New engine and exhaust...overheating?

[Wxman2000]

So here's the deal. I just got my car back from a local VW shop a week or so ago. My old engine was pretty much shot, so I brought it in for a swap to a new engine. Went with pretty much everything new under the decklid while it was getting done. Here's what I ended up with:

-1915 engine w/oil filter Pulley is a 6.75", so slightly smaller than stock
-34 Pict 3 carb
-All new tin, doghouse oil cooler, SVDA distributer and a close to stock style exhaust. New J tubes, heater boxes, the whole 9 yards.
-Freeway flyer trans (newly rebuilt 1 year ago)

Long story short, since it's a new engine and I wanted to take care of it, I put one of the Save My Bug temp sensing dipsticks in to monitor while I'm driving.

I've been driving it to work every day and it runs amazing. But here's the deal, going to work in the morning (18 miles mostly 45-60mph) I don't see even a flicker of the oil light that's coming from that dipstick.

However, the past two days coming home in the afternoon, again 18 miles 45-60mph, the oil light will flicker then come on steady when about half way home. I've tried dropping speed, shifting into 3rd when able, etc. but the light stays on steady until I'm home. Outside temp has been 75'ish each day

I checked my timing again today before coming home, thinking that may be the issue but I'm sitting at about 9.5 BTDC at idle, and 30 at 3500rpm with the vac line disconnected and plugged. So timing looks spot on.

One thing with the engine rebuild that I'll be changing when the parts come in are swapping over to stock black valve covers as I've heard they can decrease temps a bit. Other than that, I'm not sure where to look next on a fresh engine.

I've heard rumors that a fresh engine may run hot for a while until broken in...is there any truth to that??

Thanks in advance for any advice!

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[Xevin]

There’s a lot to explore here IMHO.

What year bug?

J tubes and heater boxes/heat exchangers?

Freeway flyer? So how is that set up?

1915cc engine and 34pict carb.

Why the smaller then stock pulley?

Your fan shroud? Does a doghouse oil cooler fit in that? I don’t know how that works on an early style shroud. I’m ignorant to that.

What’s the compression ratio? Cam? Deck height? Heads used. And more.

Curious as to the fan they used in that.

What exactly is the exhaust set up?

What fuel pump are you using?

Is that a duel relief case?

What method/technique was used in breaking in the engine?

Detail your oil cooler set up? Full flow? Etc.

You mention cruising 45-60mph and dropping it in to 3rd gear in perhaps an attempt to cool things down. That might not be helping things. Especially with a “Freeway flyer” gearing set up.

What did the builder say about your issue? Who built it?


I’m not a mechanical expert but you need be really detailed on the internet. You have more questions coming your way.

Hope you can get this sorted out?
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Keep on Busin'

[viiking]

What sort of deck lid do you have. Is it vented?

Try the tennis ball under the deck lid trick and go for another drive to see if the temperatures return to normal.

Bigger engine, more heat, same air flow?
_________________
1968 1500 RHD Lotus White Beetle since birth. In the hospital for major surgery
1966 Lancia Flavia Pininfarina Coupe - in the waiting room
Discharged: 1983 Vanagon, 1974 1800 Microbus,1968 Low Light,1968 Type 3

[Igpoe]

Yep, more questions! What viscosity oil is in your motor? Dino or synthetic?
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'73 super.

[MuzzcoVW]

The largest problem I see here is the aftermarket doghouse. I have seen SO many issues with these over the years. They don't cool anywhere as good as original. And there's a lot we can't see and need to know. So same quesstions as above..whats the compression ratio etc? Vented decklid?

[RWK]

Shroud X2. Get a stock dog house or late F.I. shroud.
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73 Type 181
63 Type 113
63 Type 261- 428 071
62 Type 241-378 025 178 530

[AlmostHeavenWV_VW]

Several things jump out to me, which in isolation may not cause overheating, but all combined are likely significantly/completely causing the overheat issue:

--Smaller than stock pulley = less RPM for the fan at any given speed = less cooling
-- FF transmission = lower RPMs = less cooling fan spin
-- Non-doghouse, aftermarket fan shroud
-- Larger displacement engine = more Vroom = more heat

Other things (also somewhat covered above)
Poor carb adjustment
Vacuum leaks
Over-advanced timing
Dragging brakes/tight bearings
_________________
1973 Standard Beetle
1600DP AK case
Solex 34PICT3 Carb
Bosch DVDA 205AJ Distributor

[MuzzcoVW]

Also something that's obviously missing with the aftermarket shroud/doghouse is the thermostat and air directing vanes inside said shroud. At least you need those even if the tstat is removed (which i DO NOT recommend)

[Cusser]

[MuzzcoVW]

[Wxman2000]

I’ll try to answer everything as best I can, so here goes.

