TheSamba.com :: View topic

Wed Nov 19, 2008 6:32 pm

I just bought a 1968 convertible in great condition that seems to run a bit hot. The motor is a 1776 from mofoco and runs at about 220 to 225. Mofoco says 220 is fine but it seems a bit much to me. I had a local vw shop check it out and the timing and tin seems fine and it is not too lean but they did say that the compression is a bit high at 160. Is 220 to 225 in the winter time (outside temp about 70 degrees) to high or am I just worrying too much. It does have a front oil pump mounted oil filter which sits very close to the exhaust pipe which the shop says is causing the heat along with the high compression.

Is the compression too high at 160? Will premium gas help the oil temp with the high compression? Will a chrome filter cover over the filter reduce the effects of the oil filter heating the oil? And finally is 220 to 225 degrees too hot? (The sender is in the pressure relief valve)

Thanks in advance for any advise. I am new to this forum but not new to vw's. This is my fourth beetle.

Wed Nov 19, 2008 6:44 pm

trfvw wrote: I just bought a 1968 convertible in great condition that seems to run a bit hot. The motor is a 1776 from mofoco and runs at about 220 to 225. Mofoco says 220 is fine but it seems a bit much to me.

So, you don't trust what Roy is telling you? 220 is right where you need it to be, don't touch a thing. Just make sure you use the correct grade, and stay away from the SM/SL rated oils. Look for something with a CJ-4 rating, it's usually sold as diesel truck oil.

Wed Nov 19, 2008 6:48 pm

Doesn't seem too high to me.
Try premium, thats what I use in my 1776.

Wed Nov 19, 2008 6:59 pm

Do you have any guage to monitor oil pressure? 220 is fairly high, but I would be more worried at what your oil pressure is at this temp. I would try like you mentioned to make a heat shield for the filter for now. Do you know what weight oil is in the engine? I would try a high quality oil like Brad Penn, and use a 10w30. Some guys on thesamba have dropped their oil temps by switching to the lighter oil. 220 is doable if you have a good oil, and around 10psi oil pressure per 1000 rpm.

Wed Nov 19, 2008 7:32 pm

Thank you all for your advise.

Quote: So, you don't trust what Roy is telling you? 220 is right where you need it to be, don't touch a thing. Just make sure you use the correct grade, and stay away from the SM/SL rated oils. Look for something with a CJ-4 rating, it's usually sold as diesel truck oil.

Not sure who Roy is? I assume he is with Mofoco. I was certainly not contradicting them, simply a bit ignorant as to how hot is too hot. My local shop is raising their eyebrows at the 220 heat so I was not too sure who to believe. With the advise I am getting here I feel much better about the temp. Also, thanks for the oil advise. I have not yet changed it and I do not know what is in it now but the previous owner told me it had not been changed in a while though they did not drive it much.

Quote: Doesn't seem too high to me.
Try premium, thats what I use in my 1776.
I will try premium
Thanks

Quote: Do you have any guage to monitor oil pressure? 220 is fairly high, but I would be more worried at what your oil pressure is at this temp. I would try like you mentioned to make a heat shield for the filter for now. Do you know what weight oil is in the engine? I would try a high quality oil like Brad Penn, and use a 10w30. Some guys on thesamba have dropped their oil temps by switching to the lighter oil. 220 is doable if you have a good oil, and around 10psi oil pressure per 1000 rpm.
I do have both oil temp and oil pressure gauges. I will check to see if it is running at 10psi per 1000rpm. It did cause the oil pressure light to flicker yesterday when it reached about 225 and was idling. My idle is a bit low at about 600rpm. As soon as I increased the rpms it stopped flickering. Again I do not know what kind of oil is in it.

My local shop and Mofoco both recommended 40 weight oil. My local shop recommended castrol but I have been partial to diesel oils in the past. I currently use Rotella T in my Ford crew cab diesel but I do not know if they make a 40 weight. What weight would be best considering the 220 temp. I might also add that the engine has hydraulic lifters one of which seems too loud. I thought the 40 weight might help.

Wed Nov 19, 2008 8:28 pm

The lower the weight oil you can run the lower your temps should be. But with that in mind, you will need to run thick enough oil to keep your pressure high enough at operating temps. If you were to use a 10W30 weight, your oil temps maynot get to 225. If the temps do get to 225, and you don't have the 10psi per 1000rpm, you'll need a heavier oil. This is maybe why Roy from Mofoco is suggesting the 40 weight. Maybe he feels that this is what you'll end up needing to maintain your pressure. There has been a lot of talk about the Brad Penn oil because it contains a higher amount of a Zinc additive that controls/prevents wear in A/C Engines. This is what I would seek out as an oil, but there are plenty of people using an off the shelf Castrol, or Valvoline. The Rotella also has a good bit of the Zinc additive, so if you do end up needing something heavier than a 10W30, I think the Rotella comes in 15W40.

As for one of your lifters being loud, hydraulic lifters shouldn't make any noise at all. I would talk with Roy from Mofoco about how to adjust the valves. The hydraulic lifters shouldn't have any valve lash/play, so maybe you just have an out of adjustment valve.

Wed Nov 19, 2008 10:55 pm

Quote: As for one of your lifters being loud, hydraulic lifters shouldn't make any noise at all. I would talk with Roy from Mofoco about how to adjust the valves. The hydraulic lifters shouldn't have any valve lash/play, so maybe you just have an out of adjustment valve.

I adjusted them two turns past contact as instructed but one of them is "mushy" when you push on the lower part of the rocker. I think it may have some air in the lifter. Not sure how to deal with it.

Thu Nov 20, 2008 1:11 am

What year is the cabriolet, they tend to have less cool air intake vents than a hardtop bug. Try propping the bottom of the deck lid open a couple o2 inches next run for a test.

