so I took engine he installed and I’ve owned it for 10 years I’m sorry I’m not a mechanic but this is what I know / was told about the engine"
With compression ratio that high and iron heads the likelyhood that it died (blew the head gasket) from detonation damage is high. This would also damage the piston and/or head along with it. If this is the case then a simple head gasket replacement is not going to fix this engine.
It's a craps shoot. How good is the rest of the car? And if you need to rebuild an engine is the price low enough to make sense should that be required.
With compression ratio that high and iron heads the likelyhood that it died (blew the head gasket) from detonation damage is high. This would also damage the piston and/or head along with it. If this is the case then a simple head gasket replacement is not going to fix this engine.
It's a craps shoot. How good is the rest of the car? And if you need to rebuild an engine is the price low enough to make sense should that be required.
The original engine (L-82) also comes with the car separately. He's asking $10k. Paint is excellent, interior is very nice.
The original engine (L-82) also comes with the car separately. He's asking $10k. Paint is excellent, interior is very nice.
If the original engine runs (unknown really) and everything else pretty much works, it sounds like a deal to me. I have the mechanical ability to change engines and work or rebuild an engine so to me it's a deal anyhow. If you have to pay for these things that deal gets pretty skinny pretty fast. Up to you. I would not count on either engine being any good in their current condition, but the original might be, who knows?
The problem with it not currently running is you can't drive it (or can you?). So no way to access the condition of the rest of the drive train, brakes, steering, suspension, heat, a/c etc. other than looking at it. Again another gamble.
Last edited by REELAV8R; Oct 28, 2021 at 04:21 PM.
it doesn't take much expertise or money to cobble together a motor/entry that'll run long enough to start (even one lap) and then park it. Thereby gaining a somewhat handsome purse for finishing in back of a NASCAR Xfinity fka Busch race. Same for Cup & Truck. It's been done quite a lot and still happens. The strategy was once so prevalent that several teams did it season after season. Team names would change but principals were perennial.
So ... just cuz some guy has a local rep for doing NASCAR top 3 series' work; that don't necessarily mean squat or he's good. And I can't recall when either of the three series ran iron heads. T shirt
Assuming that what you're being told (that it is a head gasket), there are a lot of reasons a head gasket can fail...
1) Defective Head Gasket
2) Poorly Prepared Head or Block - Causing the gasket to Fail.
3) Improperly Torqued Head Bolts or Studs
4) Overheating
5) Poorly Maintained Cooling System (Causing Corrosion)
6) Warped Head
7) Warped Block Deck
8) Crazy High Cylinder Pressure (Caused by Detonation - Too Much boost etc. etc. etc.)
Even after you pull the cylinder head - you won't know what you've got till you take some measurements on how true the cylinder head and block face are.
The question you have to ask yourself is IF the car required $1,250 in repair parts (replacement heads, gaskets etc.) - is it still a good deal ?? What about if it needs $4,000 in repair parts (pull motor - surface block, replace pistons - rebalance, new heads etc....) Then assess the probability of each. I would say that it takes a HECK of a lot more to warp a block than to warp a head, but you don't know what the deal with the Compression Ratio really is....
Getting a good engine back under the hood will set you back about $4000 so if you take that into consideration and you still like the deal, go for it. It does not sound like you will be doing the work, right so the cost is a big consideration.
383 Stroker Blown Head Gasket.