-1969 bug with a 73 body
-freeway flyer just has taller than stock 4th…other gears are the same as stock
-4 vents on the deck lid
-It does have the stock setup with heat exchangers
-As for the smaller than normal pulley, that’s just what the shop put on there
-Engine specs I’m not sure about all (cam, etc)
-Fan appears to be the correct size for the shroud
-Fuel pump is what was on there when I bought the car years ago. Not exactly sure the specs, it’s an electric pump up front under the fuel tank
-going to the shop today to ask, but their hours and mine are tough to line up which is why I checked on here first for some advice before I go in
-tried the tennis ball trick today…no change
-oil is conventional valvoline 10w30 with hi zinc content, per recommendation from the shop

Hope this additional info helps!

[ashman40]

My input...

Replace crank pulley with a stock (7in) size pulley to increase the fan rpms to get back cooling capacity. Unless you are running a race car that only runs on a track... stock size crank pulley is all you should be running. Aluminum pulley with degree marks are fine, as long as they are stock diameter.

Retard your timing 2deg to 7.5BTDC @idle.
When you say the timing is 30BTDC @3500rpm, is this the max mechanical advance? Some aftermarket distributors will continue to increase ignition timing up to 3800rpm. So 30BTDC @3500rpm could increase to something like 34BTDC @3800rpm. You want the max mechanical advance to be limited to 28-32BTDC at ANY rpm.
Also, 30 or 32BTDC is not "better" than 28BTDC. Some engines just run better with less max timing. Don't discount 28BTDC as a max timing.

Use a tennis ball and crack your engine decklid open on your ride home. This makes a greater volume of cool air available to your fan and carb. Both benefit cooling as well as engine performance. If this results in reduced oil temp it means you lack sufficient cool air while the deck lid is closed.
The downside is road dust getting into the engine compartment.

Make sure the seals around the engine tin perimeter keep as much of the hot air blowing out below the engine from flowing back up into the engine compartment. Any openings will allow hot air to recirculate and heat the engine more than needed.

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AshMan40
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'67 Beetle #1 {project car that never made it to the road }
'75 Beetle 1200LS (RHD Japan model) {junked due to frame rot}
'67 Beetle #2 {2019 project car - Wish me luck!}

[Lingwendil]

40x35 heads?
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73 super beetle thread http://www.thesamba.com/vw/forum/viewtopic.php?t=649622 Back on the Road!

Modify your Kadrons for SVDA http://www.thesamba.com/vw/forum/viewtopic.php?p=8115884#8115884

Cast iron VJU4BR8 SVDA reference thread- https://www.thesamba.com/vw/forum/viewtopic.php?t=...mp;start=0

Need replacement filters for original Kadron aircleaners? WIX #42087 is a perfect fit, as is Napa Gold #2087!

[Wxman2000]

About forgot. Here’s the style muffler installed

https://www.jbugs.com/product/3418.html

[Wxman2000]

[Pruneman99]

Stock heater boxes? Or 1.5"?

[Wxman2000]

[Wxman2000]

I snapped a couple picture best I could of the fan in there.

[beetlenut]

I had big heat issues when I first ran my newly rebuilt engine too. Melted part of the engine seal. I have a VS muffler similar in design to the JBugs one you're running. The primary tubes coming off 2 and 4 ran extremely hot. I had to end up wrapping them with a header wrap.

I also went to 0w30 oil, and that made a noticeable difference. You didn't say how many miles you have on the engine yet. You realize it's still breaking itself in and seating everything. How many times have you changed the oil? You're sure you're not jetted too lean right?
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scrapyards are for quitters
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[Wxman2000]

I’m still in the breakin period. They told me first oil change and valve adjust once I hit 500 miles. So far I’ve put about 300 on it. That was once concern I had, was it running hot due to it breaking in? Is that a normal thing?

Thanks for the advice on wrapping around some of the exhaust areas if needed.