Thu Nov 20, 2008 5:56 am

and stay on pump 87, unless the compression ratio is higher than 10:1, there is no sense in wasting the money.

and remember, bigger motor will run a tad hotter.

Thu Nov 20, 2008 1:51 pm

Quote: and stay on pump 87, unless the compression ratio is higher than 10:1, there is no sense in wasting the money.

I do not know what the compression ratio is but the compression is about 160. Approximately what compression ratio would result in 160 psi?

Thu Nov 20, 2008 1:53 pm

Quote: What year is the cabriolet, they tend to have less cool air intake vents than a hardtop bug. Try propping the bottom of the deck lid open a couple o2 inches next run for a test.

The car is a 68. It does have vents in the deck lid but none of coarse above the deck lid.

Thu Nov 20, 2008 3:19 pm

I would prop open the bottom of the lid with a tennis ball and see if that helps. I just recently switched from 15w-40 to Brad Penn 10-30 which lowered my temps from 220 to 190. If it's too thick, it's not all passing through the cooler.

Thu Nov 20, 2008 4:42 pm

trfvw wrote: Quote: and stay on pump 87, unless the compression ratio is higher than 10:1, there is no sense in wasting the money.

I do not know what the compression ratio is but the compression is about 160. Approximately what compression ratio would result in 160 psi?

It's kind of hard to judge compression ratios by cylinder pressure only. I would start with the highest octane pump gas as a stable known variable. Then once you do some experimenting with the oil, oil filter heat shield, and decklid prop, you can experiment with lower octane. Air Cooled VW's make quite a bit of racket by themselves, and it sometimes can be difficult to hear, or realize the engine may be pinging.

Thu Nov 20, 2008 4:55 pm

Quote: I just recently switched from 15w-40 to Brad Penn 10-30 which lowered my temps from 220 to 190. If it's too thick, it's not all passing through the cooler.

SkrapMetal, your oil temp went from 220 to 190 with just an oil change? Were there any other changes done at the same time or just the oil difference?

Thu Nov 20, 2008 4:57 pm

trfvw wrote: SkrapMetal, your oil temp went from 220 to 190 with just an oil change? Were there any other changes done at the same time or just the oil difference?

Just the oil change did that. With the thicker oil, I would have to slow down on the interstate to bring down the temp. After switching, I made a 6 hour round trip drive, averaging 65-70mph, and my oil temps would not go over 190F, no matter what I did.

gkeeton@zbzoom.net wrote: I would start with the highest octane pump gas as a stable known variable.

Highest octane? Why? Higher octane gas is harder to ignite. my 1915 has 8.5 compression, and ran excellent on 87.

Thu Nov 20, 2008 5:40 pm

Thanks for the tip SkrapMetal. I found a local supplier and arranged to pick up a case tomorrow. By tomorrow evening I should be able to change the oil and hopefully run a bit cooler.

Thu Nov 20, 2008 10:13 pm

SkrapMetal wrote: gkeeton@zbzoom.net wrote: I would start with the highest octane pump gas as a stable known variable.

Highest octane? Why? Higher octane gas is harder to ignite. my 1915 has 8.5 compression, and ran excellent on 87.

Yes, your 1915 probably did run excellent on 87 octane with a relatively low 8.5:1 compression. If your compression is unknown, like trfvw's, a higher octane gas will work with high compression, or low compression. Low octane gas will only work with low compression. Running high octane gas will assure the engine won't ping, and you can rule out detonation as one of the causes of heat. If he does all the other modifications, and his temps stabilize, then he can start using lower octane fuel to see if his temps rise back up. If the temps stay the same, he can continue with the lower octane. If they raise up, the engine may be detonating, and he'll probably need to go back to the higher octane.

Fri Nov 21, 2008 8:42 am

I get what you're saying, but I'm not sure what all that has to do with oil temperature. Detonation would effect the head temps and he hasn't said anything about them at all.

Fri Nov 21, 2008 8:59 am

Let's get all the facts right to start...

1) 1776
2) External oil filter, what about an external cooler = no?
3) What kind of cooler are you using? Doghouse cooler?
4) If it's a doghouse cooler, does it have the hoover bit installed?
5) Do you have the fan shroud louvers installed?

Lastly, I don't think I have ever even heard of compression as high as 160 in a type 1 engine. Most people would probably love to see that. Under what condition and using what tools did you measure that?

Fri Nov 21, 2008 11:44 am

Quote: Let's get all the facts right to start...

1) 1776
2) External oil filter, what about an external cooler = no?
3) What kind of cooler are you using? Doghouse cooler?
4) If it's a doghouse cooler, does it have the hoover bit installed?
5) Do you have the fan shroud louvers installed?

Lastly, I don't think I have ever even heard of compression as high as 160 in a type 1 engine. Most people would probably love to see that. Under what condition and using what tools did you measure that?

1. 1776 Yes
2. No external oil filter
3 Doghouse cooler Yes
4. I do not know about the hoover bit. I will check this evening. Is it possible to check with the engine in the car? Will I need to remove the fan shroud to get to it?
5 The fan shroud is new and was just installed since two of the internal air fow vanes were loose.

Since the bug ran great but was a bit hot I checked the obvious things, timing, belt condition etc. and after finding nothing unusual I took it to the local bugformance shop to see if they could find anything that I was missing. They replaced the fan shroud (I do not know if the new one has louvers) and they checked the timing, which was fine, and they checked the compression on cylinders 3 and 4. They told me that the compression was a bit high at 160 and probably contributed to the heat. They did not check 1 and 2 since they were not suspecting compression issues, just checking to see how high the compression was overall, and the dual carbs limit the available space. If 160 is unreasonably high I can recheck it myself but I would think they would know how to check compression.

Thanks